-------
1-6
TRAVERSE
POINT
1
2
3
4
5
6
DISTANCE.
% of diameter
4.4
14.7
29.5
70.5
85.3
95.6
Figure 1-3. Example showing circular stack cross section divided into
12 equal areas, with location of traverse points indicated,
-------
1-7
Table 1-2. LOCATION OF TRAVERSE POINTS IN CIRCULAR STACKS
(Percent of stack diameter from inside wall to traverse point)
Traverse
point
number
on a
diameter
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
Number of traverse points on a diameter
2
14.6
85.4
4
6.7
25.0
75.0
93.3
6
4.4
14.6
29.6
70.4
85.4
95.6
8
3.2
10.5
19.4
32.3
67.7
80.6
89.5
96.8
10
2.6
8.2
14.6
22.6
34.2
65.8
77.4
85.4
91.8
97.4
12
2.1
6.7
11.8
17.7
25.0
35.6
64.4
75.0
82.3
88.2
93.3
97.9
14
1.8
5.7
9.9
14.6
20.1
26.9
36.6
63.4
73.1
79.9
85.4
90.1
94.3
98.2
16
1.6
4.9
8.5
12.5
16.9
22.0
28.3
37.5
62.5
71.7
78.0
83.1
87.5
91.5
95.1
98.4
18
1.4
4.4
7.5
10.9
14.6
18.8
23.6
29.6
38.2
61.8
70.4
76.4
81.2
85.4
89.1
92.5
95.6
98.6
20
1.3
3.9
6.7
9.7
12.9
16.5
20.4
25.0
30.6
38.8
61.2
69.4
75.0
79.6
83.5
87.1
90.3
93.3
96.1
98.7
22
1.1
3.5
6.0
8.7
11.6
14.6
18.0
21.8
26.2
31.5
39.3
60.7
68.5
73.8
78.2
82.0
85.4
88.4
91.3
94.0
96.5
98.9
24
1.1
3.2
5.5
7.9
10.5
13.2
16.1
19.4
23.0
27.2
32.3
39.8
60.2
67.7
7:. 8
77.0
80.6
83.9
86.8
89.5
92.1
94.5
96.8
98.9
-------
1-8
Bibliography) that gives the same values as those in Table 1-2 may
be used in lieu of Table 1-2.
For particulate traverses, one of the diameters must be in a plane
containing the greatest expected concentration variation, e.g., after
bends, one diameter shall be in the plane of the bend. This requirement
becomes less critical as the distance from the disturbance increases;
therefore, other diameter locations may be used, subject to approval of
the Administrator.
In addition, for stacks having diameters greater than 0.61 m
(24 in.) no traverse points shall be located within 2.5 centimeters
(1.00 in.) of the stack walls; and for stack diameters equal to or less
than 0.61 m (24 in.), no traverse points shall be located within 1.3 cm
(0.50 in.) of the stack walls. To meet these criteria, observe the
procedures given below.
2.3.1.1 Stacks With Diameters Greater Than 0.61 m (24 in.). When
any of the traverse points as located in Section 2.3.1 fall within
2.5 cm (1.00 in.) of the stack walls, relocate them away from the
stack walls to: (1) a distance of 2.5 cm (1.00 in.); or (2) a distance
equal to the nozzle inside diameter, whichever is larger. These
relocated traverse points (on each end of a diameter) shall be the
"adjusted" traverse points.
Whenever two successive traverse points are combined to form a
single adjusted traverse point, treat the adjusted point as two
separate traverse points, both in the sampling (or velocity measure-
ment) procedure, and in recording the data.
-------
1-9
2.3.1.2 Stacks With Diameters Equal to or Less Than 0.61 m (24
in.). Follow the procedure in Section 2.3.1.1, noting only that any
"adjusted" points should be relocated away from the stack walls to:
(1) a distance of 1.3 cm (0.50 in.); or (2) a distance equal to the
nozzle inside diameter, whichever is larger.
2.3.2 Rectangular Stacks. Determine the number of traverse points
as explained in Sections 2.1 and 2.2 of this method. From Table 1-1,
determine the grid configuration. Divide the stack cross-section into as
many equal rectangular elemental areas as traverse points, and then
locate a traverse point at the centroid of each equal area according to
the example in Figure 1-4.
If the tester desires to use more than the minimum number of
traverse points, expand the "minimum number of traverse points" matrix
(see Table 1-1) by adding the extra traverse points along one or the
other or both legs of the matrix; the final matrix need not be balanced.
For example, if a 4 x 3 "minimum number of points" matrix were expanded
to 36 points, the final matrix could be 9 x 4 or 12 x 3, and would not
necessarily have to be 6 x 6. After constructing the final matrix,
divide the stack cross-section into as many equal rectangular, elemental
areas as traverse points, and locate a traverse point at the centroid of
each equal area.
The situation of traverse points being too close to the stack walls
is not expected to arise with rectangular stacks. If this problem
should ever arise, the Administrator must be contacted for resolution of
the matter.
-------
1-10
o I o
I
-r--
o I o
I
Figure 1-4. Example showing rectangular stack cross
section divided into 12 equal areas, with a traverse
point at centroid of each area.
-------
i-n
2.4 Verification of Absence of Cyclonic Flow. In most stationary
sources, the direction of stack gas flow is essentially parallel to the
stack walls. However, cyclonic flow may exist (1) after such devices as
cyclones and inertial demisters following venturi scrubbers, or (2) in
stacks having tangential inlets or other duct configurations which tend
to induce swirling; in these instances, the presence or absence of
cyclonic flow at the sampling location must be determined. The following
techniques are acceptable for this determination.
Level and zero the manometer. Connect a Type S pi tot tube to the
manometer. Position the Type S pi tot tube at each traverse point, in
succession, so that the planes of the face openings of the pitot tube
are perpendicular to the stack cross-sectional plane: when the Type S
pitot tube is in this position, it is at "0° reference." Note the
differential pressure (Ap) reading at each traverse point. If a null
(zero) pitot reading is obtained at 0° reference at a given traverse
point, an acceptable flow condition exists at that point. If the pitot
reading is not zero at 0° reference, rotate the pitot tube (up to +90°
yaw angle), until a null reading is obtained. Carefully determine and
record the value of the rotation angle (a) to the nearest degree. After
the null technique has been applied at each traverse point, calculate
the average of the absolute values of a; assign a values of 0° to those
points for which no rotation was required, and include these in the
overall average. If the average value of a is greater than 10°, the
overall flow condition in the stack is unacceptable and alternative
methodology, subject to the approval of the Administrator, must be used
to perform accurate sample and velocity traverses.
-------
1-12
3. Bibliography
1. Determining Dust Concentration in a Gas Stream. ASME. Per-
formance Test Code No. 27. New York. 1957.
2. Devorkin, Howard, et al. Air Pollution Source Testing Manual.
Air Pollution Control District. Los Angeles, CA. November 1963.
3. Methods for Determination of Velocity, Volume, Dust and Mist
Content of Gases. Western Precipitation Division of Joy Manufacturing
Co. Los Angeles, CA. Bulletin WP-50. 1968.
4. Standard Method for Sampling Stacks for Particulate Matter. In:
1971 Book of ASTM Standards, Part 23. ASTM Designation D-2928-71.
Philadelphia, PA. 1971.
5. Hanson, H. A., et al. Particulate Sampling Strategies for
Large Power Plants Including Nonuniform Flow. USEPA, ORD, ESRL, Research
Triangle Park, N.C. EPA-600/2-76-170. June 1976.
6. Entropy Environmentalists, Inc. Determination of the Optimum
Number of Sampling Points: An Analysis of Method 1 Criteria. Environmental
Protection Agency. Reserch Triangle Park, N. C. EPA Contract No. 68-01-3172,
Task 7.
-------
DETERMINATION OF STACK GAS VELOCITY AND VOLUMETRIC
FLOW RATE (TYPE S PITOT TUBE)
METHOD 2
-------
1-13
METHOD 2DETERMINATION OF STACK GAS VELOCITY AND
VOLUMETRIC FLOW RATE (TYPE S PITOT TUBE)
1. Principle and Applicability
1.1 Principle. The average gas velocity in a stack is
determined from the gas density and from measurement of the average
velocity head with a Type S (Stausscheibe or reverse type) pi tot tube.
1.2 Applicability. This method is applicable for measurement
of the average velocity of a gas stream and for quantifying gas flow.
This procedure is not applicable at measurement sites which fail
to meet the criteria of Method 1, Section 2.1. Also, the method cannot
be used for direct measurement in cyclonic or swirling gas streams;
Section 2.4 of Method 1 shows how to determine cyclonic or swirling
flow conditions. When unacceptable conditions exist, alternative
procedures, subject to the approval of the Administrator, U. S.
Environmental Protection Agency, must be employed to make accurate
flow rate determinations; examples of such alternative procedures are:
(1) to install straightening vanes; (2) to calculate the total volumetric
flow rate stoichiometrically, or (3) to move to another measurement
site at which the flow is acceptable.
2. Apparatus
Specifications for the apparatus are given below. Any other
apparatus that has been demonstrated (subject to approval of the
Administrator) to be capable of meeting the specifications will be
considered acceptable.
2.1 Type S Pi tot Tube. The Type S pi tot tube (Figure 2-1) shall
be made of metal tubing (e.g., stainless steel). It is recommended
that the external tubing diameter (dimension D., Figure 2-2b) be
-------
1-14
1.90-2.54 cm*
(0.75 1.0 in.)
, 7.62 cm (3 in.)'
TEMPERATURE SENSOR
7H5 £
TYPE SPITOT TUBE
SUGGESTED (INTERFERENCE FREE)
PITOT TUBE THERMOCOUPLE SPACING
LEAK-FREE
CONNECTIONS
MANOMETER
Figure 2-1. Type S pitot tube manometer assembly.
-------
1-15
between 0.48 and 0.95 centimeters (3/16 and 3/8 inch). There shall
be an equal distance from the base of each leg of the pi tot tube to
its face-opening plane (dimensions P^ and Pg, Figure 2-2b); it is
recommended that this distance be between 1.05 and 1.50 times the
external tubing diameter. The face openings of the pitot tube shall,
preferably, be aligned as shown in Figure 2-2; however, slight mis-
alignments of the openings are permissible (see Figure 2-3).
The Type S pitot tube shall have a known coefficient, determined
as outlined in Section 4. An identification number shall be assigned
to the pitot tube; this number shall be permanently marked or
engraved on the body of the tube.
A standard pitot tube may be used instead of a Type S, provided
that it meets the specifications of Sections 2.7 and 4.2; note, however,
that the static and impact pressure holes of standard pitot tubes are
susceptible to plugging in particulate-laden gas streams. Therefore,
whenever a standard pitot tube is used to perform a traverse, adequate
proof must be furnished that the openings of the pitot tube have not
plugged up during the traverse period; this can be done by taking a
velocity head (AP) reading at the final traverse point, cleaning out
the impact and static holes of the standard pitot tube by "back-
purging" with pressurized air, and then taking another Ap reading.
If the Ap readings made before and after the air purge are the same
(+5 percent), the traverse is acceptable. Otherwise, reject the run.
Note that if Ap at the final traverse point is unsuitably low,
another point may be selected. If "back-purging" at regular intervals
-------
1-16
TRANSVERSE
TUBE AXIS
\
FACE
h~-OPENING
PLANES
A SIDE PLANE
LONGITUDINAL '
TUBE AXIS *":
)
\
Dt
*
A
B
PA
NOTE:
1.05 D
B SIDE PLANE
(b)
AORB
(c)
Figure 22. Properly constructed Type S pitot tube, shown
in: (a) end view; face opening planes perpendicular to trans-
verse axis; (b) top view; face opening planes parallel to lon-
gitudinal axis; (c) side view; both legs of equal length and
centerlines coincident, when viewed from both sides. Base-
line coefficient values of 0.84 may be assigned to pitot tubes
constructed this way.
-------
TRANSVERSE
TUBE AXIS
1-17
(b)
LONGITUDINAL
TUBE AXIS
(e)
' J. 01 <+ or -)
j_LJT ^ IT
(f)
(8)
Figure 2-3. Types of face-opening misalignment that can result from field use or im-
proper construction of Type S pilot tubes. These will not affect the baseline value
of Cp(s) so long as a\ and 0.2 < 10°, 01 and 02 < 5°, z < 0.32 cm (1/8 in.) and w <
0.08cm (1/32 in.) (citation 11 in Section 6).
-------
1-18
is part of the procedure, then comparative Ap readings shall be taken,
as above, for the last two back purges at which suitably high Ap
readings are observed.
2.2 Differential Pressure Gauge. An inclined manometer or
equivalent device is used. Most sampling trains are equipped with
a 10-in. (water column) inclined-vertical manometer, having 0.01-ln.
HpO divisions on the 0- to 1-in. inclined scale, and 0.1-in. HpO
divisions on the 1- to 10-in. vertical scale. This type of manometer
(or other gauge of equivalent sensitivity) is satisfactory for the
measurement of Ap values as low as 1.3 mm (0.05 in.) HA0. However, a
differential pressure gauge of greater sensitivity shall be used
(subject to the approval of the Administrator), if any of the following is
found to be true: (1) the arithmetic average of all Ap readings at
the traverse points in the stack is less than 1.3 mm (0.05 in.) hLO;
(2) for traverses of 12 or more points, more than 10 percent of the
individual Ap readings are below 1.3 mm (0.05 in.) H^O; (3) for traverses
of fewer than 12 points, more than one Ap reading is below 1.3 mm
(0.05 in.) HpO. Citation 18 in Section 6 describes commercially
available instrumentation for the measurement of low-range gas velocities.
As an alternative to criteria (1) through (3) above, the following
calculation may be performed to determine the necessity of using a more
sensitive differential pressure gauge:
n
I
T = .
I ^p~
i = 1 ]
where:
Ap. = Individual velocity head reading at a traverse point,
rrni H0 (1n. H0)
-------
1-19
n = Total number of traverse points
K = 0.13 mm H20 when metric units are used and 0.005 in. HpO
when English units are used
If T is greater than 1.05, the velocity head data are unacceptable
and a more sensitive differential pressure gauge must be used.
Note: If differential pressure gauges other than inclined
manometers are used (e.g., magnehelic gauges), their calibration
must be checked after each test series. To check the calibration
of a differential pressure gauge, compare Ap readings of the gauge
with those of a gauge-oil manometer at a minimum of three points,
approximately representing the range of Ap values in the stack. If,
at each point, the values of Ap as read by the differential pressure
gauge and gauge-oil manometer agree to within 5 percent, the differential
pressure gauge shall be considered to be in proper calibration. Other-
wise, the test series shall either be voided, or procedures to adjust
the measured Ap values and final results shall be used, subject 'to the
approval of the Administrator.
2.3 Temperature Gauge. A thermocouple, liquid-filled bulb
thermometer, bimetallic thermometer, mercury-in-glass thermometer, or
other gauge capable of measuring temperature to within 1.5 percent of
the minimum absolute stack temperature shall be used. The temperature
gauge shall be attached to the pi tot tube such that the sensor tip does not
touch any metal; the gauge shall be in an interference-free arrangement
with respect to the pitot tube face openings (see Figure 2-1 and also
Figure 2-7 in Section 4). Alternate positions may be used if the pitot
tube-temperature gauge system is calibrated according to the procedure
-------
1-20
of Section 4, Provided that a difference of not more than 1 percent
in the average velocity measurement is introduced, the temperature
gauge need not be attached to the pitot tube; this alternative is
subject to the approval of the Administrator.
2.4 Pressure Probe and Gauge. A piezometer tube and mercury-
or water-filled U-tube manometer capable of measuring stack pressure
to within 2.5 mm (0.1 in.) Hg is used. The static tap of a standard
type pitot tube or one leg of a Type S pitot tube with the face opening
planes positioned parallel to the gas flow may also be used as the
pressure probe.
2.5 Barometer. A mercury, aneroid, or other barometer capable
of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg) may
be used. In many cases, the barometric reading may be obtained from
a nearby national weather service station, in which case the station
value (which is the absolute barometric pressure) shall be requested
and an adjustment for elevation differences between the weather station
and the sampling point shall be applied at a rate of minus 2.5 mm
(0.1 in.) Hg per 30 meter (100 foot) elevation increase, or vice-versa
for elevation decrease.
2.6 Gas Density Determination Equipment. Method 3 equipment, if
needed (see Section 3.6), to determine the stack gas dry molecular
weight, and Reference Method 4 or Method 5 equipment for moisture content
determination; other methods may be used subject to approval of the
Administrator.
2.7 Calibration Pitot Tube. When calibration of the Type S pitot
tube is necessary (see Section 4), a standard pitot tube is used as a
reference. The standard pitot tube shall, preferably, have a known
-------
1-21
coefficient, obtained either (1) directly from the National Bureau
of Standards, Route 70 S, Quince Orchard Road, Gaithersburg,
Maryland, or (2) by calibration against another standard pitot tube
with an NBS-traceable coefficient. Alternatively, a standard pitot
tube designed according to the criteria given in 2.7.1 through 2.7.5
below and illustrated in Figure 2-4 (see also Citations 7,8, and 17
in Section 6) may be used. Pitot tubes designed according to these
specifications will have baseline coefficients of about 0.99 ^0.01.
2.7.1 Hemispherical (shown in Figure 2-4), ellipsoidal, or
conical tip.
2.7.2 A minimum of six diameters straight run (based upon D, the
external diameter of the tube) between the tip and the static pressure
holes.
2.7.3 A minimum of eight diameters straight run between the static
pressure holes and the center!ine of the external tube, following the
90 degree bend.
2.7.4 Static pressure holes of equal size (approximately 0.1 D),
equally spaced in a piezometer ring configuration.
2.7.5 Ninety degree bend, with curved or mitered junction.
2.8 Differential Pressure Gauge for Type S Pitot Tube Calibration.
An inclined manometer or equivalent is used. If the single-velocity
calibration technique is employed (see Section 4.1.2.3), the calibration
differential pressure gauge shall be readable to the nearest 0.13 mm
H«0 (0.005 in. HpO). For multivelocity calibrations, the gauge shall be
readable to the nearest 0.13 mm H20 (0.005 in H20) for Ap values between 1.3
and 25 mm H20 (0.05 and 1.0 in. H20), and to the nearest 1.3 mm HgO
(0.05 in. H20) for Ap values above 25 mm H20 (1.0 in. H20). A special, more
sensitive gauge will be required to read Ap values below 1.3 mm H20 [0.05
in. H20](see Citation 18 in Section 6).
-------
1-22
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-------
1-23
3. Procedure
3.1 Set up the apparatus as shown in Figure 2-1. Capillary
tubing or surge tanks installed between the manometer and pitot tube
may be used to dampen Ap fluctuations. It is recommended, but not
required, that a pretest leak-check be conducted, as follows: (1) blow
through the pitot impact opening until at least 7.6 cm (3 in.)
HpO velocity pressure registers on the manometer; then, close off the
impact opening. The pressure shall remain stable for at least 15
seconds; (2) do the same for the static .pressure side, except using
suction to obtain the minimum of 7.6 cm (3 in.) H?0. Other leak-check
procedures, subject to the approval of the Administrator, may be used.
3.2 Level and zero the manometer. Because the manometer level
and zero may drift due to vibrations and temperature changes, make
periodic checks during the traverse. Record all necessary data as
shown in the example data sheet (Figure 2-5).
3.3 Measure the velocity head and temperature at the traverse
points specified by Method 1. Ensure that the proper differential
pressure gauge is being used for the range of Ap values encountered
(see Section 2.2). If it is necessary to change to a more sensitive
gauge, do so, and remeasure the Ap and temperature readings at each
traverse point. Conduct a post-test leak-check (mandatory), as
described in Section 3.1 above, to validate the traverse run.
3.4 Measure the static pressure in the stack. One reading is
usually adequate.
3.5 Determine the atmospheric pressure.
3.6 Determine the stack gas dry molecular weight. For combustion
processes or processes that emit essentially C02, 02» CO, and N2> use
-------
1-24
PLANT
DATE .
RUN NO.
STACK DIAMETER OR DIMENSIONS, m(m.)
BAROMETRIC PRESSURE, mm Hg (in. Hg)
CROSS SECTIONAL AREA, m2(ft2)
OPERATORS
PITOTTUBEI.D.NO.
AVG. COEFFICIENT, Cp =
LAST DATE CALIBRATED.
SCHEMATIC OF STACK
CROSS SECTION
Traverse
Pt. No.
Vel. Hd.,Ap
mm (in.) H20
Stack Temperature
ts, °C
mm Hg (in.Hg)
Average
Figure 2-5. Velocity traverse data.
-------
1-25
Method 3. For processes emitting essentially air, an analysis need
not be conducted; use a dry molecular weight of 29.0. For other processes,
other methods, subject to the approval of the Administrator, must be used.
3.7 Obtain the moisture content from Reference Method 4 (or
equivalent.) or from Method 5.
3.8 Determine the cross-sectional area of the stack or duct at
the sampling location. Whenever possible, physically measure the stack
dimensions rather than using blueprints.
4. Calibration
4.1 Type S Pi tot Tube. Before its initial use, carefully examine
the Type S pitot tube in top, side, and end views to verify that the face
openings of the tube are aligned within the specifications illustrated in
Figure 2-2 or 2-3. The pitot tube shall not be used if it fails to meet
these alignment specifications.
After verifying the face opening alignment, measure and record the
following dimensions of the pitot tube: (a) the external tubing diameter
(dimension D., Figure 2-2b); and (b) the base-to-opening plane distances
(dimensions P. and Pg, Figure 2-2b). If D. is between 0.48 and 0.95 cm
(3/16 and 3/8 in.), and if P. and Pg are equal and between 1.05 and 1.50
D., there are two possible options: (1) the pitot tube may be cali-
brated according to the procedure outlined in Sections 4.1.2 through
4.1.5 below, or (2) a baseline (isolated tube) coefficient value of
0.84 may be assigned to the pitot tube. Note, however, that if the
pitot tube is part of an assembly, calibration may still be required,
despite knowledge of the baseline coefficient value (see Section 4.1.1).
If Dt, PA, and PB are outside the specified limits, the pitot tube
must be calibrated as outlined in 4.1.2 through 4.1.5 below.
-------
1-26
4.1.1 Type S Pitot Tube Assemblies. During sample and velocity
traverses, the isolated Type S pi tot tube is not always used; in many
instances, the pi tot tube is used in combination with other source-
sampling components (thermocouple, sampling probe, nozzle) as part
of an "assembly." The presence of other sampling components can
sometimes affect the baseline value of the Type S pitot tube
coefficient (Citation 9 in Section 6); therefore an assigned (or
otherwise known) baseline coefficient value may or may not be valid
for a given assembly. The baseline an^ assembly coefficient values
will be identical only when the relative placement of the components
in the assembly is such that aerodynamic interference effects are
eliminated. Figures 2-6 through 2-8 illustrate interference-free
component arrangements for Type S pitot tubes having external tubing
diameters between 0.48 and 0.95 cm (3/16 and 3/8 in.). Type S pitot
tube assemblies that fail to meet any or all of the specifications of
Figures 2-6 through 2-8 shall be calibrated according to the procedure
outlined in Sections 4.1.2 through 4.1.5 below, and prior to calibra-
tion, the values of the intercomponent spacings (pitot-nozzle, pitot-
thermocouple, pitot-probe sheath) shall be measured and recorded.
Note: Do not use any Type S pitot tube assembly which is
constructed such that the impact pressure opening plane of the pitot
tube is below the entry plane of the nozzle (see Figure 2-6b).
4.1.2 Calibration Setup. If the Type S pitot tube is to be
calibrated, one leg of the tube shall be permanently marked A, and the
other, B. Calibration shall be done in a flow system having the follow-
ing essential design features:
4.1.2.1 The flowing gas stream must be confined to a duct of
definite cross-sectional area, either circular or rectangular. For
-------
1-27
TYPE SPITOT TUBE
i > 1.90 cm (3/4 in.) FOR Dn - 1.3 cm (1/2 in.)
SAMPLING NOZZLE
A. BOTTOM VIEW; SHOWING MINIMUM PITOT-NOZZLE SEPARATION.
SAMPLING
PROBE
\
SAMPLING
NOZZLE
TYPES
PITOTTUBE
NOZZLE ENTRY
PLANE
a SIDE VIEW; TO PREVENT PITOTTUBE
FROM INTERFERING WITH GAS FLOW
STREAMLINES APPROACHING THE
NOZZLE. THE IMPACT PRESSURE
OPENING PLANE OF THE PITOT TUBE
SHALL BE EVEN WITH OR ABOVE THE
NOZZLE ENTRY PLANE.
STATIC PRESSURE
OPENING PLANE
IMPACT PRESSURE
OPENING PLANE
Figure 2-6. Proper pitot tube - sampling nozzle configuration to prevent
aerodynamic interference; buttonhook - type nozzle; centers of nozzle
and pitot opening aligned; Dt between 0.48 and 0.95 cm (3/16 and
3/8 in.).
-------
1-28
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-------
1-30
circular cross-sections, the minimum duct diameter shall be 30.5 cm
(12 in.); for rectangular cross-sections, the width (shorter side)
shall be at least 25.4 cm (10 in.).
4.1.2.2 The cross-sectional area of the calibration duct must
be constant over a distance of 10 or more duct diameters. For a
rectangular cross-section, use an equivalent diameter, calculated
from the following equation, to determine the number of duct diameters:
where:
De = TI Equation 2-1
D = Equivalent diameter
L = Length
W = Width
To ensure the presence of stable, fully developed flow patterns
at the calibration site, or "test section," the site must be located
at least eight diameters downstream and two diameters upstream from
the nearest disturbances.
Note: The eight- and two-diameter criteria are not absolute;
other test section locations may be used (subject to approval of the
Administrator), provided that the flow at the test site is stable and
demonstrably parallel to the duct axis.
4.1.2.3 The flow system shall have the capacity to generate a
test-section velocity around 915 m/min (3000 ft/min). This velocity
must be constant with time to guarantee steady flow during calibration.
Note that Type S pitot tube coefficients obtained by single-velocity
calibration at 915 m/min (3000 ft/min) will generally be valid to
within +3 percent for the measurement of velocities above 305 m/min
-------
1-31
(1000 ft/min) and to within +5 to 6 percent for the measurement of
velocities between 180 and 305 m/min (600 and 1000 ft/min). If a
more precise correlation between C and velocity is desired, the flow
system shall have the capacity to generate at least four distinct,
time-invariant test-section velocities covering the velocity range
from 180 to 1525 m/min (600 to 5000 ft/min), and calibration data
shall be taken at regular velocity intervals over this range (see
Citations 9 and 14 in Section 6 for details).
4.1.2.4 Two entry ports, one each for the standard and Type S
pitot tubes, shall be cut in the test section; the standard pitot entry
port shall be located slightly downstream of the Type S port, so that
the standard and Type S impact openings will lie in the same cross-
sectional plane during calibration. To facilitate alignment of the
pitot tubes during calibration, it is advisable that the test section
be constructed of plexiglas or some other transparent material.
4.1.3 Calibration Procedure. Note that this procedure is a
general one and must not be used without first referring to the special
considerations presented in Section 4.1.5. Note also that this pro-
cedure applies only to single-velocity calibration. To obtain calibration
data for the A and B sides of the Type S pitot tube, proceed as follows:
4.1.3.1 Make sure that the manometer is properly filled and that
the oil is free from contamination and is of the proper density. Inspect
and leak-check all pitot lines; repair or replace if necessary.
4.1.3.2 Level and zero the manometer. Turn on the fan and allow
the flow to stabilize. Seal the Type S entry port.
4.1.3.3 Ensure that the manometer is level and zeroed. Position
the standard pitot tube at the calibration point (determined as outlined
-------
1-32
in Section 4.1.5.1), and align the tube so that its tip is pointed
directly into the flow. Particular care should be taken in aligning
the tube to avoid yaw and pitch angles. Make sure that the entry
port surrounding the tube is properly sealed.
4.1.3.4 Read Apstd and record its value in a data table similar
to the one shown in Figure 2-9. Remove the standard pitot tube from
the duct and disconnect it from the manometer. Seal the standard
entry port.
4.1.3.5 Connect the Type S pitot tube to the manometer. Open
the Type S entry port. Check the manometer level and zero. Insert
and align the Type S pitot tube so that its A side impact opening is
at the same point :as was the standard pitot tube and is pointed directly
into the flow.. .Wake sure that the entry port surrounding the tube is
properly sealed.
4.1.3.6 Read Ap and enter its value in the data table. Remove
the Type S pitot tube from the duct and disconnect it from the manometer.
4.1.3.7 Repeat steps 4.1.3.3 through 4.1.3.6 above until three
pairs of Ap readings have been obtained.
4.1.3.8 Repeat steps 4.1.3.3 through 4.1.3.7 above for the B side
of the Type S pitot tube.
4.1.3.9 Perform calculations, as,: described in Section 4.1.4 below.
4.1.4 Calculations.
4.1.4.1 For each of the six pairs of Ap readings (i.e., three
from side A and three from side B) obtained in Section 4.1.3 above,
calculate the value of the Type S pitot tube coefficient as follows:
-------
1-33
PITOTTUBE IDENTIFICATION NUMBER:
CALIBRATED BY: .
DATE.
RUN NO.
1
2
3
"A" SIDE CALIBRATION
Apstd
cm H20
(in. H20)
AP(S)
cm H20
(in. H20)
Cp (SIDE A)
Cp(s)
DEVIATION
CP(S)-CP(A)
RUN NO.
1
2
3
"B"SIDE CALIBRATION
Apstd
cm H20
(in. H20)
AP(s)
cm H20
(in.H20)
Cp (SIDE B)
Cp($)
DEVIATION
Cp(s)-Cp(B)
I |Cp(s)-Cp(AORB)|
AVERAGE DEVIATION = o(AORB) =
MUSTBE<0.01
Cp (SIDE A)-Cp (SIDE B) |-«-MUST BE <0.01
Figure 29. Pitot tube calibration data.
-------
1-34
Cp(s) ' Cp(std) /-^ E«uat1on 2-
where:
C / \ = Type S pitot tube coefficient
C / ..N = Standard pitot tube coefficient; use 0.99 if the
coefficient is unknown and the tube is designed
according to the criteria of Sections 2.7.1 to 2.7.5
of this method.
Ap .. = Velocity head measured by the standard pitot tube,
cm H20 (in. H20)
Ap = Velocity head measured by the Type S pitot tube,
cm H20 (in. H20)
4.1.4.2 Calculate C~ (side A), the mean A-side coefficient, and
C_ (side B), the mean B-side coefficient; calculate the difference
between these two average values.
4.1.4.3 Calculate the deviation of each of the three A-side values
of C / i from C" (side A), and the deviation of each B-side value of
C , x from £" (side B). Use the following equation:
Deviation = C / » - C" (A or B) Equation 2-3
4.1.4.4 Calculate o, the average deviation from the mean, for
both the A and B sides of the pitot tube. Use the following equation:
\ lCp(s) ' S> (AorB)|
a (side A or B) = = Eauation 2-4
-------
1-35
4.1.4.5 Use the Type S pitot tube only if the values of o
(side A) and o (side B) are less than or equal to 0.01 and if the
absolute value of the difference between C_ (A) and C" (B) is 0.01
or less.
4.1.5 Special considerations.
4.1.5.1 Selection of calibration point.
4.1.5.1.1 When an isolated Type S pitot tube is calibrated,
select a calibration point at or near the center of the duct, and
follow the procedures outlined in Sections 4.1.3 and 4.1.4 above.
The Type S pitot coefficients so obtained, i.e., C (side A) and
C (side B), will be valid, so long as either: (1) the isolated
pitot tube is used; or (2) the pitot tube is used with other com-
ponents (nozzle, thermocouple, sample probe) in an arrangement that
is free from aerodynamic interference effects (see Figures 2-6 through
2-8).
4.1.5.1.2 For Type S pitot tube-thermocouple combinations
(without sample probe), select a calibration point at or near the
center of the duct, and follow the procedures outlined in Sections
4.1.3 and 4.1.4 above. The coefficients so obtained will be valid
so long as the pitot tube-thermocouple combination is used by itself
or with other components in an interference-free arrangement (Figures
2-6 and 2-8).
4.1.5.1.3 For assemblies with sample probes, the calibration
point should be located at or near the center of the duct; however,
-------
1-36
insertion of a probe sheath into a small duct may cause significant
cross-sectional area blockage and yield incorrect coefficient
values (Citation 9 in Section 6). Therefore, to minimize the
blockage effect, the calibration point may be a few inches off-center
if necessary. The actual blockage effect will be negligible when the
theoretical blockage, as determined by a projected-area model of the
probe sheath, is 2 percent or less of the duct cross-sectional area
for assemblies without external sheaths (Figure 2-10a), and 3 percent
or less for assemblies with external sheaths (Figure 2-10b).
4.1.5.2 For those probe assemblies in which pitot tube-nozzle
interference is a factor (i.e., those in which the pitot-nozzle
separation distance fails to meet the specification illustrated in
Figure 2-6a), the value of C / > depends upon the amount of free-space
between the tube and nozzle, and therefore is a function of nozzle
size. In these instances, separate calibrations shall be performed
with each of the commonly used nozzle sizes in place. Note that the
single-velocity calibration technique is acceptable for this purpose,
even though the larger nozzle sizes (>0.635 cm or 1/4 in.) are not
ordinarily used for isokinetic sampling at velocities around
915 m/min (3000 ft/min), which is the calibration velocity; note
also that it is not necessary to draw an isokinetic sample during
calibration (see Citation 19 in Section 6).
4.1.5.3 For a probe assembly constructed such that its pitot
tube is always used in the same orientation, only one side of the
pitot tube need be calibrated (the side which will face the flow).
The pitot tube must still meet the alignment specifications of
Figure'2-2 or 2-3, however, and must have an average deviation (a)
value of 0.01 or less (see Section 4.1.4.4).
-------
1-37
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1-38
4.1.6 Field Use and Recalibration.
4.1.6.1 Field Use.
4.1.6.1.1 When a Type S pitot tube (isolated tube or assembly) is
used in the field, the appropriate coefficient value (whether assigned
or obtained by calibration) shall be used to perform velocity calculations.
For calibrated Type S pitot tubes, the A side coefficient shall be used
when the A side of the tube faces the flow, and the B side coefficient
shall be used when the B side faces the flow; alternatively, the
arithmetic average of the A and B side coefficient values may be
used, irrespective of which side faces the flow.
4.1.6.1.2 When a probe assembly is used to sample a small duct
(12 to 36 in. in diameter), the probe sheath sometimes blocks a
significant part of the duct cross-section, causing a reduction in
the effective value of C"D(S)- Consult Citation 9 in Section 6 for
details. Conventional pitot-sampling probe assemblies are not recom-
mended for use in ducts having inside diameters smaller than 12 inches
(Citation 16 in Section 6).
4.1.6.2 Recalibration.
4.1.6.2.1 Isolated Pitot Tubes. After each field use, the pitot
tube shall be carefully reexamined in top, side, and end views. If the
pitot face openings are still aligned within the specifications illus-
trated in Figure 2-2 or 2-3, it can be assumed that the baseline coef-
ficient of the pitot tube has not changed. If, however, the tube has
been damaged to the extent that it no longer meets the specifications of
Figure 2-2 or 2-3, the damage shall either be repaired to restore
proper alignment of the face openings or the tube shall be discarded.
4.1.6.2.2 Pitot Tube Assemblies. After each field use, check the
face opening alignment of the pitot tube, as in Section 4.1.6.2.1; also,
-------
1-39
remeasure the intercomponent spacings of the assembly. If the inter-
component spacings have not changed and the face opening alignment is
acceptable, it can be assumed that the coefficient of the assembly
has not changed. If the face opening alignment is no longer within the
specifications of Figures 2-2 or 2-3, either repair the damage or
replace the pitot tube (calibrating the new assembly, if necessary).
If the intercomponent spacings have changed, restore the original
spacings or recalibrate the assembly.
4.2 Standard pitot tube (if applicable). If a standard pitot tube
is used for the velocity traverse, the tube shall be constructed
according to the criteria of Section 2.7 and shall be assigned a
baseline coefficient value of 0.99. If the standard pitot tube is
used as part of an assembly, the tube shall be in an interference-
free arrangement (subject to the approval of the Administrator).
4.3 Temperature Gauges. After each field use, calibrate dial
thermometers, liquid-filled bulb thermometers, thermocouple-
potentiometer systems, and othe^ gauges at a temperature within
10 percent of the average absolute stack temperature. For temperatures
up to 405°C (761°F), use an ASTM mercury-in-glass reference thermometer,
or equivalent, as a reference; alternatively, either a reference
thermocouple and potentiometer (calibrated by NBS) or thermometric
fixed points, e.g., ice bath and boiling water (corrected for barometric
pressure) may be used. For temperatures above 405°C (761°F), use an
NBS-calibrated reference thermocouple-potentiometer system or an
alternate reference, subject to the approval of the Administrator.
If, during calibration, the absolute temperatures measured with
the gauge being calibrated and the reference gauge agree within 1.5
percent, the temperature data taken in the field shall be considered
valid. Otherwise, the pollutant emission test shall either be
-------
1-40
considered invalid or adjustments (if appropriate) of the test results
shall be made, subject to the approval of the Administrator.
4.4 Barometer. Calibrate the barometer used against a mercury
barometer.
5. Calculations
Carry out calculations, retaining at least one extra decimal
figure beyond that of the acquired data. Round off figures after
final calculation.
5.1 Nomenclature.
2 2
A = Cross-sectional area of stack, m (ft ).
B = Water vapor in the gas stream (from Method 5 or Reference
ws
Method 4), proportion by volume.
C = Pitot tube coefficient, dimensionless.
K = Pitot tube constant,
Q7 m f(g/g-mo1e)(mm Hg)I
^'y/ sec" |_ (*K)(mm H20) J
1/2
:; yum nyj i
i H20) J
for the metric system and
PR 40 -It r(lb/1b-mole)(in. Hg)]
00"^ sec L (°R)(1n. H20) |
for the English system.
M. = Molecular weight of stack gas, dry basis (see Section 3.6)
g/g-mole (Ib/lb-mole).
M = Molecular weight of stack gas, wet basis, g/g-mole
(Ib/lb-mole).
= Md(l - Bws) + 18.0 Bws Equation 2-5
Pbar = Barometric pressure at measurement site, mm Hg (in. Hg).
P = Stack static pressure, mm Hg (in. Hg).
-------
1-41
P = Absolute stack gas pressure, mm Hg (in. Hg).
d
= Pbar * Pq Equation 2-6
Pstd = standard absolute pressure, 760 mm Hg (29.92 in. Hg).
Qsd = Dry volumetric stack gas flow rate corrected to standard
»
conditions, dscm/hr (dscf/hr).
t$ = Stack temperature, °C (°F).
TS = Absolute stack temperature, °K (°R).
= 273 + t for metric Equation 2-7
o
= 460 + t for English Equation 2-8
Tstd = standard absolute temperature, 293 °K (528°R).
v = Average stack gas velocity, m/sec (ft/sec).
Ap = Velocity head of stack gas, mm H20 (in. FLO).
3600 = Conversion factor, sec/hr.
18.0 = Molecular weight of water, g/g-mole (Ib/lb-mole).
5.2 Average stack gas velocity.
vs = KpCp (/ZF) Equation 2-9
5.3 Average stack gas dry volumetric flow rate.
Qsd = 3600 (1-B ) v A L std ) (p-S-l Equation 2-10
S WS S Vs(aVg)y \pstd/
8. Bibliography
1. Mark, L. S. Mechanical Engineers' Handbook. New York.
McGraw-Hill Book Co., Inc. 1951.
2. Perry, 0. H. Chemical Engineers' Handbook. New York
McGraw-Hill Book Co., Inc. 1960.
-------
1-42
3. Shigehara, R. T., W. F. Todd, and W. 5. Smith. Significance
of Errors in Stack Sampling Measurements. U. S. Environmental
Protection Agency, Research Triangle Park, N. C. (Presented at the
Annual Meeting of the Air Pollution Control Association, St. Louis, Mo.,
June 14-19, 1970.)
4. Standard Method for Sampling Stacks for Particulate Matter.
In: 1971 Book of ASTM Standards, Part 23. Philadelphia, Pa. 1971.
ASTM Designation D-2928-71.
5. Vennard, J. K. Elementary Fluid Mechanics. New York.
John Wiley and Sons, Inc. 1947.
6. Fluid Meters - Their Theory and Application. American Society
of Mechanical Engineers, New York, N.Y. 1959.
7. ASHRAE Handbook of Fundamentals. 1972. p. 208.
8. Annual Book of ASTM Standards, Part 26. 1974. p. 648.
9. Vollaro, R. F. Guidelines for Type S Pitot Tube Calibration.
U. S. Environmental Protection Agency, Research Triangle Park, N. C.
(Presented at 1st Annual Meeting, Source Evaluation Society, Dayton, Ohio,
September 18, 1975.)
10. Vollaro, R. F. A Type S Pitot Tube Calibration Study. U. S.
Environmental Protection Agency, Emission Measurement Branch, Research
Triangle Park, N. C. July 1974.
11. Vollaro, R. F. The Effects of Impact Opening Misalignment on
the Value of the Type S Pitot Tube Coefficient. U. S. Environmental
Protection Agency, Emission Measurement Branch, Research Triangle Park,
N. C. October 1976.
-------
1-43
12. Vollaro, R. F. Establishment of a Baseline Coefficient Value
for Properly Constructed Type S Pi tot Tubes. U. S. Environmental
Protection Agency, Emission Measurement Branch, Research Triangle
Park, N. C. November 1976.
13. Vollaro, R. F. An Evaluation of Single-Velocity Calibration
Technique as a Means of Determining Type S Pitot Tube Coefficients.
U. S. Environmental Protection Agency, Emission Measurement Branch,
Research Triangle Park, N. C. August 1975.
14. Vollaro, R. F. The Use of Type S Pitot Tubes for the Measurement
of Low Velocities. U. S. Environmental Protection Agency, Emission
Measurement Branch, Research Triangle Park, N. C. November 1976.
15. Smith, Marvin L. Velocity Calibration of EPA Type Source
Sampling Probe. United Technologies Corporation, Pratt and Whitney
Aircraft Division, East Hartford, Conn. 1975.
16. Vollaro, R. F. Recommended Procedure for Sample Traverses in
Ducts Smaller than 12 Inches in Diameter. U. S. Environmental Protection
Agency, Emission Measurement Branch, Research Triangle Park, N. C.
November 1976.
17. Ower, E. and R. C. Pankhurst. The Measurement of Air Flow,
4th Ed. London, Pergamon Press. 1966.
18. Vollaro, R. F. A Survey of Commercially Available Instrumentation
for the Measurement of Low-Range Gas Velocities. U. S. Environmental
Protection Agency, Emission Measurement Branch, Research Triangle Park,
N. C. November 1976. (Unpublished Paper)
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1-44
19. Gnyp, A. W., C. C. St. Pierre, D. S. Smith, D. Mozzon, and
J. Steiner. An Experimental Investigation of the Effect of Pi tot Tube-
Sampling Probe Configurations on the Magnitude of the S Type Pitot Tube
Coefficient for Commercially Available Source Sampling Probes. Prepared
by the University of Windsor for the Ministry of the Environment,
Toronto, Canada. February 1975.
-------
GAS ANALYSIS FOR CARBON DIOXIDE, EXCESS AIR,
AND DRY MOLECULAR WEIGHT
METHODS
-------
1-45
METHOD 3--GAS ANALYSIS FOR CARBON DIOXIDE, OXYGEN,
EXCESS AIR, AND DRY MOLECULAR WEIGHT
1. Principle and Applicability
1.1 Principle. A gas sample is extracted from a stack, by one
of the following methods: (1) single-point, grab sampling; (2) single-
point, integrated sampling; or (3) multi-point, integrated sampling.
The gas sample is analyzed for percent carbon dioxide (C02), percent
oxygen (02), and, if necessary, percent carbon monoxide (CO). If a
dry molecular weight determination is to be made, either an Orsat
or a Fyrite analyzer may be used for the analysis; for excess air
or emission rate correction factor determination, an Orsat analyzer
must be used.
1.2 Applicability. This method is applicable for determining
C02 and 02 concentrations, excess air, and dry molecular weight of
a sample from a gas stream of a fossil-fuel combustion process. The
method may also be applicable to other processes where it has been
determined that compounds other than CO^, 02> CO, and nitrogen (N2)
are not present in concentrations sufficient to affect the results.
Other methods, as well as modifications to the procedure
described herein, are also applicable for some or all of the above
determinations. Examples of specific methods and modifications
include: (1) a multi-point sampling method using an Orsat analyzer
to analyze individual grab samples obtained at each point; (2) a
method using C02 or 02 and stoichiometric calculations to determine
dry molecular weight and excess air; (3) assigning a value of 30.0
Mention of trade names or specific products does not constitute
endorsement by the Environmental Protection Agency.
-------
1-46
for dry molecular weight, in lieu of actual measurements, for
processes burning natural gas, coal, or oil. These methods and
modifications may be used, but are subject to the approval of the
Administrator, U.S. Environmental Protection Agency.
2. Apparatus
As an alternative to the sampling apparatus and systems described
herein, other sampling systems (e.g., liquid displacement) may be
used provided such systems are capable of obtaining a representative
sample and maintaining a constant sampling rate, and are otherwise
capable of yielding acceptable results. Use of such systems is
subject to the approval of the Administrator.
2.1 Grab Sampling (Figure 3-1).
2.1.1 Probe. The probe should be made of stainless steel or
borosilicate glass tubing and should be equipped with an in-stack
or out-stack filter to remove particulate matter (a plug of glass
*wool is satisfactory for this purpose). Any other material inert to
CL, CCL, CO, and N« and resistant to temperature at sampling conditions
may be used for the probe; examples of such material are aluminum,
copper, quartz glass and Teflon.
2.1.2 Pump. A one-way squeeze bulb, or equivalent, is used
to transport the gas sample to the analyzer.
2.2 Integrated Sampling (Figure 3-2).
2.2.1 Probe. A probe such as that described in Section 2.1.1
is suitable.
-------
1-47
PROBE
FLEXIBLE TUBING
FILTER (GLASS WOOL)
SQUEEZE BULB
TO ANALYZER
Figure 3-1. Grab sampling train.
RATE METER
AIR-COOLED
CONDENSER
PROBE
\
FILTER
(GLASS WOOL)
QUICK DISCONNECT
J-l
RIGID CONTAINER
Figure 3-2. Integrated gas-sampling train.
-------
1-48
2.2.2 Condenser. An air-cooled or water-cooled condenser,
or other condenser that will not remove 02, C02, CO, and N2, may
be used to remove excess moisture which would interfere with
the operation of the pump and flow meter.
2.2.3 Valve. A needle valve is used to adjust sample gas
flow rate.
2.2.4 Pump. A leak-free, diaphragm-type pump, or equivalent,
is used to transport sample gas to the flexible bag. Install a
small surge tank between the pump and rate meter to eliminate the
pulsation effect of the diaphragm pump on the rotameter.
2.2.5 Rate Meter. The rotameter, or equivalent rate meter,
used should be capable of measuring flow rate to within +2 percent
of the selected flow rate. A flow rate range of 500 to 1000
cm /nrin is suggested.
2.2.6 Flexible Bag. Any leak-free plastic (e.g., Tedlar,
Mylar, Teflon) or plastic-coated aluminum (e.g., aluminized
Mylar) bag, or equivalent, having a capacity consistent with the
selected flow rate and time length of the test run, may be used. A
capacity in the range of 55 to 90 liters is suggested.
To leak-check the bag, connect it to a water manometer and pressurize
the bag to 5 to 10 cm H20 (2 to 4 in. HJ)). Allow to stand for 10
minutes. Any displacement in the water manometer indicates a
leak. An alternative leak-check method is to pressurize the bag
to 5 to 10 cm H20 (2 to 4 in. H20) and allow to stand overnight. A
deflated bag indicates a leak.
-------
1-49
2.2.7 Pressure Gauge. A water-filled U-tube manometer, or
equivalent, of about 28 cm (12 in.) is used for the flexible bag
leak-check.
2.2.8 Vacuum Gauge. A mercury manometer, or equivalent, of at
least 760 mm Hg (30 in. Hg) is used for the sampling train leak-check.
2.3 Analysis. For Orsat and Fyrite analyzer maintenance and
operation procedures, follow the instructions recommended by the
manufacturer, unless otherwise specified herein.
2.3.1 Dry Molecular Weight Determination. An Orsat analyzer or
Fyrite type combustion gas analyzer may be used.
2.3.2 Emission Rate Correction Factor or Excess Air Determination.
An Orsat analyzer must be used. For low (XL (less than 4.0 percent)
or high Op (greater than 15.0 percent) concentrations, the measuring
burette of the Orsat must have at least 0.1 percent subdivisions.
3. Dry Molecular Weight Determination
Any of the three sampling and analytical procedures described
below may be used for determining the dry molecular weight.
3.1 Single-Point, Grab Sampling and Analytical Procedure.
3.1.1 The sampling point in the duct shall either be at the
centroid of the cross section or at a point no closer to the walls
than 1.00 m (3.3 ft), unless otherwise specified by the Administrator.
3.1.2 Set up the equipment as shown in Figure 3-1, making sure
all connections ahead of the analyzer are tight and leak-free. If an
Orsat analyzer is used, it is recommended that the analyzer be leak-
checked by following the procedure in Section 5; however, the leak-
check is optional.
-------
1-50
3.1.3 Place the probe in the stack, with the tip of the probe
positioned at the sampling point; purge the sampling line. Draw a
sample into the analyzer and immediately analyze it for percent C0?
and percent 0_. Determine the percentage of the gas that is N2 and
CO by subtracting the sum of the percent CO. and percent 0? from
100 pet ;nt. Calculate the dry molecular weight as indicated in
Section 6.3.
3.1.4 Repeat the sampling, analysis, and calculation procedures,
until the dry molecular weights of any three grab samples differ from
their mean by no more than 0.3 g/g-mole (0.3 Ib/lb-mole). Average
these three molecular weights, and report the results to the nearest
0.1 g/g-mole (Ib/lb-mole).
3.2 Single-Point, Integrated Sampling and Analytical Procedure.
3.2.1 The sampling point in the duct shall be located as speci-
fied in Section 3.1.1.
3.2.2 Leak-check (optional) the flexible bag as in Section 2.2.6.
Set up the equipment as shown in Figure 3-2. Just prior to sampling,
leak-check (optional) the train by placing a vacuum gauge at the
condenser inlet, pulling a vacuum of at least 250 mm Hg (10 in. Hg),
plugging the outlet at the quick disconnect, and then turning off the
pump. The vacuum should remain stable for at least 0.5 minute.
Evacuate the flexible bag. Connect the probe and place it in the
stack, with the tip of the probe positioned at the sampling point;
purge the sampling line. Next, connect the bag and make sure that
all connections are tight and leak free.
-------
1-51
3.2.3 Sample at a constant rate. The sampling run should be
simultaneous with, and for the same total length of time as, the
pollutant emission rate determination. Collection of at least 30
o
liters (1.00 ft ) of sample gas is recommended; however, smaller
volumes may be collected, if desired.
3.2.4 Obtain one integrated flue gas sample during each pollutant
emission rate determination. Within 8 hours after the sample is taken,
analyze it for percent COp and percent 0,, using either an Orsat
analyzer or a Fyrite type combustion gas analyzer. If an Orsat
analyzer is used, it is recommended that the Orsat leak-check
described in Section 5 be performed before this determination;
however, the check is optional. Determine the percentage of the
gas that is Np and CO by subtracting the sum of the percent COp and
percent 02 from 100 percent. Calculate the dry molecular weight as
indicated in Section 6.3.
3.2.5 Repeat the analysis and calculation procedures until the
individual dry molecular weights for any three analyses differ from
their mean by no more than 0.3 g/g-mole (0.3 Ib/lb-mole). Average
these three molecular weights, and report the results to the nearest
0.1 g/g-mole (0.1 Ib/lb-mole).
3.3. Multi-Point, Integrated Sampling and Analytical Procedure.
3.3.1 Unless otherwise specified by the Administrator, EPA, a
minimum of eight traverse points shall be used for circular stacks having
diameters less than 0.61 m (24 in.), a minimum of nine shall be used for
rectangular stacks having equivalent diameters less than 0.61 m (24 in.),
and a minimum of twelve traverse points shall be used for all other
cases. The traverse points shall be located according to Method 1. The
use of fewer points is subject to the approval of the Administrator.
-------
1-52
3.3.2 Follow the procedures outlined in Sections 3.2.2
through 3.2.5, except for the following: traverse all sampling
points and sample at each point for an equal length of time.
Record sampling data as shown in Figure 3-3.
4. Emission Rate Correction Factor or Excess Air Determination
Note: A Fyrite type combustion gas analyzer is not acceptable
or excess air or emission rate correction factor determination,
unless approved by the Administrator, If both percent C02 and
percent CL are measured, the analytical results of any of the three
procedures given below may also be used for calculating the dry
molecular weight.
Each of the three procedures below shall be used only when
specified in an applicable subpart of the standards. The use of
these procedures for other purposes must have specific prior approval
of the Administrator.
4.1 Single-Point, Grab Sampling and Analytical Procedure.
4.1.1 The sampling point in the duct shall either be at the
centroid of the cross-section or at a point no closer to the walls
than 1.00 m (3.3 ft), unless otherwise specified by the Administrator.
4.1.2 Set up the equipment as shown in Figure 3-1, making sure
all connections ahead of the analyzer are tight and leak-free. Leak-
check the Orsat analyzer according to the procedure described in
Section 5. This leak-check is mandatory.
4.1.3 Place the probe in the stack, with the tip of the probe
positioned at the sampling point; purge the sampling line. Draw
-------
1-53
TIME
TRAVERSE
PT.
AVERAGE
Q
1pm
% DEV.a
a
%DEV=
(MUST BE < 10%)
Figure 3-3. Sampling rate data.
-------
1-54
a sample into the analyzer. For emission rate correction factor
determination, immediately analyze the sample, as outlined in Sections
4.1.4 and 4.1.5, for percent C0? or percent 02. If excess air is
desired, proceed as follows: (1) immediately analyze the sample, as in
Sections 4.1.4 and 4.1.5, for percent CO,,, 02, and CO; (2) determine the
percentage of the gas that is Np by subtracting the sum of the percent
C02, percent 0,,, and percent CO from 100 percent; and (3) calculate
percent excess air as outlined in Section 6.2.
4.1.4 To ensure complete absorption of the C02, 0^, or if appli-
cable, CO, make repeated passes through each absorbing solution until
two consecutive readings are the same. Several passes (three or four)
should be made between readings. (If constant readings cannot be
obtained after three consecutive readings, replace the absorbing solution.)
4.1.5 After the analysis is completed, leak-check (mandatory)
the Orsat analyzer once again, as described in Section 5. For the
results of the analysis to be valid, the Orsat analyzer must pass
this leak test before and after the analysis. Note: Since this
single-point, grab sampling and analytical procedure is normally
conducted in conjunction with a single-point, grab sampling and
analytical procedure for a pollutant, only one analysis is ordinarily
conducted. Therefore, great care must be taken to obtain a valid
sample and analysis. Although in most cases only C02 or 0? is
required, it is recommended that both C02 and 02 be measured, and
that Citation 5 in the Bibliography be used to validate the analytical
data.
-------
1-55
4.2 Single-Point, Integrated Sampling and Analytical Procedure.
.2.1 The sampling point in the duct shall be located as
specified in Section 4.1.1.
4.2.2 Leak-check (mandatory) the flexible bag as in Section 2.2.6.
Set up the equipment as shown in Figure 3-2. Just prior to sampling,
leak-check (mandatory) the train by placing a vacuum gauge at the
condenser inlet, pulling a vacuum of at least 250 mm Hg (10 in. Hg),
plugging the outlet at the quick disconnect, and then turning off the
pump. The vacuum shall remain stable for at least 0.5 minute.
Evacuate the flexible bag. Connect the probe and place it in the
stack, with the tip of the probe positioned at the sampling point;
purge the sampling line. Next, connect the bag and make sure that all
connections are tight and leak free.
4.2.3 Sample at a constant rate, or as specified by the
Administrator. The sampling run must be simultaneous with, and for
the same total length of time as, the pollutant emission rate
o
determination. Collect at least 30 liters (1.00 ft ) of sample
gas. Smaller volumes may be collected, subject to approval of the
Administrator.
4.2.4 Obtain one integrated flue gas sample during each pollutant
emission rate determination. For emission rate correction factor
determination, analyze the sample within 4 hours after it is taken
for percent CO^ or percent 0^ (as outlined in Sections 4.2.5 through
4.2.7). The Orsat analyzer must be leak-checked (see Section 5) before
the analysis. If excess air is desired, proceed as follows: (1) within
4 hours after the sample is taken, analyze it (as in Sections 4.2.5
-------
1-56
through 4.2.7) for percent C02, 0^, and CO; (2) determine the percentage
of the gas that is ^ by subtracting the sum of the percent CO.,, percent
Op, and percent CO from 100 percent; (3) calculate percent excess air,
as outlined in Section 6.2.
4.2.5 To ensure complete absorption of the COp, Op, or if applicable,
CO, make repeated passes through each absorbing solution until two
consecutive readings are the same. Several passes (three or four)
should be made between readings. (If constant readings cannot be obtained
after three consecutive readings, replace the absorbing solution.)
4.2.6 Repeat the analysis until the following criteria are met:
4.2.6.1 For percent COp, repeat the analytical procedure until the
results of any three analyses differ by no more than (a) 0.3 percent by
volume when COp is greater than 4.0 percent or (b) 0.2 percent by volume
when COp is less than or equal to 4.0 percent. Average the three acceptable
values of percent COp and report the results tu the nearest 0.1 percent.
4.2.6.2 For percent Op, repeat the analytical procedure until the
results of any three analyses differ by no more than (a) 0.3 percent by
volume when D£ is less than 15.0 percent or (b) 0.2 percent by volume
when Op is greater than or equal to 15.0 percent. Average the three
acceptable values of percent Op and report the results to the nearest
0.1 percent.
4.2.6.3 For percent CO, repeat the analytical procedure until the
results of any three analyses differ by no more than 0.3 percent.
Average the three acceptable values of percent CC and report the results
to the nearest 0.1 percent.
-------
1-57
4.2.7 After the analysis is completed, leak-check (mandatory)
the Orsat analyzer once again, as described in Section 5. For the
results of the analysis to be valid, the Orsat analyzer must pass
this leak test before and after the analysis. Note: Although in
most instances only CCL or 0. is required, it is recommended that
both C0? and CL be measured, and that Citation 5 in the Bibliography
be used to validate the analytical data.
4.3 Multi-Point, Integrated Sampling and Analytical Procedure.
4.3.1 Both the minimum number of sampling points and the
sampling point location shall be as specified in Section 3.3.1 of
this method. The use of fewer points than specified is subject to
the approval of the Administrator.
4.3.2 Follow the procedures outlined in Sections 4.2.2 through
4.2.7, except for the following: Traverse all sampling points and
sample at each point for an equal length of time. Record sampling
data as shown in Figure 3-3.
5. Leak-Check Procedure for Orsat Analyzers
Moving an Orsat analyzer frequently causes it to leak. Therefore,
an Orsat analyzer should be thoroughly leak-checked on site before the
flue gas sample is introduced into it. The procedure for leak-checking
an Orsat analyzer is:
5.1.1 Bring the liquid level in each pipette up to the reference
mark on the capillary tubing and then close the pipette stopcock.
5.1.2 Raise the leveling bulb sufficiently to bring the confining
liquid meniscus onto the graduated portion of the burette and then
close the manifold stopcock.
-------
1-58
5.1.3 Record the meniscus position.
5.1.4 Observe the meniscus in the burette and the liquid level
in the pipette for movement over the next 4 minutes.
5.1.5 For the Orsat analyzer to pass the leak-check, two
conditions must be met:
5.1.5.1 The liquid level in each pipette must not fall below
the bottom of the capillary tubing during this 4-mini/te interval.
5.1.5.2 The meniscus in the burette must not change by more
than 0.2 ml during this 4-minute interval.
5.1.6 If the analyzer fails the leak-check procedure, all
rubber connections and stopcocks should be checked until the cause
of the leak is identified. Leaking stopcocks must be disassembled,
cleaned, and regreased. Leaking rubber connections must be replaced.
After the analyzer is reassembled, the leak-check procedure must be
repeated.
6. Calculations
6.1 Nomenclature.
M, = Dry molecular weight, g/g-mole (Ib/lb-mole).
%EA = Percent excess air.
%COp = Percent CO^ by volume (dry basis).
%0? = Percent 00 by volume (dry basis).
%CO = Percent CO by volume (dry basis).
%N? = Percent N? by volume (dry basis).
0.264 = Ratio of 02 to N2 in air, v/v.
-------
1-59
0.280 = Molecular weight of N2 or CO, divided by 100.
0.320 = Molecular weight of Op divided by 100.
0.440 = Molecular weight of COp divided by 100.
6.2 Percent Excess Air. Calculate the percent excess air (if
applicable), by substituting the appropriate values of percent Op,
CO, and N~ (obtained from Section 4.1.3 or 4.2.4) into Equation 3-1.
%EA =
- 0.5% CO
100 Equation 3-1
0.264 %N2 - (%02 - 0.5% CO)
_» .MH
Note: The equation above assumes that ambient air is used as
the source of Op and that the fuel does not contain appreciable
amounts of Np (as do coke oven or blast furnace gases). For those
cases when appreciable amounts of Np are present (coal, oil, and
natural gas do not contain appreciable amounts of Np) or when oxygen
enrichment is used, alternate methods, subject to approval of the
Administrator, are required.
6.3 Dry Molecular Weight. Use Equation 3-2 to calculate the
dry molecular weight of the stack gas.
Md = 0.440(%C02) + 0.320(%02) + 0.280(%N2 + %CO) Equation 3-2
Note: The above equation does not consider argon in air (about
0.9 percent, molecular weight of 37.7). A negative error of about
0.4 percent is introduced. The tester may opt to include argon in
the analysis using procedures subject to approval of the Administrator.
-------
1-60
7. Bibliography
1. Altshuller, A.P. Storage of Gases and Vapors in Plastic
Bags. International Journal of Air and Water Pollution. 6_:75-81.
1963.
2. Conner, William D. and J. S. Nader. Air Sampling with Plastic
Bags. Journal of the American Industrial Hygiene Association.
25_:291-297. 1964.
3. Burrell Manual for Gas Analysts, Seventh edition. Burrell
Corporation, 2223 Fifth Avenue, Pittsburgh, Pa. 15219. 1951.
4. Mitchell, W.J. and M.R. Midgett. Field Reliability of the
Orsat Analyzer. Journal of Air Pollution Control Association.
26:491-495. May 1976.
5. Shigehara, R.T., R.M. Neulicht, and W.S. Smith. Validating
Orsat Analysis Data from Fossil Fuel-Fired Units. Stack Sampling
News. 4(2):21-26. August, 1976.
-------
DETERMINATION OF MOISTURE IN STACK GASES
METHOD 4
-------
1-61
METHOD ADETERMINATION OF MOISTURE CONTENT
IN STACK GASES
1. Principle and Applicability
1.1 Principle. A gas sample is extracted at a constant rate from
the source; moisture is removed from the sample stream and determined
either volumetrically or gravimetrically.
1.2 Applicability. This method is applicable for determining the
moisture content of stack gas.
Two procedures are given. The first is a reference method, for
accurate determinations of moisture content (such as are needed to
calculate emission data). The second is an approximation method, which
provides estimates of percent moisture to aid in setting isokinetic
sampling rates prior to a pollutant emission measurement run. The
approximation method described herein is only a suggested approach;
alternative means for approximating the moisture content, e.g., drying
tubes, wet bulb-dry bulb techniques, condensation techniques, stoichio-
metric calculations, previous experience, etc., are also acceptable.
The reference method is often conducted simultaneously with
a pollutant emission measurement run; when it is, calculation of percent
isokinetic, pollutant emission rate, etc., for the run shall be based upon
the results of the reference method or its equivalent; these calculations
shall not be based upon the results of the approximation method, unless
the approximation method is shown, to the satisfaction of the Administrator,
U. S. Environmental Protection Agency, to be capable of yielding results
within 1 percent HpO of the reference method.
-------
1-62
Note: The reference method may yield questionable results
when applied to saturated gas streams or to streams that contain
water droplets. Therefore, when these conditions exist or are
suspected, a second determination of the moisture content shall
be made simultaneously with the reference method, as follows: Assume
that the gas stream is saturated. Attach a temperature sensor [capable
of measuring to + 1° C (2° F)] to the reference method probe. Measure
the stack gas temperature at each traverse point (see Section 2.2.1)
during the reference method traverse; calculate the average stack gas
temperature. Next, determine the moisture percentage, either by:
(1) using a psychrometric chart and making appropriate corrections if
stack pressure is different from that of the chart, or (2) using
saturation vapor pressure tables. In cases where the psychrometric
chart or the saturation vapor pressure tables are not applicable (based
on evaluation of the process), alternate methods, subject to the approval
of the Administrator, shall be used.
2. Reference Method
The procedure described in Method 5 for determining moisture
content is acceptable as a reference method.
2.1 Apparatus. A schematic of the sampling train used in
this reference method is shown in Figure 4-1. All components
shall be maintained and calibrated according to the procedure
outlined in Method 5.
2.1.1 Probe. The probe is constructed of stainless steel or
glass tubing, sufficiently heated to prevent water condensation, and
is equipped with a filter, either in-stack (e.g., a plug of glass
-------
1-63
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1-64
wool inserted into the end of the probe) or heated out-stack (e.g.,
as described in Method 5), to remove participate matter.
When stack conditions permit, other metals or plastic tubing
may be used for the probe, subject to the approval of the
Administrator.
2.1.2 Condenser. The condenser consists of four impingers
connected in series with ground glass, leak-free fittings or any
similarly leak-free non-contaminating fittings. The first, third, and
fourth impingers shall be of the Greenburg-Smith design, modified
by replacing the tip with a 1.3 centimeter (1/2 inch) ID glass tube
extending to about 1.3 cm (1/2 in.) from the bottom of the flask.
The second impinger shall be of the Greenburg-Smith design with the
standard tip. Modifications (e.g., using flexible connections
between the impingers, using materials other than glass, or using
flexible vacuum lines to connect the filter holder to the condenser)
may be used, subject to the approval of the Administrator.
The first two impingers shall contain known volumes of water,
the third shall be empty, and the fourth shall contain a known
weight of 6- to 16-mesh indicating type silica gel, or equivalent
desiccant. If the silica gel has been previously used, dry at
175°C (350°F) for 2 hours. New silica gel may be used as received.
A thermometer, capable of measuring temperature to within 1°C
(2°F), shall be placed at the outlet of the fourth impinger, for
monitoring purposes.
Alternatively, any system may be used (subject to the approval
of the Administrator) that cools the sample gas stream and allows
-------
1-65
measurement of both the water that has been condensed and the
moisture leaving the condenser, each to within 1 ml or 1 g.
Acceptable means are to measure the condensed water, either gravi-
metrically or volumetrically, and to measure the moisture leaving
the condenser by: (1) monitoring the temperature and pressure at
the exit of the condenser and using Dalton's law of partial pressures,
or (2) passing the sample gas stream through a tared silica gel (or
equivalent desiccant) trap, with exit gases kept below 20°C (68°F), and
determining the weight gain.
If means other than silica gel are used to determine the amount of
moisture leaving the condenser, it is recommended that silica gel (or
equivalent) still be used between the condenser system and pump, to
prevent moisture condensation in the pump and metering devices and to
avoid the need to make corrections for moisture in the metered volume.
2.1.3 Cooling System. An ice bath container and crushed ice
(or equivalent) are used to aid in condensing moisture.
2.1.4 Metering System. This system includes a vacuum gauge,
leak-free pump, thermometers capable of measuring temperature to
within 3°C (5.4°F), dry gas meter capable of measuring volume to
within 2 percent, and related equipment as shown in Figure 4-1.
Other metering systems, capable of maintaining a constant sampling
rate and determining sample gas volume, may be used, subject to the
approval of the Administrator.
2.1.5 Barometer. Mercury, aneroid, or other barometer
capable of measuring atmospheric pressure to within 2.5 mm Hg (0.1
in. Hg) may be used. In many cases, the barometric reading may be
obtained from a nearby national weather service station, in which
-------
1-66
case the station value (which is the absolute barometric pressure)
shall be requested and an adjustment for elevation differences
between the weather station and the sampling point shall be applied
at a rate of minus 2.5 mm Hg (0.1 in. Hg) per 30 m (100 ft) eleva-
tion increase or vice versa for elevation decrease.
2.1.6 Graduated Cylinder and/or Balance. These items are
used to measure condensed water and moisture caught in the silica
gel to within 1 ml or 0.5 g. Graduated cylinders shall have
subdivisions no greater than 2 ml. Most laboratory balances are
capable of weighing to the nearest 0.5 g or less. These balances
are suitable for use here.
2.2 Procedure. The following procedure is written for a
condenser system (such as the impinger system described in Section
2.1.2) incorporating volumetric analysis to measure the condensed
moisture, and silica gel and gravimetric analysis to measure the
moisture leaving the condenser.
2.2.1 Unless otherwise specified by the Administrator, a minimum of
eight traverse points shall be used for circular stacks having diameters
less than 0.61 m (24 in.), a minimum of nine points shall be used for
rectangular stacks having equivalent diameters less than 0.61 m (24 in.),
and a minimum of twelve traverse points shall be used in all other cases.
The traverse points shall be located according to Method 1. The use of
fewer points is subject to the approval of the Administrator. Select a
suitable probe and probe length such that all traverse points can be
sampled. Consider sampling from opposite sides of the stack (four total
sampling ports) for large stacks, to permit use of shorter probe lengths.
Mark the probe with heat resistant tape or by some other method to
-------
1-67
denote the proper distance into the stack or duct for each sampling
point. Place known volumes of water in the first two impingers. Weigh
and record the weight of the silica gel to the nearest 0.5 g, and
transfer the silica gel to the fourth impinger; alternatively, the
silica gel may first be transferred to the impinger, and the weight of
the silica gel plus impinger recorded.
2.2.2 Select a total sampling time such that a minimum total gas
volume of 0.60 scm (21 scf) will be collected, at a rate no greater than
0.021 m /min (0.75 cfm). When both moisture content and pollutant
emission rate are to be determined, the moisture determination shall be
simultaneous with, and for the same total length of time as, the pollutant
emission rate run, unless otherwise specified in an applicable subpart of
the standards.
2.2.3 Set up the sampling train as shown in Figure 4-1. Turn on
the probe heater and (if applicable) the filter heating system to
temperatures of about 120°C (248°F), to prevent water condensation
ahead of the condenser; allow time for the temperatures to stabilize.
Place crushed ice in the ice bath container. It is recommended, but
not required, that a leak check be done, as follows: Disconnect the
probe from the first impinger or (if applicable) from the filter holder.
Plug the inlet to the first impinger (or filter holder) and pull a
380 mm (15 in.) Hg vacuum; a lower vacuum may be used, provided that
it is not exceeded during the test. A leakage rate in excess of
o
4 percent of the average sampling rate or 0.00057 m /min (0.02 cfm),
whichever is less, is unacceptable. Following the leak check,
reconnect the probe to the sampling train.
-------
1-68
2.2.4 During the sampling run, maintain a sampling rate
within 10 percent of constant rate, or as specified by the
Administrator. For each run, record the data required on the
example data sheet shown in Figure 4-2. Be sure to record the
dry gas meter reading at the beginning and end of each sampling
time increment and whenever sampling is halted. Take other
appropriate readings at each sample point, at least once during
each time increment.
2.2.5 To begin sampling, position the probe tip at the first
traverse point. Immediately start the pump and adjust the flow to the
desired rate. Traverse the cross section, sampling at each traverse
point for an equal length of time. Add more ice and, if necessary, salt
to maintain a temperature of less than 20°C (68°F) at the silica gel
outlet.
2.2.6 After collecting the sample, disconnect the probe from the
filter holder (or from the first impinger) and conduct a leak check
(mandatory) as described in Section 2.2.3. Record the leak rate. If
the leakage rate exceeds the allowable rate, the tester shall either
reject the test results or shall correct the sample volume as in
Section 6.3 of Method 5. Next, measure the volume of the moisture
condensed to the nearest ml. Determine the increase in weight of the
silica gel (or silica gel plus impinger) to the nearest 0.5 g. Record
this information (see example data sheet, Figure 4-3) and calculate the
moisture percentage, as described in 2.3 below.
2.3 Calculations. Carry out the following calculations, retaining
at least one extra decimal figure beyond that of the acquired data.
Round off figures after final calculation.
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1-69
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FINAL
INITIAL
DIFFERENCE
IMPINGER
VOLUME,
ml
SILICA GEL
WEIGHT.
9
Figure 43. Analytical data - reference method.
-------
1-71
2.3.1 Nomenclature.
B = Proportion of water vapor, by volume, in the gas stream.
MW = Molecular weight of water, 18.0 g/g-mole (18.0 Ib/lb-mole).
P = Absolute pressure (for this method, same as barometric
pressure) at the dry gas meter, mm Hg (in. Hg).
Pstd = standard absolute pressure, 760 mm Hg (29.92 in. Hg).
R = Ideal gas constant, 0.06236 (mm Hg)(m3)/(g-mole)(°K)
for metric units and 21.85 (in. Hg)(ft3)/(lb-mole)(°R)
for English units.
T = Absolute temperature at meter, °K (°R).
T td = Standard absolute temperature, 293°K (528°R).
V = Dry gas volume measured by dry gas meter, dcm (dcf).
AV = Incremental dry gas volume measured by dry gas meter at
each traverse point, dcm (dcf).
V / ..* = Dry gas volume measured by the dry gas meter, corrected
to standard conditions, dscm (dscf).
V , ..% = Volume of water vapor condensed corrected to standard
conditions, scm (scf).
V / . .\ = Volume of water vapor collected in silica gel corrected
to standard conditions, scm (scf).
Vf = Final volume of condenser water, ml.
V. = Initial volume, if any, of condenser water, ml.
W,. = Final weight of silica gel or silica gel plus impinger, g.
W. = Initial weight of silica gel or silica gel plus impinger, g.
Y = Dry gas meter calibration factor.
PW = Density of water, 0.9982 g/ml (0.002201 Ib/ml).
-------
1-72
2.3.2 Volume of water vapor condensed.
v . (WpwRTstd
V(std) -
f
where:
(V - V) Equation 4-1
= 0.001333 m /ml for metric units
= 0.04707 ft3/ml for English units
2.3.3 Volume of water vapor collected in silica gel.
V
_ ("f Hl> RTstd
wsg(std)
= K2 (Wf - \i.) Equation 4-2
where:
3
K« = 0.001335 m /g for metric units
= 0.04715 ft3/g for English units
2.3.4 Sample gas volume.
(fV
vm(std)= y
s K3Y »!!> Equation 4-3
m
where:
K3 = 0.3858 °K/mm Hg for metric units
» 17.64 °R/in. Hg for English units
Note: If the post-test leak rate (Section 2.2.6) exceeds the
allowable rate, correct the value of Vm in Equation 4-3, as described
in Section 6.3 of Method 5.
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1-73
2.3.5 Moisture Content.
Bws = Vwc(std) + Vws9(std)
ws Vwc(std) wsg(std) m(std)
Note: In saturated or moisture droplet-laden gas streams, two
calculations of the moisture content of the stack gas shall be made, one
using a value based upon the saturated conditions (see Section 1.2),
and another based upon the results of the impinger analysis. The
lower of these two values of B shall be considered correct.
ws
2.3.6 Verification of constant sampling rate. For each time
increment, determine the AV . Calculate the average. If the
m
value for any time increment differs from the average by more than
10 percent, reject the results and repeat the run.
3. Approximation Method
The approximation method described below is presented only as
a suggested method (see Section 1.2).
3.1 Apparatus.
3.1.1 Probe. Stainless steel or glass tubing, sufficiently
heated to prevent water condensation and equipped with a filter
(either in-stack or heated out-stack) to remove particulate matter.
A plug of glass wool, inserted into the end of the probe, is a
satisfactory filter.
3.1.2 Impingers. Two midget impingers, each with 30 ml
capacity, or equivalent.
3.1.3 Ice Bath. Container and ice, to aid in condensing
moisture in impingers.
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1-74
3.1.4 Drying Tube. Tube packed with new or regenerated 6- to 16-
mesh indicating-type silica gel (or equivalent desiccant), to dry the
sample gas and to protect the meter and pump.
3.1.5 Valve. Needle valve, to regulate the sample gas flow rate.
3.1.6 Pump. Leak-free, diaphragm type, or equivalent, to pull the
gas sample through the train.
3.1.7 Volume meter. Dry gas meter, sufficiently accurate to
measure the sample volume within 2%, and calibrated over the range of
flow rates and conditions actually encountered during sampling.
3.1.8 Rate Meter. Rotameter, to measure the flow range from
0. to 3 1pm (O.to 0.11 cfm).
3.1.9 Graduated Cylinder. 25 ml.
3.1.10 Barometer, Mercury, aneroid, or other barometer, as
described in Section 2.1.5 above.
3.1.11 Vacuum Gauge. At least 760 mm Hg (30 in. Hg) gauge, to be
usad for the sampling leak check.
3.2 Procedure.
3.2.1 Place exactly 5 ml distilled water in each impinger.
Leak check the sampling train as follows: Temporarily insert a vacuum
gauge at or near the probe inlet; then, plug the probe inlet and pull
a vacuum of at least 250 mm Hg (10 in. Hg). Note the time rate of
change of the dry gas meter dial; alternatively, a rotameter (0-40
cc/min) may be temporarily attached to the dry gas meter outlet to
determine the leakage rate. A leak rate not in excess of 2 percent
of the average sampling rate is acceptable. Note: Carefully release
the probe inlet plug before turning off the pump.
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HEATED PROBE
SILICA GEL TUBE
RATE METER (
VALVE
FILTER
(GLASS WOOL)
DRY GAS
V METER
MIDGET IMPINGERS
PUMP
Figure 4-4. Moisture-sampling train - approximation method.
LOCATION.
TEST
COMMENTS
DATE
OPERATOR
BAROMETRIC PRESSURE
CLOCK TIME
GAS VOLUME THROUGH
METER, (Vm),
m3 (ft3)
RATE METER SETTING
m3/min. (ft3/min.)
METER TEMPERATURE.
°C (°F)
Figure 4-5. Field moisture determination - approximation method.
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3.2.2 Connect the probe, insert it into the stack, and sample
at a constant rate of 2 1pm (0.071 cfm). Continue sampling until
o
the dry gas meter registers about 30 liters (1.1 ft ) or until
visible liquid droplets are carried over from the first impinger
to the second. Record temperature, pressure, and dry gas meter
readings as required by Figure 4-5.
3.2.3 After collecting the sample, combine the contents of
the two impingers and measure the volume to the nearest 0.5 ml.
3.3 Calculations. The calculation method presented is
designed to estimate the moisture in the stack gas; therefore,
other data, which are only necessary for accurate moisture determina-
tions, are not collected. The following equations adequately
estimate the moisture content, for the purpose of determining
isokinetic sampling rate settings.
3.3.1 Nomenclature.
B = Approximate proportion, by volume, of water vapor in
wm
the gas stream leaving the second impinger, 0.025.
B = Water vapor in the gas stream, proportion by volume.
ws
M = Molecular weight of water, 18.0 g/g-mole (18.0 l!b/lb-mole)
P = Absolute pressure (for this method, same as barometric
pressure) at the dry gas meter.
Pstd = standard absolute pressure, 760 mm Hg (29.92 in. Hg).
R = Ideal gas constant, 0.06236 (m Hq)(m3)/(g-mole)(°K) for
metric units and 21.85 (in. Hg)(ft3)/lb-mole)(°R) for
English units.
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T = Absolute temperature at meter, °K (°R).
m
T .. = Standard absolute temperature, 293°K (528°R).
Vf = Final volume of impinger contents, ml.
V. = Initial volume of impinger contents, ml.
V = Dry gas volume measured by dry gas meter, dcm (dcf).
V / .,>= Dry gas volume measured by dry gas meter, corrected
to standard conditions, dscm (dscf).
V / . .\=Volume of water vapor condensed, corrected to
standard conditions, scm (scf).
Y = Dry gas meter calibration factor.
p , = Density of water, 0.9982 g/ml (0.002201 Ib/ml).
w
3.3.2 Volume of water vapor collected.
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1-78
where:
o
K2 = 0.3858 K/mm Hg for metric units.
= 17.64 °R/in. Hg for English units.
3.3.4 Approximate moisture content.
Vwc(std)
Equation 4-7
4. Calibration
4.1 For the reference method, calibrate equipment as specified in
the following sections of Method 5: Section 5.3 (metering system);
Section 5.5 (temperature gauges); and Section 5.7 (barometer). The
recommended leak check of the metering system (Section 5.6 of Method 5)
also applies to the reference method. For the approximation method, use
the procedures outlined in Section 5.1.1 of Method 6 to calibrate the
metering system, and the procedure of Method 5, Section 5.7 to calibrate
the barometer.
5. Bibliography
1. Air Pollution Engineering Manual (Second Edition). Danielson,
J. A. (ed.). U. S. Environmental Protection Agency, Office of Air
Quality Planning and Standards. Research Triangle Park, N. C. Publication
No. AP-40. 1973.
2. Devorkin, Howard, et al. Air Pollution Source Testing Manual.
Air Pollution Control District, Los Angeles, Calif. November, 1963.
3. Methods for Determination of Velocity, Volume, Dust and Mist
Content of Gases. Western Precipitation Division of Joy Manufacturing
Co. Los Angeles, Calif. Bulletin WP-50. 1968.
-------
DETERMINATION OF PARTICULATE EMISSIONS
FROM STATIONARY SOURCES
METHODS
-------
1-79
METHOD 5DETERMINATION OF PARTICULATE
EMISSIONS FROM STATIONARY SOURCES
1. Principle and Applicability
1.1 Principle. Particulate matter is withdrawn isokinetically
from the source and collected on a glass fiber filter maintained at
a temperature in the range of 120 +_ 14°C (248 +_25°F) or such other
temperature as specified by an applicable subpart of the standards
or approved by the Administrator, U. S. Environmental Protection
Agency, for a particular application. The particulate mass, which
includes any material that condenses at or above the filtration
temperature, is determined gravimetrically after removal of uncombined
water.
1.2 Applicability. This method is applicable for the determina-
tion of particulate emissions from stationary sources.
2. Apparatus
2.1 Sampling Train. A schematic of the sampling train used in
this method is shown in Figure 5-1. Complete construction details
are given in APTD-0581 (Citation 2 in Section 7); commercial models
of this train are also available. For changes from APTD-0581 and
for allowable modifications of the train shown in Figure 5-1, see
the following subsections.
The operating and maintenance procedures for the sampling train
are described in APTD-0576 (Citation 3 in Section 7). Since correct
usage is important in obtaining valid results, all users should read
APTD-0576 and adopt the operating and maintenance procedures outlined
in it, unless otherwise specified herein. The sampling train consists
of the following components:
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2.1.1 Probe Nozzle. Stainless steel (316) or glass with sharp,
tapered leading edge. The angle of taper shall be <30° and the
taper shall be on the outside to preserve a constant internal diameter.
The probe nozzle shall be of the button-hook or elbow design, unless
otherwise specified by the Administrator. If made of stainless steel,
the nozzle shall be constructed from seamless tubing; other materials
of construction may be used, subject to the approval of the
Administrator.
A range of nozzle sizes suitable for isokinetic sampling should
be available, e.g., 0.32 to 1.27 cm (1/8 to 1/2 in.)or larger if
higher volume sampling trains are usedinside diameter (ID) nozzles
in increments of 0.16 cm (1/16 in.). Each nozzle shall be calibrated
according to the procedures outlined in Section 5.
2.1.2 Probe Liner. Borosilicate or quartz glass tubing with a
heating system capable of maintaining a gas temperature at the exit
end during sampling of 120 +_ 14°C (248 +_ 25°F), or such other tempera-
ture as specified by an applicable subpart of the standards or
approved by the Administrator for a particular application. (The
tester may opt to operate the equipment at a temperature lower than
that specified.) Since the actual temperature at the outlet of the
probe is not usually monitored during sampling, probes constructed
according to APTD-0581 and utilizing the calibration curves of
APTD-0576 (or calibrated according to the procedure outlined in
APTD-0576) will be considered acceptable.
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c
"o.
E
(D
l/l
O
TO
ro
Q_
in
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-------
1-82
Either borosilicate or quartz glass probe liners may be used
for stack temperatures up to about 480°C (900°F); quartz liners
shall be used for temperatures between 480 and 900°C (900 and 1650°F).
Both types of liners may be used at higher temperatures than specified
for short periods of time, subject to the approval of the Administrator.
The softening temperature for borosilicate is 820°C (1508°F), and tor
quartz it is 1500°C (2732°F).
Whenever practical, every effort should be made to use borosilicate
or quartz glass probe liners. Alternatively, metal liners (e.g., 316
stainless steel, Incoloy 825, or other corrosion resistant metals)
made of seamless tubing may be used, subject to the approval of the
Administrator.
2.1.3 Pi tot Tube. Type S, as described in Section 2.1 of
Method 2, or other device approved by the Administrator. The pi tot
tube shall be attached to the probe (as shown in Figure 5-1) to allow
constant monitoring of the stack gas velocity. The impact (high
pressure) opening plane of the pitot tube shall be even with or
above the nozzle entry plane (see Method 2, Figure 2-6b) during
sampling. The Type S pitot tube assembly shall have a known coefficient,
determined as outlined in Section 4 of Method 2.
2.1.4 Differential Pressure Gauge. Inclined manometer or
equivalent device (two), as described in Section 2.2 of Method 2.
One manometer shall be used for velocity head (AP) readings, and
the other, for orifice differential pressure readings.
Mention of trade names or specific products does not constitute
endorsement by the Environmental Protection Agency.
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2.1.5 Filter Holder. Borosllicate glass, with a glass frit
filter support and a silicone rubber gasket. Other materials of
construction (e.g., stainless steel, Teflon, Viton) may be used,
subject to the approval of the Administrator. The holder design shall
provide a positive seal against leakage from the outside or around the
filter. The holder shall be attached immediately at the outlet of
the probe (or cyclone, if used).
2.1.6 Filter Heating System. Any heating system capable of
maintaining a temperature around the filter holder during sampling
of 120 +_ 14°C (248 + 25°F), or such other temperature as specified by
an applicable subpart of the standards or approved by the
Administrator for a particular application. Alternatively, the tester
/
may opt to operate the equipment at a temperature lower than that
specified. A temperature gauge capable of measuring temperature to
within 3°C (5.4°F) shall be installed so that the temperature around
the filter holder can be regulated and monitored during sampling.
Heating systems other than the one shown in APTD-0581 may be used.
2.1.7 Condenser. The following system shall be used to determine
the stack gas moisture content: Four impingers connected in series
with leak-free ground glass fittings or any similar leak-free non-
contaminating fittings. The first, third, and fourth impingers shall
be of the Greenburg-Smith design, modified by replacing the tip with
a 1.3 cm (1/2 in.) ID glass tube extending to about 1.3 cm (1/2 in.)
from the bottom of the flask. The second impinger shall be of the
Greenburg-Smith design with the standard tip. Modifications (e.g.,
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using flexible connections between the impingers, using materials
other than glass, or using flexible vacuum lines to connect the
filter holder to the condenser) may be used, subject to the
approval of the Administrator. The first and second impingers shall
contain known quantities of water (Section 4.1.3), the third shall
be empty, and the fourth shall contain a known weight of silica gel,
or equivalent desiccant. A thermometer, capable of measuring tempera-
ture to within 1°C (2°F) shall be placed at the outlet of the fourth
impinger for monitoring purposes.
Alternatively, any system that cools the sample gas stream and
allows measurement of the water condensed and moisture 'leaving the
condenser, each to within 1 ml or 1 g may be used, subject to the
approval of the Administrator. Acceptable means are to measure the
condensed water either gravimetrically or volumetrically and to measure
the moisture leaving the condenser by: (1) monitoring the temperature
and pressure at the exit of the condenser and using Dal ton's law of
partial pressures; or (2) passing the sample gas stream through a
tared silica gel (or equivalent desiccant) trap with exit gases kept
below 20°C (68°F) and determining the weight gain.
If means other than silica gel are used to determine the amount of
moisture leaving the condenser, it is recommended that silica gel (or
equivalent) still be used between the condenser system and pump to
prevent moisture condensation in the pump and metering devices and
to avoid the need to make corrections for moisture in the metered
volume.
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Note: If a determination of the participate matter collected
in the impingers is desired in addition to moisture content, the
impinger system described above shall be used, without.modification.
Individual States or control agencies requiring this information
shall be contacted as to the sample recovery and analysis of the
impinger contents.
2.1.8 Metering System. Vacuum gauge, leak-free pump, thermometers
capable of measuring temperature to within 3°C (5.4°F), dry gas meter
capable of measuring volume to within 2 percent, and related equipment,
as shown in Figure 5-1. Other metering systems capable of maintaining
sampling rates within 10 percent of isokinetic and of determining
sample volumes to within 2 percent may be used, subject to the approval
of the Administrator. When the metering system is used in conjunction
with a pitot tube, the system shall enable checks of isokinetic rates.
Sampling trains utilizing metering systems designed for higher
flow rates than that described in APTD-0581 or APTD-0576 may be used
provided that the specifications of this method are met.
2.1.9 Barometer. Mercury, aneroid, or other barometer capable
of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg).
In many cases, the barometric reading may be obtained from a nearby
national weather service station, in which case the station value
(which is the absolute barometric pressure) shall be requested and
an adjustment for elevation differences between the weather station
and sampling point shall be applied at a rate of minus 2.5 mm Hg
(0.1 in. Hg) per 30 m (100 ft) elevation increase or vice versa
for elevation decrease.
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1-86
2.1.10 Gas Density Determination Equipment. Temperature
sensor and pressure gauge, as described in Sections 2.3 and 2.4 of
Method 2, and gas analyzer, if necessary, as described in Method 3.
The temperature sensor shall, preferably, be permanently attached
to the pi tot tube or sampling probe in a fixed configuration, such
that the tip of the sensor extends beyond the leading edge of the
probe sheath and does not touch any metal. Alternatively, the sensor
may be attched just prior to use in the field. Note, however, that
if the temperature sensor is attached in the field, the sensor must
be placed in an interference-free arrangement with respect to the
Type S pi tot tube openings (see Method 2, Figure 2-7). As a second
alternative, if a difference of not more than 1 percent in the average
velocity measurement is to be introduced, the temperature gauge need
not be attached to the probe or pitot tube. (This alternative is
subject to the approval of the Administrator.)
2.2 Sample Recovery. The following items are needed:
2.2.1 Probe-Liner and Probe-Nozzle Brushes. Nylon bristle
brushes with stainless steel wire handles. The probe brush shall
have extensions (at least as long as the probe) of stainless steel,
Nylon, Teflon, or similarly inert material. The brushes shall be
properly sized and shaped to brush out the probe liner and nozzle.
2.2.2 Wash BottlesTwo. Glass wash bottles are recommended;
polyethylene wash bottles may be used at the option of the tester.
It is recommended that acetone not be stored in polyethylene bottles
for longer than a month.
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2.2.3 Glass Sample Storage Containers. Chemically resistant,
borosilicate glass bottles, for acetone washes, 500 ml or 1000 ml.
Screw cap liners shall either be rubber-backed Teflon or shall be
constructed so as to be leak-free and resistant to chemical attack
by acetone. (Narrow mouth glass bottles have been found to be less
prone to leakage.) Alternatively, polyethylene bottles may be used.
2.2.4 Petri Dishes. For filter samples, glass or polyethylene,
unless otherwise specified by the Administrator.
2.2.5 Graduated Cylinder and/or Balance. To measure condensed
water to within 1 ml or 1 g. Graduated cylinders shall have sub-
divisions no greater than 2 ml. Most laboratory balances are capable
of weighing to the nearest 0.5 g or less. Any of these balances is
suitable for use here and in Section 2.3.4.
2.2.6 Plastic Storage Containers. Air-tight containers to
store silica gel.
2.2.7 Funnel and Rubber Policeman. To aid in transfer of silica
gel to container; not necessary if silica gel 1s weighed 1n the field.
2.2.8 Funnel. Glass or polyethylene, to aid in sample recovery.
2.3 Analysis. For analysis, the following equipment is needed:
2.3.1 Glass Weighing Dishes.
2.3.2 Desiccator.
2.3.3 Analytical Balance. To measure to within 0.1 mg.
2.3.4 Balance. To measure to within 0.5 g.
2.3.5 Beakers. 250 ml.
2.3.6 Hygrometer. To measure the relative humidity of the
laboratory environment.
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2.3.7 Temperature Gauge. To measure the temperature of the
laboratory environment.
3. Reagents
3.1 Sampling. The reagents used in sampling are as follows:
3.1.1 Filters. Glass fiber filters, without organic binder,
exhibiting at least 99.95 percent efficiency (<0.05 percent penetration)
on 0.3-micron dioctyl phthalate smoke particles. The filter efficiency
test shall be conducted in accordance with ASTM standard method
D 2986-71. Test data from the supplier's quality control program are
sufficient for this purpose. .
3.1.2 Silica Gel. Indicating.type, 6 to 16 mesh. If previously
used, dry at 175°C (350°F) for 2 hours. New silica gel may be used
as received. Alternatively, other types of desiccants (equivalent or
better) may be used, subject to the approval of the Administrator.
3.1.3 Water. When analysis of the material caught in the
impingers is required, distilled water shall be used. Run blanks
prior to field use to eliminate a high blank on test samples.
3.1.4 Crushed Ice.
3.1.5 Stopcock Grease. Acetone-insoluble, heat-stable silicone
grease. This is not necessary if screw-on connectors with Teflon
sleeves, or similar, are used. Alternatively, other types of stopcock
grease may be used, subject to the approval of the Administrator.
3.2 Sample Recovery. Acetonereagent grade, ^0.001 percent
residue, in glass bottlesis required. Acetone from metal containers
generally has a high residue blank and should not be used. Sometimes,
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1-89
suppliers transfer acetone to glass bottles from metal containers;
this, acetone blanks shall be run prior to field use and only
acetone with low blank values (<0.001 percent) shall be used. In
no case shall a blank value of greater than 0.001 percent of the
weight of acetone used be subtracted from the sample weight.
3.3 Analysis. Two reagents are required for the analysis:
3.3.1 Acetone. Same as 3.2.
3.3.2 Desiccant. Anhydrous calcium suTfate, indicating type.
Alternatively, other types of desiccants may be used, subject to the
approval of the Administrator.
4. Procedure
4.1 Sampling. The complexity of this method is such that, in
order to obtain reliable results, testers should be trained and
experienced with the test procedures.
4.1.1 Pretest Preparation. All the components shall be maintained
and calibrated according to the procedure described in APTD-0576, unless
otherwise specified herein.
Weigh several 200 to 300 g portions of silica gel in air-tight
containers to the nearest 0.5 g. Record the total weight of the
silica gel plus container, on each container. As an alternative, the
silica gel need not be preweighed, but may be weighed directly in its
impinger or sampling holder just prior to train assembly.
Check filters visually against light for irregularities and
flaws or pinhole leaks. Label filters of the proper diameter on the
back side near the edge using numbering machine ink. As an alternative,
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label the shipping containers (glass or plastic petri dishes) and
keep the filters in these containers at all times except during
sampling and weighing.
Desiccate the filters at 20 +_ 5.6°C (68 +_ 10°F) and ambient
pressure for at least 24 hours and weigh at intervals of at least
6 hours to a constant weight, i.e., <0.5 mg change from previous
weighing; record results to the nearest 0.1 mg. During each
weighing the filter must not be exposed to the laboratory atmosphere
for a period greater than 2 minutes and a relative humidity above
50 percent. Alternatively (unless otherwise specified by the
Administrator), the filters may be oven dried at 105°C (220°F) for
2 to 3 hours, desiccated for 2 hours, and weighed. Procedures other
than those described, which account for relative humidity effects,
may be used, subject to the approval of the Administrator.
4.1.2 Preliminary Determinations. Select the sampling site and
the minimum number of sampling points according to Method 1 or as
specified by the Administrator. Determine the stack pressure,
temperature, and the range of velocity heads using Method 2; it is
recommended that a leak-check of the pi tot lines (see Method 2,
Section 3.1) be performed. Determine the moisture content using
Approximation Method 4 or its alternatives for the purpose of making
isokinetic sampling rate settings. Determine the stack gas dry
molecular weight, as described in Method 2, Section 3.6; if integrated
Method 3 sampling is used for molecular weight determination, the
Integrated bag sample shall be taken simultaneously with, and for
the same total length of time as, the particulate sample run.
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Select a nozzle size based on the range of velocity heads, such
that it is not necessary to change the nozzle size in order to maintain
isokinetic sampling rates. During the run, do not change the nozzle
size. Ensure that the proper differential pressure gauge is chosen for
the range of velocity heads encountered (see Section 2.2 of Method 2).
Select a suitable probe liner and probe length such that all
traverse points can be sampled. For large stacks, consider sampling
from opposite sides of the stack to reduce the length of probes.
Select a total sampling time greater than or equal to the minimum
total sampling time specified in the test procedures for the specific
industry such that (1) the sampling time per point is not less than 2
min.(or some greater time interval as specified by the Administrator),
and (2) the sample volume taken (corrected to standard conditions) will
exceed the required minimum total gas sample volume. The latter is
based on an approximate average sampling rate.
The sampling time at each point shall be the same. It is recom-
mended that the number of minutes sampled at each point be an integer or
an integer plus onehalf minute, in order to avoid timekeeping errors.
In some circumstances, e.g., batch cycles, it may be necessary to
sample for shorter times at the traverse points and to obtain smaller
gas sample volumes. In these cases, the Administrator's approval must
first be obtained.
4.1.3 Preparation of Collection Train. During preparation and
assembly of the sampling train, keep all openings where contamination
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can occur covered until just prior to assembly or until sampling
is about to begin.
Place 100 ml of water in each of the first two irnpingers, leave
the third impinger empty, and transfer approximately 200 to 300 g of
preweighed silica gel from its container to the fourth impinger.
More silica gel may be used, but care should be taken to ensure that
it is not entrained and carried out from the impinger during sampling.
Place the container in a clean place for later use in the sample
recovery. Alternatively, the weight of the silica gel plus impinger
may be determined to the nearest 0.5 g and recorded.
Using a tweezer or clean disposable surgical gloves, place a
labeled (identified) and weighed filter in the filter holder. Be sure
that the filter is properly centered and the gasket properly placed
so as to prevent the sample gas stream from circumventing the filter.
Check the filter for tears after assembly is completed.
When glass liners are used, install the selected nozzle using
a Viton A 0-ring when stack temperatures are less than 260°C (500°F)
and an asbestos string gasket when temperatures are higher. See
APTD-0576 for details. Other connecting systems using either 316
stainless steel or Teflon ferrules may be used. When metal liners
are used, install the nozzle as above or by a leak-free direct
mechanical connection. Mark the probe with heat resistant tape or
by some other method to denote the proper distance Into the stack or
duct for each sampling point.
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Set up the train as in Figure 5-1, using (if necessary) a very
light coat of silicone grease on all ground glass joints, greasing
only the outer portion (see APTD-0576) to avoid possibility of
contamination by the silicone grease. Subject to the approval of
the Administrator, a glass cyclone may be used between the probe and
filter holder when the total particulate catch is expected to exceed
100 mg or when water droplets are present in the stack gas.
Place crushed ice around the impingers.
4.1.4 Leak-Check Procedures.
4.1.4.1 Pretest Leak-Check. A pretest leak-check is recommended,
but not required. If the tester opts to conduct the pretest leak-check,
the following procedure shall be used.
After the sampling train has been assembled, turn on and set the
filter and probe heating systems at the desired operating temperatures.
Allow time for the temperatures to stabilize. If a Viton A 0-ring or
other leak-free connection is used in assembling the probe nozzle to
the probe liner, leak-check the train at the sampling site by plugging
the nozzle and pulling a 380 mm Hg (15 in. Hg) vacuum.
Note: A lower vacuum may be used, provided that it is not exceeded
during the test.
If an asbestos string is used, do not connect the probe to the
train during the leak-check. Instead, leak-check the train by first
plugging the inlet to the filter holder (cyclone, if applicable) and
pulling a 380 mm Hg (15 in. Hg) vacuum (see Note Immediately above).
Then connect the probe to the train and leak-check at about 25 mm Hg
(1 in. Hg) vacuum; alternatively, the probe may be leak-checked with
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the rest of the sampling train, in one step, at 380 mm Hg (15 in. Hg)
vacuum. Leakage rates in excess of 4 percent of the average sampling
^
rate or 0.00057 m /min (0.02 cfm), whichever is less, are unacceptable.
The following leak-check instructions for the sampling train
described in APTD-0576 and APTD-0581 may be helpful. Start the pump
with bypass valve fully open and coarse adjust valve completely closed.
Partially open the coarse adjust valve and slowly close the bypass
valve until the desired vacuum is reached. Do not reverse direction
of bypass valve; this will cause water to back up into the filter
holder. If the desired vacuum is exceeded, either leak-check at
this higher vacuum or end the leak check as shown below and start over.
When the leak-check is completed, first slowly remove the plug
from the inlet to the probe, filter holder, or cyclone (if applicable)
and immediately turn off the vacuum pump. This prevents the water in
the impingers from being forced backward into the filter holder and
silica gel from being entrained backward into the third impinger.
4.1.4.2 Leak-Checks During Sample Run. If, during the sampling
run, a component (e.g., filter assembly or impinger) change becomes
necessary, a leak-check shall be conducted immediately before the
change is made. The leak-check shall be done according to the procedure
outlined in Section 4.1.4.1 above, except that it shall be done at a
vacuum equal to or greater than the maximum value recorded up to that
point in the test. If the leakage rate is found to be no greater than
o
0.00057 m /min (0.02 cfm) or 4 percent of the average sampling rate
-------
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(whichever is less), the results are acceptable, and no correction
will need to be applied to the total volume of dry gas metered;
if, however, a higher leakage rate is obtained, the tester shall
either record the leakage rate and plan to correct the sample volume
as shown in Section 6.3 of this method, or shall void the sampling run.
Immediately after component changes, leak-checks are optional;
if such leak-checks are done, the procedure outlined in Section 4.1.4.1
above shall be used.
4.1.4.3 Post-test Leak-Check. A leak-check is mandatory at the
conclusion of each sampling run. The leak-check shall be done in
accordance with the procedures outlined in Section 4.1.4.1, except
that it shall be conducted at a vacuum equal to or greater than the
maximum value reached during the sampling run. If the leakage rate
is found to be no greater than 0.00057 m /min (0.02 cfm) or 4 percent
of the average sampling rate (whichever is less), the results are
acceptable, and no correction need be applied to the total volume of
dry gas metered. If, however, a higher leakage rate is obtained, the
tester shall either record the leakage rate and correct the sample
volume as shown in Section 6.3 of this method, or shall void the
sampling run.
4.1.5 Particulate Train Operation. During the sampling run,
maintain an isokinetic sampling rate (within 10 percent of true
isokinetic unless otherwise specified by the Administrator) and a
temperature around the filter of 120 +_ 14°C (248 + 25°F), or such other
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1-96
temperature as specified by an applicable subpart of the standards
or approved by the Administrator.
For each run, record the data required on a data sheet such as
the one shown in Figure 5-2. Be sure to record the initial dry gas
meter reading. Record the dry gas meter readings at the beginning
and end of each sampling time increment, when changes in flow rates
are made, before and after each leak check, and when sampling is halted.
Take other readings required by Figure 5-2 at least once at each sample
point during each time increment and additional readings when significant
changes (20 percent variation in velocity head readings) necessitate
additional adjustments in flow rate. Level and zero the manometer.
Because the manometer level and zero may drift due to vibrations and
temperature changes, make periodic checks during the traverse.
Clean the portholes prior to the test run to minimize the chance
of sampling deposited material. To begin sampling, remove the nozzle
cap, verify that the filter and probe heating systems are up to
temperature, and that the pitot tube and probe are properly positioned.
Position the nozzle at the first traverse point with the tip pointing
directly into the gas stream. Immediately start the pump and adjust
the flow to isokinetic conditions. Nomographs are available, which
aid in the rapid adjustment of the isokinetic sampling rate without
excessive computations. These nomographs are designed for use when the
Type S pitot tube coefficient is 0.85 +^0.02, and the stack gas
equivalent density (dry molecular weight) is equal to 29 +_4. APTD-0576
details the procedure for using the nomographs. If C and M. are
outside the above stated ranges, do not use the nomographs unless
appropriate steps (see Citation 7 in Section 7) are taken to compensate
for the deviations.
-------
1-97
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1-98
When the stack is under significant negative pressure (height
of impinger stem), take care to close the coarse adjust valve before
inserting the probe into the stack to prevent water from backing into
the filter holder. If necessary, the pump may be turned on with the
coarse adjust valve closed.
When the probe is in position, block off the openings around
the probe and porthole to prevent unrepresentative dilution of the
gas stream.
Traverse the stack cross-section, as required by Method 1 or as
specified by the Administrator, being careful not to bump the probe
nozzle into the stack walls when sampling near the walls or when
removing or inserting the probe through the portholes; this minimizes
the chance of extracting deposited material.
During the test run, make periodic adjustments to keep the
temperature around the filter holder at the proper level; add more
ice and, if necessary, salt to maintain a temperature of less than
20°C (68°F) at the condenser/silica gel outlet. Also, periodically
check the level and zero of the manometer.
If the pressure drop across the filter becomes too high, making
isokinetic sampling difficult to maintain, the filter may be replaced
in the midst of a sample run. It is recommended that another complete
filter assembly be used rather than attempting to change the filter
itself. Before a new filter assembly is installed, conduct a leak-check
(see Section 4.1.4.2). The total particulate weight shall include the
summation of all filter assembly catches.
-------
1-99
A single train shall be used for the entire sample run, except
in cases where simultaneous sampling is required in two or more
separate ducts or at two or more different locations within the same
duct, or, in cases where equipment failure necessitates a change of
trains. In all other situations, the use of two or more trains will
be subject to the approval of the Administrator.
Note that when two or more trains are used, separate analyses of
the front-half and (if applicable) impinger catches from each train
shall be performed, unless identical nozzle sizes were used on all
trains, in which case, the front-half catches from the individual trains
may be combined (as may the impinger catches) and one analysis of front-
half catch and one analysis of impinger catch may be performed. Consult
with the Administrator for details concerning the calculation of
results when two or more trains are used.
At the end of the sample run, turn off the coarse adjust valve,
remove the probe and nozzle from the stack, turn off the pump, record
the final dry gas meter reading, and conduct a post-test leak-check, as
outlined in Section 4.1.4.3. Also, leak-check the pitot lines as
described in Method 2, Section 3.1; the lines must pass this leak-check,
in order to validate the velocity head data.
4.1.6 Calculation of Percent Isokinetic. Calculate percent
isokinetic (see Calculations, Section 6) to determine whether the run
was valid or another test run should be made. If there was difficulty
in maintaining isokinetic rates due to source conditions, consult with
the Administrator for possible variance on the isokinetic rates.
-------
I-100
4.2 Sample Recovery. Proper cleanup procedure begins as soon
as the probe is removed from the stack at the end of the sampling
period. Allow the probe to cool.
When the probe can be safely handled, wipe off all external
particulate matter near the tip of the probe nozzle and place a cap
over it to prevent losing or gaining particulate matter. Do not cap
off the probe tip tightly while the sampling train is cooling down
as this would create a vacuum in the filter holder, thus drawing water
from the impingers into the filter holder.
Before moving the sample train to the cleanup site, remove the
probe from the sample train, wipe off the silicone grease, and cap
the open outlet of the probe. Be careful not to lose any condensate
that might be present. Wipe off the silicone grease from the filter
inlet where the probe was fastened and cap it. Remove the umbilical
cord from the last impinger and cap the impinger. If a flexible line
is used between the first impinger or condenser and the filter holder,
disconnect the line at the filter holder and let any condensed water
or liquid drain into the impingers or condenser. After wiping off the
silicone grease, cap off the filter holder outlet and impinger inlet.
Either ground-glass stoppers, plastic caps, or serum caps may be used
to close these openings.
Transfer the probe and filter-impinger assembly to the cleanup
area. This area should be clean and protected from the wind so that
the chances of contaminating or losing the sample will be minimized.
-------
1-101
Save a portion of the acetone used for cleanup as a blank. Take
200 ml of this acetone directly from the wash bottle being used and
place it in a glass sample container labeled "acetone blank."
Inspect the train prior to and during disassembly and note any
abnormal conditions. Treat the samples as follows:
Container No. 1. Carefully remove the filter from the filter holder
and place it in its identified petri dish container. Use a pair of
tweezers and/or clean disposable surgical gloves to handle the filter.
If it is necessary to fold the filter, do so such that the particulate
cake is inside the fold. Carefully transfer to the petri dish any
particulate matter and/or filter fibers which adhere to the filter
holder gasket, by using a dry Nylon bristle brush and/or a sharp-edged
blade. Seal the container.
Container No. 2. Taking care to see that dust on the outside
of the probe or other exterior surfaces does not get into the sample,
quantitatively recover particulate matter or any condensate from the
probe nozzle, probe fitting, probe liner, and front half of the
filter holder by washing these components with acetone and placing
the wash in a glass container. Distilled water may be used instead
of acetone when approved by the Administrator and shall be used when
specified by the Administrator; in these cases, save a water blank
and follow the Administrator's directions on analysis. Perform the
acetone rinses as follows:
-------
1-102
Carefully remove the probe nozzle and clean the inside surface
by rinsing with acetone from a wash bottle and brushing with a Nylon
bristle brush. Brush until the acetone rinse shows no visible particles,
after which make a final rinse of the inside surface with acetone. ,
Brush and rinse the inside parts of the Swagelok fitting with
acetone in a similar way until no visible particles remain.
Rinse the probe liner with acetone by tilting and rotating the
probe while squirting acetone into its upper end so that all inside
surfaces will be wetted with acetone. Let the acetone drain from the
lower end into the sample container. A funnel (glass or polyethylene)
may be used to aid in transferring liquid washes to the container. Follow
the acetone rinse with a probe brush. Hold the probe in an inclined
position, squirt acetone into the upper end as the probe brush is being
pushed with a twisting action through the probe; hold a sample container
underneath the lower end of the probe, and catch any acetone and particu-
late matter which is brushed from the probe. Run the brush through the
probe three times or more until no visible particulate matter is carried
out with the acetone or until none remains in the probe liner on visual
inspection. With stainless steel or other metal probes, run the brush
through in the above prescribed manner at least six times since metal
probes have small crevices in which particulate matter can be entrapped.
Rinse the brush with acetone, and quantitatively collect these washings
in the sample container. After the brushing, make a final acetone rinse
of the probe as described above.
-------
1-103
It is recommended that two people be used to clean the probe
to minimize sample losses. Between sampling runs, keep brushes clean
and protected from contamination.
After ensuring that all joints have been wiped clean of silicone
grease, clean the inside of the front half of the filter holder by
rubbing the surfaces with a Nylon bristle brush and rinsing with
acetone. Rinse each surface three times or more if needed to remove
visible particulate. Make a final rinse of the brush and filter
holder. Carefully rinse out the glass cyclone, also (if applicable).
After all acetone washings and particulate matter have been collected
in the sample container, tighten the lid on the sample container so
that acetone will not leak out when it is shipped to the laboratory.
Mark the height of the fluid level to determine whether or not
leakage occurred during transport. Label the container to clearly
identify its contents.
Container No. 3. Note the color of the indicating silica gel
to determine if it has been completely spent and make a notation of
its condition. Transfer the silica gel from the fourth impinger to
its original container and seal. A funnel may make it easier to pour
the silica gel without spilling. A rubber policeman may be used as
an aid in removing the silica gel from the impinger. It is not
necessary to remove the small amount of dust particles that may adhere
to the impinger wall and are difficult to remove. Since the gain in
weight is to be used for moisture calculations, do not use any water
-------
1-104
or other liquids to transfer the silica gel. If a balance is
available in the field, follow the procedure for container No. 3
in Section 4.3.
Impinger Water. Treat the impingers as follows: Make a
notation of any color or film in the liquid catch. Measure the
liquid which is in the first three impingers to within +1 ml by
using a graduated cylinder or by weighing it to within +0.5 g by
using a balance (if one is available). Record the volume or weight
of liquid present. This information is required to calculate the
moisture content of the effluent gas.
Discard the liquid after measuring and recording the volume or
weight, unless analysis of the impinger catch is required (see Note,
Section 2.1.7).
If a different type of condenser is used, measure the amount of
moisture condensed either volumetrically or gravimetrically.
Whenever possible, containers should be shipped in such a way that
they remain upright at all times.
4.3 Analysis. Record the data required on a sheet such as the
one shown in Figure 5-3. Handle each sample container as follows:
Container No. 1. Leave the contents in the shipping container
or transfer the filter and any loose particulate from the sample
container to a tared glass weighing dish. Desiccate for 24 hours
in a desiccator containing anhydrous calcium sulfate. Weigh to a
constant weight and report the results to the nearest 0.1 mg. For
purposes of this Section, 4.3, the term "constant weight" means
-------
1-105
Plant
Date
Run No
Filter No
Amount liquid lost during transport
Acetone blank volume, ml
Acetone wash volume, ml
Acetone blank concentration, mg/mg (equation 5-4).
Acetone wash blank, mg (equation 5-5)
CONTAINER
NUMBER
1
2
TOTAL
WEIGHT OF PARTICULATE COLLECTED,
mg
FINAL WEIGHT
^X^
TARE WEIGHT
^XI^
Less acetone blank
Weight of paniculate matter
WEIGHT GAIN
FINAL
INITIAL
LIQUID COLLECTED
TOTAL VOLUME COLLECTED
VOLUME OF LIQUID
WATER COLLECTED
IMPINGER
VOLUME.
ml
SILICA GEL
WEIGHT.
9
9* ml
'CONVERT WEIGHT OF WATER TO VOLUME BY DIVIDING TOTAL WEIGHT
INCREASE BY DENSITY OF WATER (1g/ml).
INCREASE, g
1 g/ml
= VOLUME WATER, ml
Figure 5-3. Analytical data.
-------
1-106
a difference of no more than 0.5 mg or 1 percent of total weight
less tare weight, whichever is greater, between two consecutive
weighings, with no less than 6 hours of desiccation time between
weighings.
Alternatively, the sample may be oven dried at 105°C (220°F) for
2 to 3 hours, cooled in the desiccator, and weighed to a constant
weight, unless otherwise specified by the Administrator. The tester
may also opt to oven dry the sample at 105°C (220°F) for 2 to 3 hours,
weigh the sample, and use this weight as a final weight.
Container No. 2. Note the level of liquid in the container and
confirm on the analysis sheet whether or not leakage occurred during
transport. If a noticeable amount of leakage has occurred, either void
the sample or use methods, subject to the approval of the Administrator,
to correct the final results. Measure the liquid in this container
either volumetrically to +1 ml or gravimetrically to +0.5 g. Transfer
the contents to a tared 250-ml beaker and evaporate to dryness at ambient
temperature and pressure. Desiccate for 24 hours and weigh to a
constant weight. Report the results to the nearest 0.1 mg.
Container No. 3. Weigh the spent silica gel (or silica gel plus
impinger) to the nearest 0.5 g using a balance. This step may be con-
ducted in the field.
"Acetone Blank" Container. Measure acetone in this container
either volumetrically or gravimetrically. Transfer the acetone to
a tared 250-ml beaker and evaporate to dryness at ambient temperature
and pressure. Desiccate for 24 hours and weigh to a constant weight.
Report the results to the nearest 0.1 mg.
-------
1-107
Note: At the option of the tester, the contents of Container
No. 2 as well as the acetone blank container may be evaporated at
temperatures higher than ambient. If evaporation is done at an
elevated temperature, the temperature must be below the boiling point
of the solvent; also, to prevent "bumping," the evaporation process
must be closely supervised, and the contents of the beaker must be
swirled occasionally to maintain an even temperature. Use extreme
care, as acetone is highly flammable and has a low flash point.
5. Calibration
Maintain a laboratory log of all calibrations.
5.1 Probe Nozzle. Probe nozzles shall be calibrated before
their initial use in the field. Using a micrometer, measure the
inside diameter of the nozzle to the nearest 0.025 mm (0.001 in.).
Make three separate measurements using different diameters each time,
and obtain the average of the measurements. The difference between
the high and low numbers shall not exceed 0.1 mm (0.004 in.). When
nozzles become nicked, dented, or corroded, they shall be reshaped,
sharpened, and recalibrated before use. Each nozzle shall be per-
manently and uniquely identified.
5.2 Pitot Tube. The Type S pitot tube assembly shall be calibrated
according to the procedure outlined in Section 4 of Method 2.
5.3 Metering System. Before its initial use in the field, the
metering system shall be calibrated according to the procedure outlined
in APTD-0576. Instead of physically adjusting the dry gas meter dial
readings to correspond to the v/et test meter readings, calibration
factors may be used to mathematically correct the gas meter dial readings
to the proper values. Before calibrating the-metering system, it is sug-
gested that a leak-check HP conducted. For metering systems having diaphragm
-------
1-108
pumps, the normal leak-check procedure will not detect leakages within
the pump. For these cases the following leak-check procedure is
suggested: make a 10-minute calibration run at 0.00057 m3/min (0.02 cfm);
at the end of the run, take the difference of the measured wet test meter
and dry gas meter volumes; divide the difference by 10, to get the leak
rate. The leak rate should not exceed 0.00057 m3/min (0.02 cfm).
After each field use, the calibration of the metering system
shall be checked by performing three calibration runs at a single,
intermediate orifice setting (based on the previous field test), with
the vacuum set at the maximum value reached during the test series.
To adjust the vacuum, insert a valve between the wet test meter and
the inlet of the metering system. Calculate the average value of the
calibration factor. If the calibration has changed by more than 5 per-
cent, recalibrate the meter over the full range of orifice settings, as
outlined in APTD-0576.
Alternative procedures, e.g., using the orifice meter coeffi-
cients, may be used, subject to the approval of the Administrator.
Note: If the dry gas meter coefficient values obtained before
and after a test series differ by more than 5 percent, the test
series shall either be voided, or calculations for the test series
shall be performed using whichever meter coefficient value (i.e.,
before or after) gives the lower value of total sample volume.
5.4 Probe Heater Calibration. The probe heating system shall be
calibrated before its initial use in the field according to the pro-
cedure outlined in APTD-0576. Probes constructed according to APTD-0581
need not be calibrated if the calibration curves in APTD-0576 are used.
5.5 Temperature Gauges. Use the procedure in Section 4.3 of
Method 2 to calibrate in-stack temperature gauges. Dial thermometers,
-------
1-109
such as are used for the dry gas meter and condenser outlet, shall be
calibrated against mercury-in-glass thermometers.
5.6 Leak Check of Metering System Shown in Figure 5-1. That
portion of the sampling train from the pump to the orifice meter
should be leak checked prior to initial use and after each shipment.
Leakage after the pump will result in less volume being recorded than
is actually sampled. The following procedure is suggested (see
Figure 5-4): Close the main valve on the meter box. Insert a one-
hole rubber stopper with rubber tubing attached into the orifice
exhaust pipe. Disconnect and vent the low side of the orifice manometer.
Close off the low side orifice tap. Pressurize the system to 13 to
18 cm (5 to 7 in.) water column by blowing into the rubber tubing.
Pinch off the tubing and observe the manometer for one minute. A loss
of pressure on the manometer indicates a leak in the meter box; leaks,
if present, must be corrected.
5.7 Barometer. Calibrate against a mercury barometer.
6. Calculations
Carry out calculations, retaining at least one extra decimal
figure beyond that of the acquired data. Round off figures after
the final calculation. Other forms of the equations may be used as
long as they give equivalent results.
6.1 Nomenclature.
2 2
A = Cross-sectional area of nozzle, m (ft ).
B = Water vapor in the gas stream, proportion by volume.
W o
C = Acetone blank residue concentration, mg/g.
G
c = Concentration of particulate matter in stack gas, dry
basis, corrected to standard conditions, g/dscm (g/dscf).
I = Percent of isokinetic sampling.
-------
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cn
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i-m
La = Maximum acceptable leakage rate for either a pretest
leak check or for a leak check following a component
change; equal to 0.00057 m /min (0.02 cfm) or 4 percent
of the average sampling rate, whichever is less.
L. = Individual leakage rate observed during the leak check
conducted prior to the "i " component change (1=1,
2, 3 ---- n), m /min (cfm).
L = Leakage rate observed during the post-test leak check,
o
m'/m'n (cfm).
m = Total amount of parti cul ate matter collected, mg.
M = Molecular weight of water, 18.0 g/g-mole (18.0 Ib/lb-mole).
w
m = Mass of residue of acetone after evaporation, mg.
a
P. = Barometric pressure at the sampling site, mm Hg (in. Hg).
P = Absolute stack gas pressure, mm Hg (in. Hg).
P . = Standard absolute pressure, 760 mm Hg (29.92 1n. Hg).
R = Ideal gas constant, 0.06236 mm Hg-m /°K-g-mole (21.85 in.
Hg-ft3/°R-lb-mole).
T = Absolute average dry gas meter temperature (see Figure 5-2),
°
K
T = Absolute average stack gas temperature (see Figure 5-2),
°
K
T d = Standard absolute temperature, 293°K (528°R).
V = Volume of acetone blank, ml.
3
V = Volume of acetone used in wash, ml.
aW
-------
1-112
^lc = Total volume of liquid collected in impingers and
silica gel (see Figure 5-3), ml.
V = Volume of gas sample as measured by dry gas meter,
dcm (dcf).
V / . .1= Volume of gas sample measured by the dry gas meter,
corrected to standard conditions, dscm (dscf).
V /stj\s Volume of water vapor in the gas sample, corrected to
standard conditions, scm (scf).
v = Stack gas velocity, calculated by Method 2, Equation 2-9,
using data obtained from Method 5, m/sec (ft/sec).
W = Weight of residue in acetone wash, mg.
3
Y = Dry gas meter calibration factor.
AH = Average pressure differential across the orifice meter
(see Figure 5-2), mm H^O (in. HpO).
p = Density of acetone, mg/ml (see label on bottle).
a
p = Density of water, 0.9982 g/ml (0.002201 Ib/ml).
W
e = Total sampling time, min.
e, = Sampling time interval, from the beginning of a run until
the first component change, min.
e. = Sampling time interval, between two successive component
changes, beginning with the interval between the first
and second changes, min.
e = Sampling time interval, from the final (n ) component
change until the end of the sampling run, min.
-------
1-113
13.6 = Specific gravity of mercury.
60 = Sec/min.
100 = Conversion to percent.
6.2 Average dry gas meter temperature and average orifice
pressure drop. See data sheet (Figure 5-2).
6.3 Dry Gas Volume. Correct the sample volume measured by the
dry gas meter to standard conditions (20°C, 760 mm Hg or 68°F,
29.92 in. Hg) by using Equation 5-1.
Pbar
^ ,V_Y
Vstd) = VlT
p
std
1m -.
m
Equation 5-1
where:
KI = 0.3858 °K/mm Hg for metric units
= 17.64 °R/in. Hg for English units
Note: Equation 5-1 can be used as written unless the leakage
rate observed during any of the mandatory leak checks (i.e., the
post-test leak check or leak checks conducted prior to component
changes) exceeds L . If L or 1_. exceeds L , Equation 5-1 must be
a p i a
modified as follows:
(a) Case I. No component changes made during sampling run. In
this case, replace V in Equation 5-1 with the expression:
Cy» - (LP - La> 6]
-------
1-114
(b) Case II. One or more component changes made during the
sampling run. In this case, replace V in Equation 5-1 by the
expression:
r\/ -(L - L ) 6 - i (L - L ) 6 -(L - L ) 6 1
m 1 a 1 . 2 i a i p a p
and substitute only for those leakage rates (L. or L ) which exceed
6.4 Volume of water vapor.
/, Equation 5-2
where:
1C = 0.001333 m3/ml for metric units
= 0.04707 ft3/ml for English units.
6.5 Moisture Content.
Bws = V Equation 5-3
ws Vm(std) w(std)
Note: In saturated or water droplet-laden gas streams, two
calculations of the moisture content of the stack gas shall be made,
one from the impinger analysis (Equation 5-3), and a second from the
assumption of saturated conditions. The lower of the two values of
B,,c shall be considered correct. The procedure for determining the
ws
moisture content based upon assumption of saturated conditions is
given in the Note of Section 1.2 of Method 4. For the purposes of this
method, the average stack gas temperature from Figure 5-2 may be used to
make this determination, provided that the accuracy of the in-stack
temperature sensor is +_ 1°C (2°F).
-------
1-115
6.6 Acetone Blank Concentration.
m
C = V, p, Equation 5-4
a a a
6.7 Acetone Wash Blank.
Wa = Ca Vaw pa Equation 5-5
6.8 Total Particulate Weight. Determine the total particulate
catch from the sum of the weights obtained from containers 1 and 2
less the acetone blank (see Figure 5-3). Note: Refer to Section
4.1.5 to assist in calculation of results involving two or more
filter assemblies or two or more sampling trains.
6.9 Particulate Concentration.
cs = (0.001 g/mg) (%/Vm(std)) Equation 5-6
6.10 Conversion Factors:
From Tp_ Multiply by
scf m3 0.02832
g/ft3 gr/ft3 15.43
g/ft3 lb/ft3 2.205 x 10"3
g/ft3 g/m3 35.31
6.11 Isokinetic Variation.
6.11.1 Calculation From Raw Data.
100 Ts [K3 V1c + (V, Y/TJ (Pbar + AH/13.6)]
1 =
60 6 v$ PS An
Equation 5-7
-------
1-116
where:
5
1C = 0.003454 mm Hg-m /ml-°K for metric units
= 0.002669 in. Hg-ft3/ml-°R for English units.
6.11.2 Calculation From Intermediate Values.
T Ts Vm(std) Pstd 1QO
" Tstd Vs 6 An Ps 60 n-Bws
= K4 P s )- Equati°n 5-s
s s n ws
where:
K4 = 4.320 for metric units
= 0.09450 for English units.
6.12 Acceptable Results. If 90 percent <_ I <_ 110 percent, the
results are acceptable. If the results are low in comparison to the
standard and I is beyond the acceptable range, or, if I is less than
90 percent, the Administrator may opt to accept the results. Use
Citation 4 to make judgments. Otherwise, reject the results and repeat
the test.
7. Bibliography
1. Addendum to Specifications for Incinerator Testing at Federal
Facilities. PHS, NCAPC. Dec. 6, 1967.
2. Martin, Robert M. Construction Details of Isokinetic Source-
Sampling Equipment. Environmental Protection Agency. Research
Triangle Park, N. C. APTD-0581 . April, 1971.
3. Rom, Jerome J. Maintenance, Calibration, and Operation
of Isokinetic Source Sampling Equipment. Environmental Protection
Agency. Research Triangle Park, N. C. APTD-0576. March, 1972.
-------
1-117
4. Smith, W. S., R. T. Shigehara, and W. F. Todd. A Method
of Interpreting Stack Sampling Data. Paper Presented at the
63d Annual Meeting of the Air Pollution Control Association,
St. Louis, Mo. June 14-19, 1970.
5. Smith, W. S., et al. Stack Gas Sampling Improved and
Simplified With New Equipment. APCA Paper No. 67-119. 1967.
6. Specifications for Incinerator Testing at Federal Facilities.
PHS, NCAPC. 1967.
7. Shigehara, R.T. Adjustments in the EPA Nomograph for
Different Pi tot Tube Coefficients and Dry Molecular Weights. Stack
Sampling News 2;4-11. October, 1974.
8. Vollaro, R. F. A Survey of Commercially Available Instrumentation
For the Measurement of Low-Range Gas Velocities. U. S. Environmental
Protection Agency, Emission Measurement Branch. Research Triangle
Park, N. C. November, 1976 (unpublished paper).
9. Annual Book of ASTM Standards. Part 26. Gaseous Fuels;
Coal and Coke; Atmospheric Analysis. American Society for Testing
and Materials. Philadelphia, Pa. 1974. pp. 617-622.
-------
DETERMINATION OF SULFUR DIOXIDE EMISSIONS
FROM STATIONARY SOURCES
METHOD 6
-------
-------
1-119
METHOD 6DETERMINATION OF SULFUR DIOXIDE
EMISSIONS FROM STATIONARY SOURCES
1. Principle and Applicability
1.1. Principle. A gas sample is extracted from the sampling
point in the stack. The sulfuric acid mist (including sulfur trioxide)
and the sulfur dioxide are separated. The sulfur dioxide fraction
is measured by the barium-thorin titration method.
1.2 Applicability. This method is applicable for the determina-
tion of sulfur dioxide emissions from stationary sources. The
minimum detectable limit of the method has been determined to be
3 -73
3.4 milligrams (mg) of S02/m (2.12 x 10 Ib/ft ). Although no upper
limit has been established, tests have shown that concentrations as high
3
as 80,000 mg/m of S02 can be collected efficiently in two midget impingers,
each containing 15 milliliters of 3 percent hydrogen peroxide, at a rate
of 1.0 1pm for 20 minutes. Based on theoretical calculations, the upper
concentration limit in a 20-liter sample is about 93,300 mg/m .
Possible interferents are free ammonia, water-soluble cations,
and fluorides. The cations and fluorides are removed by glass wool
filters and an isopropanol bubbler, and hence do not affect the SOp
analysis. When samples are being taken from a gas stream with high
concentrations of very fine metallic fumes (such as in inlets to
control devices), a high-efficiency glass fiber filter must be used
in place of the glass wool plug (i.e., the one in the probe) to remove
the cation interferents.
Free ammonia interferes by reacting with S02 to form particulate
sulfite and by reacting with the indicator. If free ammonia is
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present (this can be determined by knowledge of the process and
noticing white participate matter in the probe and isopropanol
bubbler), alternative methods, subject to the approval of the
Administrator, U. S. Environmental Protection Agency, are required.
2. Apparatus
2.1 Sampling. The sampling train is shown in Figure 6-1,
and component parts are discussed below. The tester has the
option of substituting sampling equipment described in Method 8
in place of the midget impinger equipment of Method 6. However, the
Method 8 train must be modified to include a heated filter between
the probe and isopropanol impinger, and the operation of the sampling
train and sample analysis must be at the flow rates and solution
volumes defined in Method 8.
The tester also has the option of determining SCL simultaneously
with particulate matter and moisture determinations by (1) replacing
the water in a Method 5 impinger system with 3 percent peroxide solution,
or (2) by replacing the Method 5 water impinger system with a Method 8
isopropanol-filter-peroxide system. The analysis for SCL must be con-
sistent with the procedure in Method 8.
2.1.1 Probe. Borosilicate glass, or stainless steel (other
materials of construction may be used, subject to the approval of
the Administrator), approximately 6-mm inside diameter, with a heating
system to prevent water condensation and a filter (either in-stack or
heated out-stack) to remove particulate matter, including sulfuric
acid mist. A plug of glass wool is a satisfactory filter.
2.1.2 Bubbler and Impingers. One midget bubbler, with
medium-coarse glass frit and borosilicate or quartz glass wool
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packed in top (see Figure 6-1) to prevent sulfuric acid mist
carryover, and three 30-ml midget impingers. The bubbler and
midget impingers must be connected in series with leak-free glass
connectors. Silicone grease may be used, if necessary, to prevent
leakage.
At the option of the tester, a midget impinger may be used
in place of the midget bubbler.
Other collection absorbers and flow rates may be used, but
are subject to the approval of the Administrator. Also, collection
efficiency must be shown to be at least 99 percent for each test run
and must be documented in the report. If the efficiency is found to
be acceptable after a series of three tests, further documentation is
not required. To conduct the efficiency test, an extra absorber must
be added and analyzed separately. This extra absorber must not contain
more than 1 percent of the total SCL.
2.1.3 Glass Wool. Borosilicate or quartz.
2.1.4 Stopcock Grease. Acetone-insoluble, heat-stable
silicone grease may be used, if necessary.
2.1.5 Temperature Gauge. Dial thermometer, or equivalent, to
measure temperature of gas leaving impinger train to within 1°C (2°F).
2.1.6 Drying Tube. Tube packed with 6- to 16-mesh indicating-
type silica gel, or equivalent, to dry the gas sample and to protect
the meter and pump. If the silica gel has been used previously, dry
at 175°C (350°F) for 2 hours. New silica gel may be used as received.
Alternatively, other types of desiccants (equivalent or better) may
be used, subject to approval of the Administrator.
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2.1.7 Valve. Needle valve, to regulate sample gas flow
rate.
2.1.8 Pump. Leak-free diaphragm pump, or equivalent, to
pull gas through the train. Install a small surge tank between the
pump and rate meter to eliminate the pulsation effect of the
diaphragm pump on the rotameter.
2.1.9 Rate Meter. Rotameter, or equivalent, capable of
measuring flow rate to within 2 percent of the selected flow rate
of about 1000 cc/min.
2.1.10 Volume Meter. Dry gas meter, sufficiently accurate to
measure the sample volume within 2 percent, calibrated at the selected
flow rate and conditions actually encountered during sampling, and
equipped with a temperature gauge (dial thermometer, or equivalent)
capable of measuring temperature to within 3°C (5.4°F).
2.1.11 Barometer. Mercury, aneroid, or other barometer
capable of measuring atmospheric pressure to within 2.5 mm Hg
(0.1 in. Hg). In many cases, the barometric reading may be obtained
from a nearby national weather service station, in which case the
station value (which is the absolute barometric pressure) shall
be requested and an adjustment for elevation differences between
the weather station and sampling point shall be applied at a rate
of minus 2.5 mm Hg (0.1 in. Hg) per 30 m (100 ft) elevation
increase or vice versa for elevation decrease.
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2.1.12 Vacuum Gauge and Rotameter. At least 760 mm Hg (30 in. Hg)
gauge and 0-40 cc/min rotameter, to be used for leak check of the sampling
train.
2.2 Sample Recovery.
2.2.1 Wash Bottles. Polyethylene or glass, 500 ml, two.
2.2.2 Storage Bottles. Polyethylene, 100 ml, to store impinger
samples (one per sample).
2.3 Analysis.
2.3.1 Pipettes. Volumetric type, 5-ml, 20-ml (one per sample),
and 25-ml sizes.
2.3.2 Volumetric Flasks. 100-ml size (one per sample) and 1000-ml
size.
2.3.3 Burettes. -5- and 50-ml sizes.
2.3.4 Erlenmeyer Flasks. 250 mi-size (one for each sample,
blank, and standard).
2.3.5 Dropping Bottle. 125-ml size, to add indicator.
2.3.6 Graduated cylinder. 100-ml size.
2.3.7 Spectrophotometer. To measure absorbance at 352 nanometers.
3. Reagents
Unless otherwise indicated, all reagents must conform to the
specifications established by the Committee on Analytical Reagents of
the American Chemical Society. Where such specifications are not
available, use the best available grade.
3.1 Sampling.
3.1.1 Water. Deionized, distilled to conform to ASTM
specification D1193-74, Type 3. At the option of the analyst,
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the KMnO. test for oxidizable organic matter may be omitted when high
concentrations of organic matter are not expected to be present.
3.1.2 Isopropanol, 80 percent. Mix 80 ml of isopropanol with 20
ml of deionized, distilled water. Check each lot of isopropanol for
peroxide impurities as follows: shake 10 ml of isopropanol with 10 ml
of freshly prepared 10 percent potassium iodide solution. Prepare a
blank by similarly treating 10 ml of distilled water. After 1 minute,
read the absorbance at 352 nanometers on a spectrophotometer (Note: Use
a 1-cm path length). If absorbance exceeds 0.1, reject
alcohol for use.
Peroxides may be removed from isopropanol by redistilling or by
passage through a column of activated alumina; however, reagent grade
isopropanol with suitably low peroxide levels may be obtained from
commercial sources.- Rejection of contaminated lots may, therefore, be a
more efficient procedure.
3.1.3 Hydrogen Peroxide, 3 Percent. Dilute 30 percent hydrogen
peroxide 1:9 (v/v) with deionized, distilled water (30 ml is needed per
sample). Prepare fresh daily.
3.1.4 Potassium Iodide Solution, 10 Percent. Dissolve 10.0
grams KI in deionized, distilled water and dilute to 100 ml. Prepare
when needed.
3.2 Sample Recovery.
3.2.1 Water. Deionized, distilled, as in 3.1.1.
3.2.2 Isopropanol, 80 Percent. Mix 80 ml of isopropanol with 20
ml of deionized, distilled water.
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3.3 Analysis.
3.3.1 Water. Deionized, distilled, as in 3.1.1.
3.3.2 Isopropanol, 100 percent.
3.3.3 Thorin Indicator. l-(o-arsonophenylazo)-2-naphthol-3,
6-disulfonic acid, disodium salt, or equivalent. Dissolve 0.20 g
in 100 ml of deionized, distilled water.
3.3.4 Barium Perchlorate Solution, 0.0100 N. Dissolve 1.95 g of
barium perchlorate trihydrate [Ba(C104)2'3H20] in 200 ml distilled water
and dilute to 1 liter with isopropanol. Alternatively, 1.22 g of
[BaCl2'2H20] may be used instead of the perchlorate. Standardize as in
Section 5.5.
3.3.5 Sulfuric Acid Standard, 0.0100 N. Purchase or standardize
to +0.0002 N against 0.0100 N NaOH which has previously been
standardized against potassium acid phthalate (primary standard
grade).
4. Procedure.
4.1 Sampling.
4.1.1 Preparation of collection train. Measure 15 ml of 80
percent isopropanol into the midget bubbler and 15 ml of 3 percent
hydrogen peroxide into each of the first two midget impingers.
Leave the final midget impinger dry. Assemble the train as shown
in Figure 6-1. Adjust probe heater to a temperature sufficient to
prevent water condensation. Place crushed ice and water around the
impingers.
4.1.2 Leak-check procedure. A leak check prior to the
sampling run is optional; however, a leak check after the sampling
run is mandatory. The leak-check procedure is as follows:
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Temporarily attach a suitable (e.g., 0-40 cc/min) rotameter to the
outlet of the dry gas meter and place a vacuum gauge at or near the
probe inlet. Plug the probe inlet, pull a vacuum of at least 250 mm Hg
(10 in. Hg), and note the flow rate as indicated by the rotameter. A
leakage rate not in excess of 2 percent of the average sampling rate is
acceptable. Note: Carefully release the probe inlet plug before
turning off the pump.
It is suggested (not mandatory) that the pump be leak-checked
separately, either prior to or after the sampling run. If done prior-to
the sampling run, the pump leak-check shall precede the leak check of
the sampling train described immediately above; if done after the
sampling run, the pump leak-check shall follow the train leak-check. To
leak check the pump, proceed as follows: Disconnect the drying tube
from the probe-impinger assembly. Place a vacuum gauge at the Inlet to
either the drying tube or the pump, pull a vacuum of 250 mm (10 in.) Hg,
plug or pinch off the outlet of the flow meter and then turn off the
pump. The vacuum should remain stable for at least 30 seconds.
Other leak-check procedures may be used, subject to the approval of
the Administrator, U.S. Environmental Protection Agency.
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4.1.3 Sample Collection. Record the initial dry gas meter reading
and barometric pressure. To begin sampling, position the tip of the
probe at the sampling point, connect the probe to the bubbler, and start
the pump. Adjust the sample flow to a constant rate of approximately
1.0 liter/min as indicated by the rotameter. Maintain this constant
rate (_+ 10 percent) during the entire sampling run. Take readings (dry
gas meter, temperatures at dry gas meter and at impinger outlet and rate
meter) at least every 5 minutes. Add more ice during the run to keep
the temperature of the gases leaving the last impinger at 20°C (68°F) or
less. At the conclusion of each run, turn off the pump, remove probe
from the stack, and record the final readings. Conduct a leak check as
in Section 4.1.2. (This' leak check is mandatory.) If a leak is found,
void the test run or use procedures acceptable to the Administrator to
adjust the sample volume for leakage. Drain the ice bath, and purge the
remaining part of the train by drawing clean ambient air through the
system for 15 minutes at the sampling rate.
Clean ambient air can be provided by passing air through a charcoal
filter or through an extra midget impinger with 15 ml of 3 percent HpO^.
The tester may opt to simply use ambient air, without purification.
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4.2 Sample Recovery. Disconnect the impingers after purging.
Discard the contents of the midget bubbler. Pour the contents of
the midget impingers into a leak-free polyethylene bottle for
shipment. Rinse the three midget impingers and the connecting
tubes with deionized, distilled water, and add the washings to
the same storage container. Mark the fluid level. Seal and
identify the sample container.
4.3 Sample Analysis. Note level of liquid in container,
and confirm whether any sample was lost during shipment; note
this on analytical data sheet. If a noticeable amount of leakage has
occurred, either void the sample or use methods, subject to the approval
of the Administrator, to correct the final results.
Transfer the contents of the storage container to a 100-ml
volumetric flask and dilute to exactly 100 ml with deionized, distilled
water. Pipette a 20-ml aliquot of this solution into a 250-ml
Erlenmeyer flask, add 80 ml of 100 percent isopropanol and two to four
drops of thorin indicator, and titrate to a pink endpoint using
0.0100 N barium perchlorate. Repeat and average the titration
volumes. Run a blank with each series of samples. Replicate
titrations must agree within 1 percent or 0.2 ml, whichever is larger.
(Note: Protect the 0.0100 N barium perchlorate solution from
evaporation at all times.)
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5. Calibration
5.1 Metering System.
5.1.1 Initial Calibration. Before its initial use in the field,
first leak check the metering system (drying tube, needle valve, pump,
rotameter, and dry gas meter) as follows: place a vacuum gauge at
the inlet to the drying tube and pull a vacuum of 250 mm (10 in.) Hg;
plug or pinch off the outlet of the flow meter, and then turn off the
pump. The vacuum shall remain stable for at least 30 seconds. Care-
fully release the vacuum gauge before releasing the flow meter end.
Next, calibrate the metering system (at the sampling flow rate
specified by the method) as follows: connect an appropriately sized
wet test meter (e.g., 1 liter per revolution) to the inlet of the
drying tube. Make three independent calibration runs, using at least
five revolutions of the dry gas meter per run. Calculate the calibra-
tion factor, Y (wet test meter calibration volume divided by the dry
gas meter volume, both volumes adjusted to the same reference temperature and
pressure), for each run, and average the results. If any Y value
deviates by more than 2 percent from the average, the metering system
is unacceptable for use. Otherwise, use the average as the calibration
factor for subsequent test runs.
5.1.2 Post-Test Calibration Check. After each field test series,
conduct a calibration check as in Section 5.1.1 above, except for the
following variations: (a) the leak check is not to be conducted, (b) three,
or more revolutions of the dry gas meter may be used, and (c) only
two Independent runs need be made. If the calibration factor does
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not deviate by more than 5 percent from the initial calibration
factor (determined in Section 5.1.1), then the dry gas meter
volumes obtained during the test series are acceptable. If the
calibration factor deviates by more than 5 percent, recalibrate
the metering system as in Section 5.1.1, and for the calculations,
use the calibration factor (initial or recalibration) that yields the
lower gas volume for each test run.
5.2 Thermometers. Calibrate against mercury-in-glass thermometers.
5.3 Rotameter. The rotameter need not be calibrated, but should
be cleaned and maintained according to the manufacturer's instruction.
5.4 Barometer. Calibrate against a mercury barometer.
5.5 Barium Perchlorate Solution. Standardize the barium perch-
lorate solution against 25 ml of standard sulfuric acid to which 100 ml
of 100 percent isopropanol has been added.
6. Calculations
Carry out calculations, retaining at least one extra decimal figure
beyond that of the acquired data. Round off figures after final calculation.
6.1 Nomenclature.
CSQ = Concentration of sulfur dioxide, dry basis corrected to
standard conditions, mg/dscm (Ib/dscf).
N = Normality of barium perchlorate titrant, mi Hi equivalents/ml.
P. = Barometric pressure at the exit orifice of the dry gas
oar
meter, mm Hg (in. Hg).
Pstd = standard absolute pressure, 760 mm Hg (29.92 in. Hg).
Tm = Avera9e dr%y 9as meter absolute temperature, °K (°R).
Tstd = standard absolute temperature, 293° K (528° R).
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V, = Volume of sample aliquot titrated, ml.
a »
V = Dry gas volume as measured by the dry gas meter, dcm
(dcf).
V / .,\ = Dry gas volume measured by the dry gas meter,
corrected to standard conditions, dscm (dscf).
V T = Total volume of solution in which the sulfur dioxide
soln
sample is contained, 100 ml.
V = Volume of barium perch!orate titrant used for the
sample, ml (average of replicate titrations).
V^. = Volume of barium perchlorate titrant used for the
tb
blank, ml.
Y = Dry gas -meter calibration factor.
32.03 = Equivalent weight of sulfur dioxide.
6.2 Dry sample gas volume, corrected to standard conditions.
V P
m bar
Equation 6-1
where:
K.J = 0.3858 °K/mm Hg for metric units.
= 17.64 °R/in. Hg for English units.
6.3 Sulfur dioxide concentration.
(/Vsoln
(V. - V,, )N\~T
Ccn = K0 rr^ - ^- Equation 6-2
bU2 2 Vm(std)
where:
Kp = 32.03 mg/meq. for metric units.
= 7.061 x 10" Ib/meq. for English units.
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7. Bibliography
1. Atmospheric Emissions from Sulfuric Acid Manufacturing
Processes. U.S. DHEW, PHS, Division of Air Pollution. Public
Health Service Publication No. 999-AP-13. Cincinnati, Ohio. 1965.
2. Corbett, P.P. The Determination of SO^ and S(L in Flue
Gases. Journal of the Institute of Fuel. 2£:237-243, 1961.
3. Matty, R. E. and E. K. Diehl. Measuring Flue-Gas S02 and
SO.. Power. l_01_:94-97. November 1957.
4. Patton, W. F. and J. A. Brink, Jr. New Equipment and
Techniques for Sampling Chemical Process Gases. J. Air Pollution
Control Association. 1_3:162. 1963.
5. Rom, J. J. Maintenance, Calibration, and Operation of
Isokinetic Source-Sampling Equipment. Office of Air Programs,
Environmental Protection Agency. Research Triangle Park, N. C.
APTD-0576. March 1972.
6. Hamil, H. F. and D. E. Camann. Collaborative Study of
Method for the Determination of Sulfur Dioxide Emissions From
Stationary Sources (Fossil-Fuel Fired Steam Generators).
Environmental Protection Agency, Research Triangle Park, N. C.
EPA-650/4-74-024. December 1973.
7. Annual Book of ASTM Standards. Part 31; Water, Atmospheric
Analysis. American Society for Testing and Materials. Philadelphia,
PA. 1974. pp. 40-42.
8. Knoll, J. E. and M. R. Midgett. The Application of EPA
Method 6 to High Sulfur Dioxide Concentrations. Environmental Protection
Agency. Research Triangle Park, N. C. EPA-600/4-76-038. July 1976.
-------
DETERMINATION OF NITROGEN OXIDE EMISSIONS
FROM STATIONARY SOURCES
METHOD?
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1-135
METHOD 7DETERMINATION OF NITROGEN OXIDE
EMISSIONS FROM STATIONARY SOURCES
1. Principle and Applicability
1.1 Principle. A grab sample is collected in an evacuated
flask containing a dilute sulfuric acid-hydrogen peroxide absorbing
solution, and the nitrogen oxides, except nitrous oxide, are
measured colorimetrically using the phenoldisulfonic acid (PDS)
procedure.
1.2 Applicability. This method is applicable to the measure-
ment of nitrogen oxides emitted from stationary sources. The range
of the method has been determined to be 2 to 400 milligrams NO (as
A
NO,,) per dry standard cubic meter, without having to dilute the sample.
2. Apparatus
2.1 Sampling (see Figure 7-1). Other grab sampling systems or
equipment, capable of measuring sample volume to within +2.0 percent
and collecting a sufficient sample volume to allow analytical reproduci-
bility to within +5 percent, will be considered acceptable alternatives,
subject to approval of the Administrator, U. S. Environmental Protection
Agency. The following equipment is used in sampling:
2.1.1 Probe. Borosilicate glass tubing, sufficiently heated to
prevent water condensation and equipped with an in-stack or out-stack
filter to remove particulate matter (a plug of glass wool is satisfactory
for this purpose). Stainless steel or Teflon tubing may also be used
for the probe. Heating is not necessary if the probe remains dry
during the purging period.
Mention of trade names or specific products does not constitute
endorsement by the Environmental Protection Agency.
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2.1.2 Collection Flask. Two-liter borosilicate, round bottom
flask, with short neck and 24/40 standard taper opening, protected
against implosion or breakage.
2.1.3 Flask Valve. T-bore stopcock connected to a 24/40
standard taper joint.
2.1.4 Temperature Gauge. Dial-type thermometer, or other
temperature gauge, capable of measuring 1°C (2°F) intervals from -5
to 50°C (25 to 125°F).
2.1.5 Vacuum Line. Tubing capable of withstanding a vacuum
of 75 mm Hg (3 in. Hg) absolute pressure, with "T" connection and
T-bore stopcock.
2.1.6 Vacuum Gauge. U-tube manometer, 1 meter (36 in.), with
1-mm (0.1-in.) divisions, or other gauge capable of measuring pressure
to within +2.5 mm Hg (0.10 in. Hg).
2.1.7 Pump. Capable of evacuating the collection flask to a
pressure equal to or less than 75 mm Hg (3 in. Hg) absolute.
2.1.8 Squeeze Bulb. One-way.
2.1.9 Volumetric Pipette. 25ml.
2.1.10 Stopcock and Ground Joint Grease. A high-vacuum, high-
temperature chlorofluorocarbon grease is required. Halocarbon 25-5S
has been found to be effective.
2.1.11 Barometer. Mercury, aneroid, or other barometer capable
of measuring atmospheric pressure to within 2.5 mm Hg (0.1 in. Hg).
In many cases, the barometric reading may be obtained from a nearby
national weather service station, in which case the station value
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(which is the absolute barometric pressure) shall be requested and
an adjustment for elevation differences between the weather station
and sampling point shall be applied at a rate of minus 2;5 mm Hg
(0.1 in. Hg) per 30 m (100 ft) elevation increase, or vice versa
for elevation decrease.
2.2 Sample Recovery. The following equipment is required for
sample recovery:
2.2.1 Graduated Cylinder. 50 ml with 1-ml divisions.
2.2.2 Storage Containers. Leak-free polyethylene bottles.
2.2.3 Wash Bottle. Polyethylene or glass.
2.2.4 Glass Stirring Rod.
2.2.5 Test Paper for Indicating pH. To cover the pH range of
7 to 14.
2.3 Analysis. For the analysis, the following equipment is needed:
2.3.1 Volumetric Pipettes. Two 1 ml, two 2 ml, one 3 ml, one
4 ml, two 10 ml, and one 25 ml for each sample and standard.
2.3.2 Porcelain Evaporating Dishes. 175- to 250-ml capacity
with lip for pouring, one for each sample and each standard. The
Coors No. 45006 (shallow-form, 195 ml) has been found to be satisfactory.
Alternatively, polymethyl pentene beakers (Nalge No. 1203, 150 ml), or
glass beakers (150 ml) may be used. When glass beakers are used, etching
of the beakers may cause solid matter to be present in the analytical
step; the solids should be removed by filtration (see Section 4.3).
2.3.3 Steam Bath. Low-temperature ovens or thermostatically
controlled hot plates kept below 70°C (160°F) are acceptable alternatives.
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2.3.4 Dropping Pipette or Dropper. Three required.
2.3.5 Polyethylene Policeman. One for each sample and each
standard.
2.3.6 Graduated Cylinder. 100 ml with 1-ml divisions.
2.3.7 Volumetric Flasks. 50 ml (one for each sample and each
standard), 100 ml (one for each sample and each standard, and one for
the working standard KNO-j solution), and 1000 ml (one).
2.3.8 Spectrophotometer. To measure absorbance at 410 nm.
2.3.9 Graduated Pipette. 10 ml with 0.1-ml divisions.
2.3.10 Test Paper for Indicating pH. To cover the pH range of 7
to 14.
2.3.11 Analytical Balance. To measure to within 0.1 mg.
3. Reagents
Unless otherwise indicated, it is intended that all reagents
conform to the specifications established by the Committee on Analytical
Reagents of the American Chemical Society, where such specifications are
available; otherwise, use the best available grade.
3.1 Sampling. To prepare the absorbing solution, cautiously add
2.8 ml concentrated H^SO. to 1 liter of deionized, distilled water. Mix
well and add 6 ml of 3 percent hydrogen peroxide, freshly prepared from
30 percent hydrogen peroxide solution. The absorbing solution should be
used within 1 week of its preparation. Do not expose to extreme heat or
direct sunlight.
3.2 Sample Recovery. Two reagents are required for sample
recovery:
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3.2.1 Sodium Hydroxide (1 N_). Dissolve 40 g NaOH in deionized,
distilled water and dilute to 1 liter.
3.2.2 Water. Deionized, distilled to conform to ASTM specifi-
cation Dll93-74, Type 3. At the option of the analyst, the KMNO. test
for oxidizable organic matter may be omitted when high concentrations
of organic matter are not expected to be present.
3.3 Analysis. For the analysis, the following reagents are
required:
3.3.1 Fuming Sulfuric Acid. 15 to 18 percent by weight free
sulfur trioxide. HANDLE WITH CAUTION.
3.3.2 Phenol. White solid.
3.3.3 Sulfuric Acid. Concentrated, 95 percent minimum assay.
HANDLE WITH CAUTION.
3.3.4 Potassium Nitrate. Dried at 105 to 110°C (220 to 230°F)
for a minimum of 2 hours just prior to preparation of standard solution.
3.3.5 Standard KN03 Solution. Dissolve exactly 2.198 g of dried
potassium nitrate (KNO-) in deionized, distilled water and dilute
to 1 liter with deionized, distilled water in a 1000-ml volumetric
flask.
3.3.6 Working Standard KNO- Solution. Dilute 10 ml of the
standard solution to 100 ml with deionized distilled water. One
mi Hi liter of the working standard solution is equivalent to 100 pg
nitrogen dioxide (NOp).
3.3.7 Water. Deionized, distilled as in Section 3.2.2.
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1-141
3.3.8 Phenoldisulfonic Acid Solution. Dissolve 25 g of pure
white phenol in 150 ml concentrated sulfuric acid on a steam bath.
Cool, add 75 ml fuming sulfuric acid, and heat at 100°C (212°F) for
2 hours. Store in a dark, stoppered bottle.
3.3.9 Concentrated Ammonium Hydroxide. Reagent grade.
4. Procedures
4.1 Sampling.
4.1.1 Pipette 25 ml of absorbing solution into a sample flask,
retaining a sufficient quantity for use in preparing the calibration
standards. Insert the flask valve stopper into the flask with the
valve in the "purge" position. Assemble the sampling train as shown
in Figure 7-1 and place the probe at the sampling point. Make sure
that all fittings are tight and leak-free, and that all ground glass
joints have been proper-ly-greased with a high-vacuum, high-temperature
chlorofluorocarbon-based stopcock grease. Turn the flask valve and the
pump valve to their "evacuate" positions. Evacuate the flask to
75 mm Hg (3 in. Hg) absolute pressure, or less. Evacuation to a
pressure approaching the vapor pressure of water at the existing
temperature is desirable. Turn the pump valve to its "vent" position
and turn off the pump. Check for leakage by observing the manometer
for any pressure fluctuation. (Any variation greater than 10 mm Hg
(0.4 in. Hg) over a period of 1 minute is not acceptable, and the
flask is not to be used until the leakage problem is corrected.
Pressure in the flask is not to exceed 75 mm Hg (3 in. Hg) absolute
at the time sampling is commenced.) Record the volume of the flask
and valve (Vf), the flask temperature (T.), and the barometric pres-
sure. Turn the flask valve counterclockwise to its "purge" position
-------
1-142
and do the same with the pump valve. Purge the probe and the vacuum
tube using the squeeze bulb. If condensation occurs in the probe
and the flask valve area, heat the probe and purge until the con-
densation disappears. Next, turn the pump valve to its "vent" position.
Turn the flask valve clockwise to its "evacuate" position and record
the difference in the mercury levels in the manometer. The absolute
internal pressure in the flask (P.) is equal to the barometric pres-
sure less the manometer reading. Immediately turn the flask valve to
the "sample" position and permit the gas to enter the flask until
pressures in the flask and sample line (i.e., duct, stack) are
equal. This will usually require about 15 seconds; a longer period
indicates a "plug" in the probe, which must be corrected before
sampling is continued. After collecting the sample, turn the flask
valve to its "purge" position and disconnect the flask from the
sampling train. Shake the flask for at least 5 minutes.
4.1.2 If the gas being sampled contains insufficient oxygen
for the conversion of NO to N0? (e.g., an applicable subpart of the
standard may require taking a sample of a calibration gas mixture of NO
in Np), then oxygen shall be introduced into the flask to permit this
conversion. Oxygen may be introduced into the flask by one of
three methods: (1) Before evacuating the sampling flask, flush
with pure cylinder oxygen, then evacuate flask to 75 mm Hg (3 in.
Hg) absolute pressure or less; or (2) inject oxygen into the flask
after sampling; or (3) terminate sampling with a minimum of 50 mm Hg
(2 in. Hg) vacuum remaining in the flask, record this final pressure,
and then vent the flask to the atmosphere until the flask pressure is
almost equal to atmospheric pressure.
-------
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4.2 Sample Recovery. Let the flask set for a minimum of 16 hours
and then shake the contents for 2 minutes. Connect the flask to a mercury
filled U-tube manometer. Open the valve from the flask to the
manometer and record the flask temperature (T^), the barometric
pressure, and the difference between the mercury levels in the
manometer. The absolute internal pressure in the flask (PJ is
the barometric pressure less the manometer reading. Transfer the
contents of the flask to a leak-free polyethylene bottle. Rinse
the flask twice with 5-ml portions of deionized, distilled water
and add the rinse water to the bottle. Adjust the pH to between 9 and
12 by adding sodium hydroxide (1 Nj, dropwise (about 25 to 35 drops).
Check the pH by dipping a stirring rod into the solution and then
touching the rod to the pH test paper. Remove as little material as
possible during this step. Mark the height of the liquid level so
that the container can be checked for leakage after transport. Label
the container to clearly identify its contents. Seal the container
for shipping.
4.3 Analysis. Note the level of the liquid in container and con-
firm whether or not any sample was lost during shipment; note this on
the analytical data sheet. If a noticeable amount of leakage has
occurred, either void the sample or use methods, subject to the approval
of the Administrator, to correct the final results. Immediately prior
to analysis, transfer the contents of the shipping container to a 50-ml
volumetric flask, and rinse the container twice with 5-ml portions of
deionized, distilled water. Add the rinse water to the flask and dilute
to the mark with deionized, distilled water; mix thoroughly. Pipette
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1-144
a 25-ml aliquot into the porcelain evaporating dish. Return any
unused portion of the sample to the polyethylene storage bottle.
Evaporate the 25-ml aliquot to dryness on a steam bath and allow to
cool. Add 2 ml phenoldisulfonic acid solution to the dried residue and
triturate thoroughly with a polyethylene policeman. Make sure the solu-
tion contacts all the residue. Add 1 ml deionized, distilled water and
four drops of concentrated sulfuric acid. Heat the solution on a
steam bath for 3 minutes with occasional stirring. Allow the solution
to cool, add 20 ml deionized, distilled water, mix well by stirring,
and add concentrated ammonium hydroxide, dropwise, with constant stirring,
until the pH is 10 (as determined by pH paper). If the sample contains
solids, these must be removed by filtration (centrifugation is an
acceptable alternative, subject to the approval of the Administrator),
as follows: filter through Whatman No. 41 filter paper into a 100-ml
volumetric flask; rinse the evaporating dish with three 5-ml portions
of deionized, distilled water; filter these three rinses. Wash the
filter with at least three 15-ml portions of deionized, distilled water.
Add the filter washings to the contents of the volumetric flask and
dilute to the mark with deionized, distilled water. If solids are
absent, the solution can be transferred directly to the 100-ml volumetric
flask and diluted to the mark with deionized, distilled water. Mix
the contents of the flask thoroughly, and measure the absorbance at
the optimum wavelength used for the standards (Section 5.2.1), using the
blank solution as a zero reference. Dilute the sample and the blank
with equal volumes of deionized, distilled water if the absorbance
exceeds A., the absorbance of the 400 ug N02 standard (see Section 5.2.2).
-------
1-145
5. Calibration
5.1 Flask Volume. The volume of the collection flask-flask valve
combination must be known prior to sampling. Assemble the flask and
flask valve and fill with water, to the stopcock. Measure the volume of
water to +10 ml. Record this volume on the flask.
5.2 Spectrophotometer Calibration.
5.2.1 Optimum Wavelength Determination. Calibrate the wavelength
scale of the spectrophotometer every 6 months. The calibration may be
accomplished by using an energy source with an intense line emission
such as a mercury lamp, or by using a series of glass filters spanning
the measuring range of the spectrophotometer. Calibration materials are
available commercially and from the National Bureau of Standards.
Specific details on the use of such materials should be supplied by the
vendor; general information about calibration techniques can be obtained
from general reference books on analytical chemistry. The wavelength
scale of the spectrophotometer must read correctly within +5 nm at all
calibration points; otherwise, the spectrophotometer shall be repaired
and recalibrated. Once the wavelength scale of the spectrophotometer is
in proper calibration, use 410 nm as the optimum wavelength for the
measurement of the absorbance of the standards and samples.
-------
1-146
Alternatively, a scanning procedure may be employed to determine
the proper measuring wavelength. If the instrument is a double-beam
spectrophotometer, scan the spectrum between 400 and 415 rim using a 200 yg
N02 standard solution in the sample cell and a blank solution in the
reference cell. If a peak does not occur, the spectrophotometer is
probably malfunctioning and should be repaired. When a peak is obtained
within the 400 to 415 nm range, the wavelength at which this peak occurs
shall be the optimum wavelength for the measurement of absorbance of
both the standards and the samples. For a single-beam spectrophotometer,
follow the scanning procedure described above, except that the blank and
standard solutions shall be scanned separately. The optimum wavelength
shall be the wavelength at which the maximum difference in absorbance
between the standard and -the blank occurs.
5.2.2 Determination-of Spectrophotometer Calibration Factor K .
Add 0.0 ml, 2.0 ml, 4.0 ml, 6.0 ml, and 8.0 ml of the KNOj working
standard solution (1 ml = 100 yg IW^) to a series of five 50-ml volumetric
flasks. To each flask, add 25 ml of absorbing solution,
10 ml deionized, distilled water, and sodium hydroxide (IN) dropwise
until the pH is between 9 and 12 (about 25 to 35 drops each). Dilute
to the mark with deionized, distilled water. Mix thoroughly and
pipette a 25-ml aliquot of each solution into a separate porcelain
evaporating dish. Beginning with the evaporation step, follow the
analysis procedure of Section 4.3, until the solution has been trans-
ferred to the 100-ml volumetric flask and diluted to the mark. Measure
the absorbance of each solution, at the optimum wavelength, as
determined in Section 5.2.1. This calibration procedure must be repeated
-------
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on each day that samples are analyzed. Calculate the spectrophotometer
calibration factor as follows:
A + 2A, + 3A, + 4A.
K = 100 -U - ^5 - z* - \ Equation 7-1
c *
where:
K = Calibration factor
A, = Absorbance of the 100-yg NOp standard
Ap = Absorbance of the 200-yg NO,, standard
A^ = Absorbance of the 300-yg N09 standard
O w
A^ = Absorbance of the 400-yg NO^ standard
5.3 Barometer. Calibrate against a mercury barometer.
5.4 Temperature Gauge. Calibrate dial thermometers against
mercury-in-glass thermometers.
5.5 Vacuum Gauge. Calibrate mechanical gauges, if used,
against a mercury manometer such as that specified in 2.1.6.
5.6 Analytical Balance. Calibrate against standard weights.
6. Calculations
Carry out the calculations, retaining at least one extra
decimal figure beyond that of the acquired data. Round off
figures after final calculations.
6.1 Nomenclature.
A = Absorbance of sample.
C = Concentration of NO as N09, dry basis, corrected to
A C
standard conditions, mg/dscm (Ib/dscf).
-------
1-148
F = Dilution factor (i.e., 25/5, 25/10, etc., required only
if sample dilution was needed to reduce the absorbance
into the range of calibration).
K = Spectrophotometer calibration factor.
m = Mass of NO as NC9 in gas sample, yg.
A C,
P. = Final absolute pressure of flask, mm Hg (in. Hg).
P. = Initial absolute pressure of flask, mm Hg (in. Hg).
Pstd = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
Tf = Final absolute temperature of flask, °K (°R).
T. = Initial absolute temperature of flask, °K (°R).
T d = Standard absolute temperature, 293°K (528°R).
V = Sample volume at standard conditions (dry basis), ml.
Vf = Volume of flask and valve, ml.
V = Volume of absorbing solution, 25 ml.
a
2 = 50/25, the aliquot factor. (If other than a 25-ml
aliquot was used for analysis, the corresponding factor
must be substituted).
6.2 Sample volume, dry basis, corrected to standard
conditions.
sc
Tstd
Pstd
-------
1-149
where:
°K
KI = 0.3858 mff) H for metric units
OR
= 17.64 -r K
. j. for English units
6.3 Total yg NO^ per sample.
m = 2«cAF Equation 7-3
Note: If other than a 25-ml aliquot is used for analysis, the
factor 2 must be replaced by a corresponding factor.
6.4 Sample concentration, dry basis, corrected to standard
conditions.
C = K2 T~ Equation 7-4
sc
where:
3
KO = 10 ^%r for metric units
2 ug/ml
= 6.243 x 10"5 for English units
7. Bibliography
1. Standard Methods of Chemical Analysis. 6th ed. New York,
D. Van Nostrand Co., Inc. 1962. Vol. 1, p. 329-330.
2. Standard Method of Test for Oxides of Nitrogen in Gaseous
Combustion Products (Phenoldisulfonic Acid Procedure). In: 1968 Book
of ASTM Standards, Part 26. Philadelphia, Pa. 1968. ASTM Designation
D-1608-60, p. 725-729.
3. Jacob, M. B. The Chemical Analysis of Air Pollutants.
New York. Interscience Publishers, Inc. 1960. Vol. 10, p. 351-356.
-------
1-150
4. Beatty, R. L., L. B. Berger, and H. H. Schrenk. Determination
of Oxides of Nitrogen by the Phenoldisulfonic Acid Method. Bureau of
Mines, U. S. Dept. of Interior. R. I. 3687. February .1943.
5. Hamil, H. F. and D. E. Camann. Collaborative Study of Method
for the Determination of Nitrogen Oxide Emissions from Stationary
Sources (Fossil Fuel-Fired Steam Generators). Southwest Research
Institute report for Environmental Protection Agency. Research Triangle
Park, N. C. October 5, 1973.
6. Hamil, H. F. and R. E. Thomas. Collaborative Study of Method
for the Determination of Nitrogen Oxide Emissions from Stationary
Sources (Nitric Acid Plants). Southwest Research Institute report for
Environmental Protection Agency. Research Triangle Park, N. C.
May 8, 1974.
-------
DETERMINATION OF SULFURIC ACID MIST AND SULFUR DIOXIDE
EMISSIONS FROM STATIONARY SOURCES
METHODS
-------
1-151
METHOD 8DETERMINATION OF SULFURIC ACID MIST AND
SULFUR DIOXIDE EMISSIONS FROM STATIONARY SOURCES
1. Principle and Applicability
1.1 Principle. A gas sample is extracted isokinetically from the
stack. The sulfuric acid mist (including sulfur trioxide) and the
sulfur dioxide are separated, and both fractions are measured separately
by the barium-thorin titration method.
1.2 Applicability. This method is applicable for the determi-
nation of sulfuric acid mist (including sulfur trioxide, and in the
absence of other particulate matter) and sulfur dioxide emissions from
stationary sources. Collaborative tests have shown that the minimum
detectable limits of the method are 0.05 milligrams/cubic meter (0.03
-7 3 -7
x 10" pounds/cubic foot) for sulfur trioxide and 1.2 mg/m (0.74 x 10
2
Ib/ft ) for sulfur .dioxide. No upper limits have been established.
Based on theoretical calculations for 200 milliliters of 3 percent
hydrogen peroxide solution, the upper concentration limit for sulfur
dioxide in a 1.0 m (35.3 ft ) gas sample is about 12,500 mg/m3 (7.7 x
10" Ib/ft ). The upper limit can be extended by increasing the
quantity of peroxide solution in the impingers.
Possible interfering agents of this method are fluorides, free
ammonia, and dimethyl aniline. If any of these interfering agents are
present (this can be determined by knowledge of the process), alterna-
tive methods, subject to the approval of the Administrator,
U. S. Environmental Protection Agency, are required.
-------
1-152
Filterable particulate matter may be determined along with S03 and
S02 (subject to the approval of the Administrator) by inserting a heated
glass fiber filter between the probe and isopropanol impinger (see
Section 2.1 of Method 6). If this option is chosen, participate
analysis is gravimetric only; H^SCh acid mist is not determined separately.
2. Apparatus
2.1 Sampling. A schematic of the sampling train used in this
method is shown in Figure 8-1; it is similar to the Method 5 train
except that the filter position is different and the filter holder does
not have to be heated. Commercial models of this train are available.
For those who desire to build their own, however, complete construction
details are described in APTD-0581. Changes from the APTD-0581 document
and allowable modifications to Figure 8-1 are discussed in the following
subsections.
The operating and maintenance procedures for the sampling train are
described in APTD-0576. Since correct usage is important in obtaining
valid results, all users should read the APTD-0576 document and adopt
the operating and maintenance procedures outlined in it, unless otherwise
specified herein. Further details and guidelines on operation and
maintenance are given in Method 5 and should be read and followed
whenever they are applicable.
2.1.1 Probe Nozzle. Same as Method 5, Section 2.1.1.
2.1.2 Probe Liner. Borosilicate or quartz glass, with a heating
system to prevent visible condensation during sampling. Do not use
metal probe liners.
2.1.3 Pitot Tube. Same as Method 5, Section 2.1.3.
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-------
1-154
2.1.4 Differential Pressure Gauge. Same as Method 5, Section
2.1.4.
2.1.5 Filter Holder. Borosilicate glass, with a glass frit
filter support and a silicone rubber gasket. Other gasket materials,
e.g., Teflon or Viton, may be used subject to the approval of the
Administrator. The holder design shall provide a positive seal against
leakage from the outside or around the filter. The filter holder shall
be placed between the first and second impingers. Note: Do not heat
the filter holder.
2.1.6 Impingers--Four, as shown in Figure 8-1. The first and
third shall be of the Greenburg-Smith design with standard tips. The
second and fourth shall be of the Greenburg-Smith design, modified by
replacing the insert with an approximately 13 millimeter (0.5 in.)
ID glass tube, having an unconstricted tip located 13 mm (0.5 in.)
from the bottom of the flask. Similar collection systems, which have
been approved by the Administrator, may be used.
2.1.7 Metering System. Same as Method 5, Section 2.1.8.
2.1.8 Barometer. Same as Method 5, Section 2.1.9.
2.1.9 Gas Density Determination Equipment. Same as Method 5,
Section 2.1.10.
2.1.10 Temperature Gauge. Thermometer, or equivalent, to measure
the temperature of the gas leaving the impinger train to within 1°C
(2°F).
2.2 Sample Recovery.
2.2.1 Wash Bottles. Polyethylene or glass, 500 ml. (two).
2.2.2 Graduated Cylinders. 250ml, 1 liter. (Volumetric flasks
may also be used.)
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1-155
2.2.3 Storage Bottles. Leak-free polyethylene bottles,
1000 ml size (two for each sampling run).
2.2.4 Trip Balance. 500-gram capacity, to measure to +0.5 g
(necessary only if a moisture content analysis 1s to be done).
2.3 Analysis.
2.3.1 Pipettes. Volumetric 25ml, 100ml.
2.3.2 Burette. 50 ml.
2.3.3 Erlenmeyer Flask. 250 ml. (one for each sample blank
and standard).
2.3.4 Graduated Cylinder. 100ml.
2.3.5 Trip Balance. 500 g capacity, to measure to +0.5 g.
2.3.6 Dropping Bottle. To add indicator solution, 125-ml size.
3. Reagents
Unless otherwise indicated, all reagents are to conform to the
specifications established by the Committee on Analytical Reagents of
the American Chemical Society, where such specifications are available.
Otherwise, use the best available grade.
3.1 Sampling.
3.1.1 Filters. Same as Method 5, Section 3.1.1.
3.1.2 Silica Gel. Same as Method 5, Section 3.1.2.
3.1.3 Water. Deionized, distilled to conform to ASTM specification
Dll93-74, Type 3. At the option of the analyst, the KMnO^ test for
oxidizable organic matter may be omitted when high concentrations of
organic matter are not expected to be present.
-------
1-156
3.1.4 Isopropanol, 80 Percent. Mix 800 ml of isopropanol with 200
ml of deiom'zed, distilled water.
Note: Experience has shown that only A.C.S. grade isopropanol is
satisfactory. Tests have shown that isopropanol obtained from commercial
sources occasionally has peroxide impurities that will cause erroneously
high suIfuric acid mist measurement. Use the following test for
detecting peroxides in each lot of isopropanol: Shake 10 ml of the
isopropanol with 10 ml of freshly prepared 10 percent potassium iodide
solution. Prepare a blank by similarly treating 10 ml of distilled
water. After 1 minute, read the absorbance on a spectrophotometer at
352 nanometers (Note: Use a 1 cm path length). If the absorbance
exceeds 0.1, the isopropanol shall not be used. Peroxides may be removed
from isopropanol by redistilling, or by passage through a column of
activated alumina. However, reagent-grade isopropanol with suitably low
peroxide levels is readily available from commercial sources; therefore,
rejection of contaminated lots may be more efficient than following the
peroxide removal procedure.
3.1.5 Hydrogen Peroxide, 3 Percent. Dilute 100 ml of 30 percent
hydrogen peroxide to 1 liter with deionized, distilled water. Prepare
fresh daily.
3.1.6 Crushed Ice.
3.2 Sample Recovery.
3.2.1 Water. Same as 3.1.3.
3.2.2 Isopropanol, 80 Percent. Same as 3.1.4.
3.3 Analysis.
3.3.1 Water. Same as 3.1.3.
-------
1-157
3.3.2 Isopropanol, 100 Percent.
3.3.3 Thorin Indicator. l-(o-arsonophenylazo)-2-naphthol-3,
6-disulfonic acid, disodium salt, or equivalent. Dissolve 0.20 g
in 100 ml of deionized, distilled water.
3.3.4 Barium Perchlorate (0.0100 Normal). Dissolve 1.95 g of
barium perchlorate trihydrate (BalClO.L-SHpO) in 200 ml deionized,
distilled water, and dilute to 1 liter with isopropanol; 1.22 g of
barium chloride dihydrate (BaCU^HpO) may be used instead of the
barium perchlorate. Standardize with sulfuric acid as in Section 5.2.
This solution must be protected against evaporation at all times.
3.3.5 Sulfuric Acid Standard (0.0100 N). Purchase or standardize
to +0.0002 N against 0.0100 N NaOH that has previously been standardized
against primary standard potassium acid phthalate.
4. Procedure
4.1 Sampling.
4.1.1 Pretest Preparation. Follow the procedure outlined in
Method 5, Section 4.1.1; filters should be inspected, but need not be
desiccated, weighed, or identified. If the effluent gas can be
considered dry, i.e., moisture free, the silica gel need not be weighed.
4.1.2 Preliminary Determinations. Follow the procedure outlined
in Method 5, Section 4.1.2.
4.1.3 Preparation of Collection Train. Follow the procedure
outlined in Method 5, Section 4.1.3 (except for the second paragraph
and other obviously inapplicable parts) and use Figure 8-1 instead of
Figure 5-1. Replace the second paragraph with: Place 100 ml of
-------
1-158
80 percent isopropanol in the first impinger, 100 ml of 3 percent
hydrogen peroxide in both the second and third impingers; retain a
portion of each reagent for use as a blank solution. Place about
200 g of silica gel in the fourth impinger.
Note: If moisture content is to be determined by impinger analysis,
weigh each of the first three impingers (plus absorbing solution) to
the nearest 0.5 g and record these weights. The weight of the silica
gel (or silica gel plus container) must also be determined to the nearest
0.5 g and recorded.
4.1.4 Pretest Leak-Check Procedure. Follow the basic procedure
outlined in Method 5, Section 4.1.4.1, noting that the probe heater
shall be adjusted to the minimum temperature required to prevent
condensation, and also that verbage such as, ". . . plugging the
inlet to the filter holder . . . ," shall be replaced by, ". . . plugging
the inlet to the first impinger . . . ." The pretest leak-check is
optional.
4.1.5 Train Operation. Follow the basic procedures outlined in
Method 5, Section 4.1.5, in conjunction with the following special
instructions. Data shall be recorded on a sheet similar to the one
in Figure 8-2. The sampling rate shall not exceed 0.030 m /min
(1.0 cfm) during the run. Periodically during the test, observe the
connecting line between the probe and first impinger for signs of
condensation. If it does occur, adjust the probe heater setting
upward to the minimum temperature required to prevent condensation.
If component changes become necessary during a run, a leak-check shall
-------
1-159
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be done immediately before each change, according to the procedure
outlined in Section 4.1.4.2 of Method 5 (with appropriate modifica-
tions, as mentioned in Section 4.1.4 of this method); record all
leak rates. If the leakage rate(s) exceed the specified rate, the
tester shall either void the run or shall plan to correct the sample
volume as outlined in Section 6.3 of Method 5. Immediately after
component changes, leak-checks are optional. If these leak-checks
are done, the procedure outlined in Sp-.tion 4.1.4.1 of Method 5
(with appropriate modifications) shall be used.
After turning off the pump and recording the final readings at
the conclusion of each run, remove the probe from the stack. Conduct
a post-test (mandatory) leak-check as in Section 4.1.4.3 of Method 5
(with appropriate modifications) and record the leak rate. If the
post-test leakage rate exceeds the specified acceptable rate, the
tester shall either correct the sample volume, as outlined in
Section 6.3 of Method 5, or shall void the run.
Drain the ice bath and, with the probe disconnected, purge the
remaining part of the train, by drawing clean ambient air through the
system for 15 minutes at the average flow rate used for sampling.
Note: Clean ambient air can be provided by passing air through
a charcoal filter. At the option of the tester, ambient air (without
cleaning) may be used.
4.1.6 Calculation of Percent Isokinetic. Follow the procedure
outlined in Method 5, Section 4.1.6.
-------
1-161
4.2 Sample Recovery.
4.2.1 Container No. 1. If a moisture content analysis is to
be done, weigh the first impinger plus contents to the nearest 0.5 g
and record this weight.
Transfer the contents of the first impinger to a 250-ml graduated
cylinder. Rinse the probe, first impinger, all connecting glassware
before the filter, and the front half of the filter holder with 80 per-
cent isopropanol. Add the rinse solution to the cylinder. Dilute to
250 ml with 80 percent isopropanol. Add the filter to the solution,
mix, and transfer to the storage container. Protect the solution against
evaporation. Mark the level of liquid on the container and identify the
sample container.
4.2.2 Container No. 2. If a moisture content analysis is to be
done, weigh the second and third impingers (plus contents) to the nearest
0.5 g and record these weights. Also, weigh the spent silica gel (or
silica gel plus impinger) to the nearest 0.5 g.
Transfer the solutions from the second and third impingers to a
1000-ml graduated cylinder. Rinse all connecting glassware (including
back half of filter holder) between the filter and silica gel impinger
with deionized, distilled water, and add this rinse water to the cylinder.
Dilute to a volume of 1000 ml with deionized, distilled water. Transfer
the solution to a storage container. Mark the level of liquid on the
container. Seal and identify the sample container.
4.3 Analysis.
Note the level of liquid in containers 1 and 2, and confirm whether
or not any sample was lost during shipment; note this on the analytical
data sheet. If a noticeable amount of leakage has occurred, either void
the sample or use methods, subject to the approval of the Administrator,
to correct the final results.
-------
1-162
4.3.1 Container No. 1. Shake the container holding the
isopropanol solution and the filter. If the filter breaks up,
allow the fragments to settle for a few minutes before removing
a sample. Pipette a 100-ml aliquot of this solution into a 250-ml
Erlenmeyer flask, add 2 to 4 drops of thorin indicator, and titrate
to a pink endpoint using 0.0100 N barium perchlorate. Repeat the
titration with a second aliquot of sample and average the titration
values. Replicate titrations must agree within 1 percent or 0.2 ml,
whichever is greater.
4.3.2 Container No. 2. Thoroughly mix the solution in the
container holding the contents of the second and third impingers.
Pipette a 10-ml aliquot of sample into a 250-ml Erlenmeyer flask.
Add 40 ml of isopropanol, 2 to 4 drops of thorin indicator, and
titrate to a pink endpoint using 0.0100 N barium perchlorate. Repeat
the titration with a second aliquot of sample and average the titration
values. Replicate titrations must agree within 1 percent or 0.2 ml,
whichever is greater.
4.3.3 Blanks. Prepare blanks by adding 2 to 4 drops of thorin
indicator to 100 ml of 80 percent isopropanol. Titrate the blanks in
the same manner as the samples.
5. Calibration
5.1 Calibrate equipment using the procedures specified in the
following sections of Method 5: Section 5.3 (metering system); Section 5.5
(temperature gauges); Section 5.7 (barometer). Note that the recommended
leak-check of the metering system, described in Section 5.6 of Method 5,
also applies to this method.
5.2 Standardize the barium perchlorate solution with 25 ml of
standard sulfuric acid, to which 100 ml of 100 percent isopropanol has
been added.
-------
1-163
6. Calculations
Note: Carry out calculations retaining at least one extra
decimal figure beyond that of the acquired data. Round off figures
after final calculation.
6.1 Nomenclature.
2 2
A = Cross-sectional area of nozzle, m (ft ).
B = Water vapor in the gas stream, proportion by volume.
C,, cn = Sulfuric acid (including S00) concentration, g/dscm
H2bU4 6
(Ib/dscf).
CSQ = Sulfur dioxide concentration, g/dscm (Ib/dscf).
I = Percent of isokinetic sampling.
N = Normality of barium perchlorate titrant, g equivalents/
liter.
P. = Barometric pressure at the sampling site, mm Hg (in. Hg)
P = Absolute stack gas pressure, mm Hg (in. Hg).
P d = Standard absolute pressure, 760 mm Hg (29.92 in. Hg).
T = Average absolute dry gas meter temperature (see
Figure 8-2), °K (°R).
T = Average absolute stack gas temperature (see Figure 8-2),
°K (°R).
Tstd = standard absolute temperature, 293°K (528°R).
Vfl = Volume of sample aliquot titrated, 100 ml for HpSO,
and 10 ml for S0?.
Vlc = Total volume of liquid collected in impingers and
silica gel, ml.
-------
1-164
V s Volume of gas sample as measured by .dry gas meter,
dcm (dcf).
V / td)= Volume of gas sample measured by the dry gas meter
corrected to standard conditions, dscm (dscf).
v = Average stack gas velocity, calculated by Method 2,
Equation 2-9, using data obtained from Method 8,
m/sec (ft/sec).
V , = Total volume of solution in which the sulfuric acid
soln
or sulfur dioxide sample is contained, 250 ml or
1000 ml, respectively.
V. = Volume of barium perchlorate titrant used for the
sample, ml.
V^. = Volume of barium perchlorate titrant used for the
tb
blank, ml.
Y - Dry gas meter calibration factor.
AH = Average pressure drop across orifice meter, mm (in.)
H20.
8 - Total sampling time, min.
13.6 = Specific gravity of mercury.
60 = sec/min.
100 = Conversion to percent.
6.2 Average dry gas meter temperature and average orifice
pressure drop. See data sheet (Figure 8-2).
6.3 Dry Gas Volume. Correct the sample volume measured by
the dry gas meter to standard conditions (20°C and 760 mm Hg or
68°F and 29.92 in. Hg) by using Equation 8-1.
-------
1-165
Pbar * (T> . K Y * "H/13'6)
-- KlV
Equation 8-1
where:
KI = 0.3858 °K/mm Hg for metric units".
= 17.64 °R/in. Hg for English units.
Note: If the leak rate observed during any mandatory leak-checks
exceeds the specified acceptable rate, the tester shall either correct
the value of V in Equation 8-1 (as described in Section 6.3 of
Method 5), or shall invalidate the test run.
6.4 Volume of Water Vapor and Moisture Content. Calculate the
volume of water vapor using Equation 5-2 of Method 5; the weight of
water collected in the impingers and silica gel can be directly
converted to milliliters (the specific gravity of water is 1 g/ml).
Calculate the moisture content of the stack gas, using Equation 5-3
of Method 5. The "Note" in Section 6.5 of Method 5 also applies to
this method. Note that if the effluent gas stream can be considered
dry, the volume of water vapor and moisture content need not be calcu-
lated.
6.5 Sulfuric acid mist (including SO-) concentration.
N (V. - V.,) , -nn-
Cu ,n = K9 l tD \ va / Equation 8-2
74 *- \i
2 4 Vm(std)
where:
K2 = 0.04904 g/mi Hi equivalent for metric units.
= 1.081 x 10"4 Ib/meq for English units.
-------
1-166
6.6 Sulfur dioxide concentration
N f\i _ v ) I _
H ^Vt vtb; I V
Ccn = K, n Equation 8-3
bU2 J m(std)
where:
K- = 0.03203 g/meq for metric units.
-5
= 7.061 x 10 Ib/meq for English units.
6.7 Isokinetic Variation.
6.7.1 Calculation from raw data.
(VmY/Tm) (Pfc.. + AH/13.6)]
60 e v P An
Equation 8-4
where:
K4 = 0.003464 mm Hg-m3/ml-°K for metric units.
= 0.002676 in. Hg-ft3/ml-°R for English units.
6.7.2 Calculation from intermediate values.
Ts Vstd) pstd
Tstd vs * An 60
K
5 Ps y
where:
Kc = 4.320 for metric units.
o
= 0.09450 for English units.
-------
1-167
6.8 Acceptable Results. If 90 percent <_ I <_ 110 percent,
the results are acceptable. If the results are low in comparison
to the standards and I is beyond the acceptable range, the
Administrator may opt to accept the results. Use Citation 4 in
the Bibliography of Method 5 to make judgments. Otherwise, reject
the results and repeat the test.
7. Bibliography
1. Atmospheric Emissions from Sulfuric Acid Manufacturing
Processes. U. S. DHEW, PHS, Division of Air Pollution. Public
Health Service Publication No. 999-AP-13. Cincinnati, Ohio. 1965.
2. Corbett, P. F. The Determination of SO,, and S03 in Flue
Gases. Journal of the Institute of Fuel. 24_:237-243. 1961.
3. Martin, Robert M. Construction Details of Isokinetic
Source Sampling Equipment. Environmental Protection Agency. Research
Triangle Park, N. C. Air Pollution Control Office Publication No.
APTD-0581. April, 1971.
4. Patton, W. F. and J. A. Brink, Jr. New Equipment and
Techniques for Sampling Chemical Process Gases. Journal of Air
Pollution Control Association. 1_3:162. 1963.
5. Rom, J. J. Maintenance, Calibration, and Operation of
Isokinetic Source-Sampling Equipment. Office of Air Programs,
Environmental Protection Agency. Research Triangle Park, N. C.
APTD-0576. March, 1972.
6. Hamil, H. F. and D. E. Camann. Collaborative Study of
Method for Determination of Sulfur Dioxide Emissions from Stationary
-------
1-168
Sources (Fossil Fuel-Fired Steam Generators). Environmental Protection
Agency. Research Triangle Park, N. C. EPA-650/4-74-024. December,
1973.
7. Annual Book of ASTM Standards. Part 31; Water, Atmospheric
Analysis, pp. 40-42. American Society for Testing and Materials.
Philadelphia, Pa. 1974.
-------
FIELD DATASHEETS
PART II
-------
TRAVERSE POINT LOCATION FOR CIRCULAR DUCTS
PLANT
DATE
SAMPLING LOCATION
INSIDE OF FAR WALL TO
OUTSIDE OF NIPPLE, (DISTANCE Ai _
INSIDE OF NEAR WALL TO
OUTSIDE OF NIPPLE, (DISTANCE B) _
STACK I.D., (DISTANCE A - DISTANCE B).
NEAREST UPSTREAM DISTURBANCE
NEAREST DOWNSTREAM DISTURBANCE _
CALCULATOR
SCHEMATIC OF SAMPLING LOCATION
TRAVERSE
POINT
NUMBER
FRACTION
OF STACK I.D.
STACK I.D.
PRODUCT OF
COLUMNS 2 AND 3
(TO NEAREST 1 '8 INCH)
DISTANCE B
TRAVERSE POINT LOCATION
FROM OUTSIDE OF NIPPLE
(SUM OF COLUMNS 4 & 5)
II-l
-------
METHOD 2 GAS VELOCITY AND VOLUME DATA
PLANT AND CITY
RUN DATE
I
/
I
/
I
SAMPLING LOCATION
CLOCK
TIME
RUN
NUMBER
OPERATOR
AMB . TEMP .
(°F)
BAR. PRESS
(in. Hg)
STATIC PRESS
(in. H20)
MOLECULAR
WT.
i i i i
STACK INSIDE DIMENSION (in.)
DIAM OR SIDE 1
i i i i i
SIDE 2
i i i i i _.
PITOT
TUBE Cp
t i i
FIELD DATA
TRAVERSE
POINT
NUMBER
POSITION
(in.)
VELOCITY
HEAD
(Ap ),
in. H20
STACK
TEMP. , CF
CYCLONIC FLOW DETERMINATION
Ap at
0° REFERENCE
AVERAGE ANGLE (=)
ANGLE (oc)
WHICH YIELDS
A NULL Ap
Average of ( a) must be less than 10 degrees to be acceptable.
II-2
-------
METHOD 2 PITOT TUBE CALIBRATION
PITOT TUBE IDENTIFICATION NUMBER:.
CALIBRATED BY:
DATE:.
RUN NO.
1
2
3
"A" SIDE CALIBRATION
APstd
em H20
(in. H20)
*P(s)
cm H20
(in. H20)
AVERAGE
CP(SJ
DEV.
RUN NO.
1
2
3
"B" SIDE CALIBRATION"
Apstd
em HpO
|m.H20)
*P(s)
cm H20
(in. H20)
AVERAGE
CP(S)
OEV.
DEV.- .Cp(S)-Cp(s)(avq.) (MUST BE £0.01)
Cp DIFFERENCE: Aavg-Bavj* (MUST BE £ 0.01)
NOTE: Not required if pitot tube
meets geometry standards.
II-3
-------
Date
Integrated Bag Sampling Field Data
Run No.
Plant
Sampling location
Barometric pressure
Ambient temp. °F
Operator
11 Hg.
Stack temp. °F
Sample bag leak checked
Sample train leak checked
Time
Traverse
point
Rate weter
flow rate,
Q cm /min.
Average
n _ n
% Dev.a
Fyrite,
°2
co2
% Dev. = (-
-) 100
II-4
(Must be -10%)
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-------
METHOD 5
PARTICULATE SAMPLE RECOVERY AND INTEGRITY SHEET
Plant: Sample date:
Sample location: Run no.:
Sample recovery person: Recovery date:
Filter (s) no.:
MOISTURE
Impingers Silica gel
Final volume (wt) ml (gm) Final wt.
Initial volume (wt) ml(gm) Initial wt.
Net volume (wt) ml (gm) Net wt.
Total moisture
Color of silica gel
Description of impinger water
RECOVERED SAMPLE
Filter container no. sealed
Description of particulate on filter
Acetone rinse Liquid level
container no. marked
Acetone blank Liquid level
container no. marked
Samples stored and locked
Remarks:
Date of laboratory custody
Laboratory personnel taking custody
Remarks:
II-8
-------
BLANK ANALYTICAL DATA
Plant
Sample location
Relative humidity
Type of blank
Liquid level at mark and container sealed
Density of blank (pa)
Blank volume (Va)
Date and time of wt.
Date and time of wt.
ml
Gross wt.
Gross wt.
Average gross wt.
Tare wt.
Weight of blank (ma)
Ca =
ma
Va pa
T(
mg
mg
mg
mg
mg
Note: In no case shall a blank residue greater than (0.01
mg/g) or 0.001% of the weight of blank used be subtracted
from the sample weight.
Remarks:
Signature of analyst
Signature of reviewer
II-9
-------
METHOD 5 TRAIN ANALYTICAL PARTICULATE DATA
Plant
Sample location
Relative humidity
Density of acetone (pa)
Run No.
g/ml
Sample
type
Acetone rinse
filter (s)
Sample
identifiable
Liquid level marked
and/or container sealed
Acetone rinse container no.
Acetone rinse volume (Vaw)
ml
Acetone blank residue concentration (Ca)
Wa = Ca Vaw pa = (
Date and time of wt
Date and
Filter (s)
Date and
Date and
time of wt
Weight of
container
time of wt
time of wt
Weight
Weight of
) ( ) ( ) =
Gross wt
Gross wt
Average gross wt
Tare wt
Less acetone blank wt (Wa)
particulate in acetone rinse
no .
Gross wt
Gross wt
Average gross wt
Tare wt
of particulate on filter (s)
particulate in acetone rinse
Total weight of particulate
mg/g
mg
mg
mg
mg
mg
mg
mg
mg
mg
mg
mg
mg
mg
mg
Note: In no case shall a blank residue greater than (.01 mg/g) or
.001% of the weight of acetone used be subtracted from the sample
weight.
Remarks:
Signature of analyst
Signature of reviewer
11-10
-------
Date
NOZZLE CALIBRATION
Calibrated by
Nozzle
identification
number
D-j^, in.
Dp, in.
D.,, in.
AD, in.
D
avg
where :
D-, .. = nozzle diameter measured on a different diameter, in.
' ' ' Tolerance = measure within 0.001 in.
AD = maximum difference in any two measurements, in.
Tolerance = 0.004 in.
D
avg
= average of D,, D_, and D_,
Nozzle calibration data.
11-11
-------
CALIBRATION
DRY GAS METER & ORIFICE
DATE
BAROMETRIC PRESSURE, Pfa
METER BOX NO.
.in. Hg.
DRY GAS METER NO.
Orifice
manometer
setting
AH
in. H20
0.5
1.0
1.5
2.0
3.0
4.0
Gas volume
wettest
meter
V
ft3
5
5
10
10
10
10
Gas volume
dry gas
meter
V
ft3
Wet test
Meter
V
°F
Dry gas meter
Inlet
V
°F
Outlet
V
°F
Average
V
°F
Time
e,
min.
Y
AH@
Average
AH
0.5
1.0
1.5
2.0
3.0
4.0
AH
13.6
0.0368
0.0737
0.110
0.147
0.221
0.294
Y
Vw Pb
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11-13
-------
Date:
Thermocouple No.:
Ambient Temperature:.
Calibrator:
°C Barometric pressure:
." Hg
Reference: Mercury-in-glass:
Other:_
Reference
point
No.a
Source
(specify)
Reference
thermometer
temperature,
°C
Thermocouple
potentiometer
temperature,
°C
Q
Difference ,
%
, Every 30°C (50°F) for each reference point
Type of Calibration system used
(Ref. temp; "C + 273) - (Test therm, temp.
Ref. temp. CC + 273
>C + 273)
x 100<1.5%
Stack Temperature Sensor Calibration Data Sheet
11-14
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11-15
-------
PLANT
METHOD 6 SAMPLE RECOVERY AND INTEGRITY DATA
SAMPLE LOCATION
FIELD DATA CHECKS
SAMPLE RECOVERY PERSONNEL
PERSON WITH DIRECT RESPONSIBILITY FOR RECOVERED SAMPLES
Sample
no.
1
2
3
4
5
6
Blank
Sample
identification
no.
Date of
recovery
Liquid
level
marked
Stored
in locked
container
REMARKS
SIGNATURE OF FIELD SAMPLE TRUSTEE
LABORATORY DATA CHECKS
LAB PERSON WITH DIRECT RESPONSIBILITY FOR RECOVERED SAMPLES
DATE RECOVERED SAMPLES RECEIVED
ANALYST
Sample
no.
1
2
3
4
5
6
Blank
Sample
identification
no.
Date of
analysis
Liquid
at marked
level
Sample
identified
REMARKS
SIGNATURE OF LAB SAMPLE TRUSTEE
11-16
-------
METHOD 6
SULFUR DIOXIDE ANALYTICAL DATA
PLANT
DATE
E LOCATION ANALYST
LITY OF
1
BARIUM PERCHLORATE 2
3
ml N
ml N N
ml N
Run
No.
1
2
3
4
5
6
Sample
No.
Total
Volume
of Sample
Sample
Aliquot
Volume of Titrant V , ml
1st
Titration
2nd
Titration
Average
Blank Analysis - Volume of titrant 1st titration.
2nd titration.
Average
1st titration
2nd titration
= 0.99 to 1.01 or 1st titration - 2nd titration = 0.2 i
Signature of Analyst
Signature of Reviewer or Supervisor.
11-17
-------
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Plant
Date
Sample Recovery Personnel
Barometric Pressure, (P )
ba r -
in. Hg
Person with direct responsibility for recovered samples
Sample
No.
Final Pressure
in. Hg
Leq Af
Leq Bf
P£
Final Temperature
*F
-------
NOX LABORATORY DATA FORM
Plant
Date samples received
Aliquot factor
Blank absorbance
Calibration factor (KC>
Run No. (B)
Date analyzed
Samples analyzed by
Data reviewed by
Date of review
Sample
No.
Sample
absorbance
A
Dilution
factor
F
Total mass of NO
at NO, in sample*
tn
2 K AT, Note: If other than a 25 ml aliquot ia used for analysis, the factor
2 must be replaced by a corresponding factor.
METHOD 7 ANALYTICAL DATA SHEET
11-20
-------
OPTIMUM WAVELENGTH DETERMINATION1
^^ectrophotometer No.
Calibrated by
Date
Reviewed by
Spec tropho tome ter
setting, nm
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
»415
416
Absorbance
of standard
ODa
Absorbance
of blank
ODb
Actual
absorbance of
ODC
Absorbance of the 200 pg N02 standard in a single beam
spectrophotometer.
a single beam spectrophoto-
Absorbance of the blank in
meter.
For a single beam spectrophotometer - absorbance of the
standard minus absorbance of the blank. For a double
beam spectrophotometer - absorbance of the 200 yg NO2
standard with the blank in the reference cell.
Spectrophotometer setting for maximum actual absorbance
of standard (nm)
I » » i i -*' .1 ..,.i . ^a.
If the maximum actual absorbance occurs at a spectrophotometer setting
of 399 or 416 nm, the spectrophotometer must be repaired or
recalibrated.
METHOD 7 Optimum Wavelength Determination Data Sheet.
11-21
-------
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11-22
-------
PLANT_
SAMPLE LOCATION.
FIELD DATA CHECKS
SAMPLE RECOVERY PERSONNEL
PERSON WITH DIRECT RESPONSIBILITY FOR RECOVERED SAMPLES.
Sample
no.
1
2
3
BLANKS
Sample
identification
no.
H2S04
so2
Date of
recovery
Liquid
level
marked
Stored
in locked
container
REMARKS
SIGNATURE OF FIELD SAMPLE TRUSTEE
LABORATORY DATA CHECKS
PERSON WITH DIRECT RESPONSIBILITY FOR RECOVERED SAMPLES.
DATE RECOVERED SAMPLES RECEIVED
ANALYST
Sample
no.
1
2
3
BLANKS
Sample
identification
no.
H2S04
so2
Date of
analysis
Liquid
at marked
level
Sample
identified
REMARKS
SIGNATURE OF LAB SAMPLE TRUSTEE
METHOD 8 Sample recovery and integrity data.
11-23
-------
PLANT
SAMPLE LOCATION
DATE
ANALYST
1.
NORMALITY OF BARIUM PERCHLORATE 2.
3.
ml Ba(C104)2
ml Ba(C104)2 N(Avg
ml Ba(C104J2
SULFURIC ACID MIST (INCLUDING SULFUR TRIOXIDE) ANALYSIS
V , - Total volume of solution in which the
so n sulfuric acid sample is contained, ml
V - Volume of sample aliquot, ml
a
V - Volume of barium perchlorate 1st titration
titrant used for sample, ml 2nd titration
Average
V - Volume of barium perchlorate 1st titration
titrant used for blank, ml 2nd titration
Average
1st titration = Q 99 to 1 01 or
2nd titration
Run 1
Run 2
Run 3
titration _ 2nd titration | ^ 0.2 ml
SULFUR DIOXIDE ANALYSIS
V i - Total volume of solution in which the
° sulfur dioxide sample is contained, ml
V - Volume of sample aliquot, ml
a
V - Volume of barium perchlorate 1st titration
titrant used for sample, ml 2nd titration
Average
V. . - Volume of barium perchlorate 1st titration
titrant used for blank, ml 2nd titration
Average
Run 1
Run 2
Run 3
1st titration
2nd titration
SIGNATURE OF ANALYST
= 0.99 to 1.01 or |1st titration - 2nd titration| ^ 0.2 ml
SIGNATURE OF REVIEWER OR SUPERVISOR
Method 8 analytical data sheet,
11-24
-------
Plant- ;
Si-l-p-
Date
Front Rinse
Back Rinse
Solution:
Volume: Ini
Clean Up By:
City?
Sam. Type:
Rnn No:
Front Filter Front Solu
Back Filter | ~| Back Solu
T,(=\7fai w^rk^d «
^
^
f-ial Final rg
a
Example sample label.
U25 * U'S-
PRINTING OFFICE: 1978 640-O13/4167 Reoion No. 4
NOVEMBER 9
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1 REPORT NO
2
4 TITLE AND SUBTITLE
Field Sampling Manual
7 AUTHOR(S)
9 PERFORMING ORG \NIZATION NAME AND ADDRESS
PEDCo Environmental, Inc.
11499 Chester Road
Cincinnati, Ohio 45246
12. SPONSORING AGENCY NAME AND ADDRESS
Division of Stationary Source Enforcemen
U.S. Environmental Protection Agency
Washington, D.C. 20460
3 RECIPIENT'S ACCESSION NO.
5 REPORT DATE
September 1978
6 PERFORMING ORGANIZATION CODE
8 PERFORMING ORGANIZATION REPORT NO.
P/N 3370-2-K
10 PROGRAM ELE MENT NO.
11 CONTRACT/GRANT NO
68-01-4147, Task
54
13 TYPE OF REPORT AND PERIOD COVERED
Final
^- 14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
DSSE Project Officer: K. Foster
16. ABSTRACT
The field sampling manual was designed to provide field en-
forcement personnel with a source sampling reference manual suitable
for field use. It contains a double-spaced, typed version of the
EPA New Source Performance Standards Test Methods 1 through 8 and
sample data sheets specifically designed for use with the revised
methods to obtain all necessary information.
17.
a DESCRIPTORS
KEY WORDS AND DOCUMENT ANALYSIS
b IDENTIFI
Air Pollution ^^e
Emission Measurements _
_ ,. . New So
Enforcement ance
1S DISTRIBUTION STATEMENT
Unlimited
19 SECURI
Un
20 SECURI
Un
ERS/OPEN ENDED TERMS c COSATI Field/Group
Manual 13B
Sampling
urce Perform- 14D
Standards
TY CLASS (ThisReport/ 21 NO. OF PAGES
classified 204 p.
TY CLASS (Thispage) 22 PRICE
classified
EPA Form 2220-1 (9-73)
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