September 1975
HIGH VOLUME AND GAS BUBBLER
SAMPLER PREPARATION, INSTALLATION,
AND AUDIT PROCEDURES
Region V
Regional Air Quality Assurance Network
prepared by: John Logsdon and Walter Kocal
Centra] Regional Laboratory
1819 W. Pershing Rd.
Chicago, IL 60609
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Tab!e of Contents
Secti on * Topic
1.0 Introduction
2.0 High Volume Equipment Maintenance Schedule
3.0 High Volume Sampler Equipment Description and Service
4.0 High Volume Sampler Calibration Procedures
5.0 High Volume Sampler Field Audit Procedures and Data
Reporting
6.0 Bubbler Sampler Equipment Maintenance Schedule
7.0 Bubbler Sampler Equipment Description and Service
8.0 Bubbler Sampler Audit Procedures
9.0 Station Set-up
10.0 Sampler Audit Data Evaluation Criteria
11.0 Station Evaluation and Inspection
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List of Figures
Section Figure Title
2.2 1 High Volume Sampler Operations Flow Chart
3.2 2 High Volume Shelter Unit
3.3.1 3 High "Volume Motor Assembly
3.4.1. 4 Recording Transducer Unit
3.4.2.1 5 Transducer Calibration System
3.4.2.2 6 Transducer Calibration Data Sheet
3.5.2 7 Step Down Transformer - 16 volt drop
3.5.3 8 Step Down Transformer - 32 volt drop
4.2.2 9 Orifice Calibration Set-up
4.2.2.5 10 Orifice Calibration Data Sheet
4.2.2.12 11 Orifice Calibration Data Plot
4.3.1 12 Sampler in Service Position
4.3.2.6 13 Sampler Calibration Data Sheet
5.3 14 High Volume Sample Audit Data Sheet
6.3 15 Bubbler Operations Flow Chart
7.2 16 5-gas Sampling Rack
7.4 17 Membrane Filter Unit
8.2 18 Bubbler Leak Check Data Sheet
9.5 19 High Volume Sampler Support
9.5 20 High Volume and Bubbler Sampler Support
11.1 21 High Volume Sampler Inspection Sheet
11.1 22 Bubbler Sampler Inspection Sheet
11
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1.0 Introduction
1.1 This manual describes the operations required of Environmental
Protection Agency (EPA) personnel for set-up, calibration, and
maintenance of Regional Air Quality Assurance Network (RAQAN)
particulate and bubbler samplers. Operating and analytical proce-
dures are described in detail in other manuals.1'2}3'l+ It is not
the purpose of this manual to rewrite the manufacturers procedures,
but to reemphasize and clarify certain points. Rather, portions
of the manufacturers "user manuals" are referenced and applied
specifically for RAQAN use.
1.2 Maintenance schedules are outlined and provide expected service,
calibration, and audit intervals. Revisions of this manual will
follow as experience suggests the need for change. Close adherence
to the procedures in the current revision should be maintained.
2.0 High Volume Equipment Maintenance Schedule
2.1 Routine maintenance to be performed by the station operators is
described in other manuals.1'2
2.2 High volume sampler maintenance and audits should be performed as
directed by the schedule in Table I.
This schedule describes audit and maintenance outputs for each site
on a relative timetable. The absolute timetable is left to the
discretion of each District Office. A flow chart of the operations
1s shown in figure 1.
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Step
1
2
3
Time
(months)
0
0
0
5
6
7a
8a
9a
10a
11
6
6
12
12
12
12
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Hiqh Volume Maintenance and Audit Schedule
Operation
Sampler Preparation
Installation
Multi-point Calibration
and Single-point Audit
Two-point Audit
Routine Preventive
Maintenance
Multi-point Calibration
Two-point Audit
Routine Preventive
Maintenance
Special Maintenance
Multi-point Calibration
Orifice Unit Recalibration
aRepeat every 6 months.
Output
Calibration Curve
Audit Report,
Field Inspection Sheet
Calibration Curve
Audit Report
Field Inspection Sheet
Calibration Curve
TABLE I.
la
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High Volume Sampler Operations Flov; Chart
Equipment Purchase,
• Preparation
Sampler
"Calibration
Fail-
Installation
Routine
Operation
Multi-point
Calibration
Evaluate Audit Data
Reject/Accept Data
Figure 1.
Ib
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2.2.1 This schedule requests a number of important outputs for data
evaluation and station maintenance. Samplers prepared and cali-
brated at the laboratory and taken to the field require an audit
after installation to verify the accuracy of the earlier cali-
bration that no damage has occured during transit. On-site cali-
bration and audit is an alternative.
After 6 months of routine operation and pending no field operation
failures during this time, a two point calibration audit should
be performed. If the audit data are acceptable (criteria given
in section 10.), the past 6 months monitoring data are accepted,
routine and special maintenance are performed, and the sampler
is recalibrated.
If the audit data are unacceptable, the air quality monitoring
data will be rejected, corrective action for the sampler taken,
and calibration performed.
2.2.2 Steps 7 through 10 are performed every 6 months. This schedule
allows for good preventive maintenance practices and provides
a continuing record of the sampler's performance.
Maintaining this schedule is essential since it provides a mechanism
for identifying blocks of suspect data and qualifying blocks of
acceptable data.
3.0 High Volume Sampler Equipment Description and Service
3.1 One objective of the RAQAN is to replace all existing samplers with
aluminum General Metals Works* shelters equipped with 2000 M motors,
*Mention of manufacturer's name does not constitute endorsement of the
equipment by the EPA or the Central Regional Laboratory.
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recording transducers, voltage reduction transformers, and program-
mable automatic timers. Only procedures pertaining to these units
will be presented. However, various combinations of these units
may exist,and the specific device procedures will still apply.
The procedures are formatted to illustrate installation of a new
sampler. However, most procedures are applicable to old units
as well.
3.2 High Volume Shelter
3.2.1 Figure 2 shows a high volume shelter unit. Assembly consists
of only attaching the roof to the main unit via the hinges and
removing all packing material. Check for and report any damage
to new units to the CRL.
«
3.2.2 Check all latches for easy operation. It may be necessary to
bend the latches or hinges to get a firm fit.
3.2.3 Inspect the structure for loose screws or components and make
repairs as necessary. Also inspect the shelter for sharp and
hazardous edges. If necessary, file the edges to avoid injury
to personnel.
3.2.4 Using a 1" x 1" or 1" x 2" firring strip, cut a length of the
wood strip to fit from the front of the shelter to the top of
the inside of the open roof. Figure 2. This will avoid undesired
closing of the roof during service of filter insertion.
3.2.5 Using a stencil, paint the words:
U.S. EPA
REGION V
on the outside of the roof and on the side panel of each shelter.
The motor number from the metal plate attached to the side of
the motor should be recorded inside the shelter roof. This number
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Figure 2.
High Volume Shelter Unit
Js
Voltage reduction
transformer
Programmable
timer ~~
US EPA
R E G I 0 N V
. Roof latch
Sampler motor
Recording
transducer
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must be changed to reflect any changes in the motor used, i.e.,
replacing a burned out unit.
3.3 High Volume Sampler Motor Assembly
3.3.1 Figure 3 shows a motor assembly and a parts schematic diagram.
This diagram also shows a filter adapter.
3.3.2 Remove the motor assembly from the shelter by unplugging the
electrical cable, disconnecting the pressure hose from the side
of the motor and carefully lifting the motor through the top
of the shelter.
3.3.3 Inspect the filter adapter for damage. Be sure that the face-
plate is not bent and fits squarely on the adapter. Also, check
the rubber gasket for a tight seal to the faceplate and no dried
or cracked sections.
Every 18 to 24 months it may be necessary to replace this gasket.
The life of each gasket is a function of the sampler location
and must be checked at least every 18 months. Replace any
gasket that does not seal properly or is damaged. This will
be noticed by the station operator or the CRL since the filters
will show rough borders for the particulate matter.
3.3.3.1 Remove the faceplate and using a razorblade or putty knife,
remove the old gasket. Scrape the faceplate clean.
Using rubber cement, attach the new gasket, place the faceplate
on the adapter, tighten the wingnut clamps carefully, and wipe
any excess cement off the unit. This cement sets up quickly.
Inspect the unit to verify proper installation.
3.3.4 Inspect the retaining ring fit to be sure it is not cross threaded.
Using a strapwrench (if available), tighten the ring until the
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units are sealed together. Do not overtighten the unit.
3.3.4.1 It may be necessary to change the gasket under the retaining
ring if the gasket is cracked and dried. Simply loosen the
ring, replace the gasket, and retighten the retaining ring.
3.3.5 Motor Brush Replacement
3.3.5.1 Every 6 months the motor brushes should be replaced to avoid
commutator damage and motor burnout. New motors require burn
in as described in section 3.3.5.8. Refer to the GMW 2000 H
manual for details.5
3.3.5.2 Remove the filter adapter.
3.3.5.3 Remove the 4 screws on the adapter mounting plate. Remove
gasket #1, motor, gasket #2, and the ring.
Carefully push or pull the three wire cord until a sufficient
working length is through the housing.
3.3.5.4 Remove the brushes noting their original position. Inspect
the commutator for excessive wear such as grooves, chipping,
or burned spots. The armature may also have to be replaced.
If the condition of the motor is acceptable, install new brushes,
3.3.5.5 Inspect gaskets #1 and #2 and the wiring. Replace or repair
the unit as necessary.
3.3.5.6 Replace the motor unit being careful not to bind the cord inside
the assembled unit. Replace the adapter mounting plate and
the 4 screws.
3.3.5.7 Attach the filter adapter and install a clean filter or the
orifice calibration unit and the 18 hole plate.
3.3.5.8 With a variac, apply 50 volts to the motor. Carefully look
Into the motor exit orifice for excessive sparking. If noted,
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the brushes or the armature may be defective. Repair the motor
as necessary. Run the motor for 15 minutes at 50 volts to
"burn-in" the new brushes. Advance the voltage to 100 volts
and again inspect the motor for excessive sparking. Proceed
if no problem is apparent. Otherwise, make repairs as necessary
by going over the procedures once again and very carefully
checking the commutator. Run the motor an additional 15 minutes
at 100 volts.
3.4 Recording Pressure Transducer
3.4.1 Figure 4 shows a recording transducer unit. Refer to the figure
and the manufacturer's manual for the following procedures.6
3.4.2 Every pressure transducer should be calibrated when received
or when service has been done to the unit.
3.4.2.1 Set up a calibration system as shown in Figure 5. Restrict
the open side of. the first "tee" until the system may be
adjusted easily for pressures from 0-10 inches of water.
3.4.2.2 Using a chart calibrated from 0-10 inches of water (supplied
with each new transducer), adjust the transducer zero control
for a zero reading. Apply 8-10 inches of water pressure
(measured by the water manometer) and determine the reading
on the transducer chart. If the chart reading is not within
±1 inch of water pressure, adjust the recorder span control
in the back of the unit. Readjust the zero and span controls
until the span reading is within ±1 inch of the true pressure
and the zero is within ±0.5 inches of zero. Check at least
2 additional points and record the results in the data sheet
1n Figure 6.
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8
- Pen
Time Set
Point
Zero Set
Front View
Zero Set
Bellows
T
Chart Drive Motor
(
Pressure Tap
Figure 4. Recording Transducer
'Back View
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Figure 5. Transducer Calibration System
Restricted Tee _f
H
Transducer Unit
Water Manometer
To Air Supply ( 20 in. HO)
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Figure 6.
Tranducer Serial No.
Operator
Date
Point
Zero
Span
1
2
3
4
Actual Pressure
in H20
Chart Pressure
in H20
j
Error
in H20
6c
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3.4.2.3 Adjust the recorder span control by removing the back of the
•] transducer, carefully loosening the adjustment screw, moving
the slip arm to a new position, tightening the screw, and check-
ing the zero and span recorder values. Continue this adjust-
.* " ment operation until the recorder span reading is within ±1
inch of the true reading.
This is a delicate operation and may require some practice
before the operation can be done quickly. Replace the back
of the transducer being careful to seat the gasket properly.
3.4.3 The chart motor may fail occasionally. The CRL maintains some
replacement units and upon request will send them out for
replacement by District Office personnel.
3.4.4 The pen is the most frequent part to fail. During each site
visit, check the pen for dried ink and carefully clean it with
acetone, alcohol, or hot water. Also, check the pen arm to be
sure it applies sufficient pressure on the pen to the chart.
Repair or replace the pen arm as necessary. If the pen does
not ink properly, vary the pressure by sliding the pen point
on the pen arm toward or away from the chart. It is not necessary
to bend the pen arm.
»
3.5 Voltage Reduction Transformer
3.5.1 Each sampler is equipped with a voltage reduction transformer.
This transformer should be wired to provide sufficient drop to
make the air flow rate through a clean filter be about 50 cubic
feet per minute (1.35 nr/min).
3.5.1.1 Determine the correct voltage by using a variac to supply the
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the motor. Set the variac for an air flow rate of 50 cfm
o
(1.35 m /min). Measure the voltage on the variac. Wire the
transformer for the voltage drop that will yield a voltage
closest to that measured from the variac.
3.5.2 16 volt drop. Figure 7 shows the wiring diagram for a 16 volt
drop. The windings X1X2 and X3X4 are wired in parallel. Be
careful to not leave any wires exposed that could cause shock
injury.
3.5.3 32 volt drop. Figure 8 shows the wiring diagram for a 32 volt
drop. Windings X1X2 and X2X3 are in series. The resultant
voltage will be about 81 volts. Once again, pay attention to
lead dress.
3.6 Each new sampler is equipped with a programmable automatic timer.
The operation of the timer is described on the weather door and
in the field operations manual.1
3.6.1 Any service for this timer should be referred to the CRL at this
time. Additional information will be distributed as it becomes
available.
3.6.2 It may be necessary to add an additional outlet to be able to
carry enough current to operate both the high volume sampler
and gas bubbler. General Metals Works is providing an accessory
outlet that can be operated by the timer and provide switched
contacts to handle up to 15 amps continuous. Consult the CRL
for the availability and installation of these units.
3.6.3 Each elapsed time indicator should be checked for accuracy before
installation in the field. Record the elapsed time indicator
reading in a log book or on the motor calibration data sheet
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Figure 7.
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in figure 13. Record the timer serial number, start the timer,
and record the time of day from an accurate clock. Consult the
local telephone company or a bank time system if necessary to
verify the clock accuracy.
After about 24 hours, record the time of day and elapsed time
indicator reading. Determine the difference of the true (clock
time) and the indicated time. The error must be less than ±4
minutes to satisfy the Reference Method specifications. If
the error is too great, contact the CRL for a new elapsed time
indicator.
4.0 High Volume Orifice Calibration Procedures
4.1 High volume sampler motors are calibrated with an orifice calibra-
tion unit. The orifice units will be calibrated at the CRL on
a yearly basis or at the District Office's request.
4.2 Orifice Calibration
4.2.1 The following equipment is necessary:
4.2.1.1 Positive displacement flowmeter (Rootsmeter)
4.2.1.2 -Water manometer (0-16 inches of water)
4.2.1.3 Mercury manometer (0-120 mm Hg)
4.2.1.4 AC voltmeter (0-150 volt)
4.2.1.5 Stopwatch (0.01 sec accuracy)
4.2.1.6 Connecting tubing
4.2.1.7 Logarithmetic Graph Paper (2x3 cycle)
4.2.1.8 Variac (variable voltage transformer)
4.2.2 Set up the calibration system as shown in figure 9.
4.2.2.1 Attach the orifice calibration unit to the intake of the
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Orifice
Calibration
Unit
H To Water Manometer
1
tl
X"
«»OA
!>*...* *
«^"*"^
1
•BMMMMK!
P To Mercury Manometer
Roots Meter
Hi-Vol Motor
To 110 vac Source
Figure 9. Orifice Calibration Set-up
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rootsmeter.
4.2,2.2 Connect one end of the water manometer to the differential
pressure tap of the orifice calibration unit; the other end
is open to the atmosphere.
4.2.2.3 Connect one end of the mercury manometer to the inlet pressure
tap of the rootsmeter; the other end is open to the atmosphere,
4.2.2.4 Attach a high volume sampler motor to the exhaust of the roots-
meter. Attach the variac to the motor power cord and plug
the variac into the wall outlet.
4.2.2.5 Record the ambient temperature and pressure on the data sheet
in figure 10.
4.2.2.6 Place the load plates , one at a time, between the orifice
and rootsmeter. Turn on the high volume sampler motor and
allow it to warm up for 10 minutes. Also adjust the variac
to obtain 110 VAC to the motor. Maintain this voltage through-
out the entire calibration.
4.2.2.7 Record the v/ater manometer and mercury manometer readings on
the data sheet.
4.2.2o8 Record the time, in minutes, required to pass the known volume
of air.
4.2.2.9 Repeat 4.2.2.6, 7, and 8 until data for all 5 load plates are
obtained.
4.2.2.10 Calculate the airflow rate measured by the rootsmeter for each
load plate.
.Nm Pa t
where Qm = True air flow rate at ambient conditions (rrr/min)
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Date: 9/11/75
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a = Ambient Pressure (mm Hg)
a
Pm = Rootsmeter inlet differential pressure (mm Hg)
o
V = Volume of air measured (m )
T = Time to pass Vm (min)
4.2.2.11 Correct each flow rate to reference conditions of 760 mm Hg
and 298°K.
•3
where Q = Air flow rate at reference conditions (m /min)
Tm = Ambient temperature during calibration (°K)
Pm = Ambient pressure during calibration (mm Hg)
Qm = True air flow rate at ambient conditions (nr/rnin)
4.2.2.12 Plot the water manometer reading (AH) vs. reference air flow
rate (Q ) on 2x3 cycle logarithmic graph paper and determine
the best fit line. An example of the data is shown in figure 11.
4.2.2.13 Calculate the deviation of each point from the best line and
record the result on the data sheet.
Percent deviation = -~ - - x 100
%
where Q0 = measured point
Qc = corresponding point from line
If the devjition is ±3% or greater, for any one or more points ,
the compl ete^caJLihrati on.-mustJ3e~perfDrmed»aga-iru_
4.3 High Volume Motor and Transducer Calibration
4.3.1 Place the sampler motor in the service position. Figure 12.
If the calibration is geing done in the laboratory, an empty
.shelter or a wooden frame may be used to mount the motor in.
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Figure 12. Sampler in Service Position
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h
•e
Orifice S/N
Transducer S/N
Figure 13.
HIGH VOLUME SAMPLER CALIBRATION DATA SHEET
Hi-Vol Motor S/N
Date
Sampler Location
Calibrator
NASN Site No.
Office
Ambient Temperature
Pressure
Voltage
Clean Filter Reading
Calibration Equation Slope:
Intercept:
Load
Plate
No.
18
13
10
7
5
Manometer
Reading
in. H20
Transducer
Chart
Readirg
Air
Flowrate
M /min
Error
%
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4.3.2.0 Calibration Procedure
4.3.2.1 Replace the filter adapter with the orifice calibration unit
using the 18 hole load plate.
4.3.2.2 Connect one side of the water manometer to the orifice calibra-
tion unit.
4.3.2.3 Install a clean recorder chart.
4.3.2.4 While lightly tapping the recorder, turn the zero adjust screw
in the lower right hand corner until the pen reads zero.
4.3.2.5 Connect the motor directly to the variac, bypassing the trans-
former.
4.3.2.6 Record the ambient temperature and pressure on the data sheet
(figure 13).
4.3.2.7 While watching the water manometer, adjust the variac until
the differential pressure indicates an air flow rate of 1.7 nr/min
Record the voltage and maintain the same voltage for the entire
calibration.
4.3.2.8 Let the motor run for 10 minutes, then read and record the
transducer chart and differential pressure.
4.3.2.9 Repeat steps 4.3.3.4 through 4.3.3.8 for each of the 5 load
plates.
4.3.3 Data Calculations
4.3.3.1 For each load plate, determine the air flow rate corresponding
to the orifice differential pressure (DH) from the reference
orifice calibration curve.
4.3.3.2 Plot the reference flow rate vs. transducer reading on linear
graph paper. Determine the line of best fit by eye or least
squares. This plot is already at reference conditions and
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does not need further correction. See Appendix A.
4.3.3.3 Determine the deviation of the measured points from the best
fit line.
QO - QC
percent deviation = —Q x 100
where Q0 = Measured point
Qc = Calculated point from best fit line
If the deviation is ±5 percent or more for one or more points,
check the calibration system and recalibrate the point in
question. If it still is out of control, recalibrate the motor
using all 5 load plates.
4.3.3.4 Replace the filter adapter and voltage reduction transformer.
Attach a clean filter and turn on the motor. The flow reading
should be between 1.13 and 1.7 riP/min. The optimum value is
1.5 nrVmin. Record this value on the motor calibration data
sheet.
4.3.3.5 Submit copies of both the calibration data sheet and data plot
to the CRL.
5.0 High Volume Sampler Field Audit Procedures and Data Reporting
5.1 Each high volume sampler must be audited to verify its calibration
in the field and laboratory and proper operation. The air flow
rate is audited using an orifice calibration unit, other than the
one used to calibrate the motor. At best, the audit should be
performed by someone other than the person who calibrated the unit.
5.2 Every 6 months and before any field motor replacement or recali-
bration, the calibration must be audited. This allows each set
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of data to be verified by knowing the initial and final sampler
accuracy over the total number of sample periods. This audit is
one of the most important factors for the operation of the RAQAN.
5.3 Using a calibrated orifice calibration unit, place the motor into
the service position and attach the orifice with the 18 hole plate.
Turn on the sampler and allow it to run for 10 minutes. Read the
differential manometer pressure and transducer chart and record
the data in figure 14.
Repeat this operation for the 13 hole plate.
5.4 Determine the reference flow rates from both the orifice calibra-
tion curve and the motor calibration curve. Compare the flow rates
and calculate the percent error. If the flow rate error is greater
than ±6 percent, check the transducers tubing, amd motor for damage.
Make any necessary repairs and recalibrate the system. If the result
are acceptable, continue with routine scheduled maintenance and
sampler recalibration.
5.5 Report the calibration audit data to the CRL on the report form
(figure 14). Any action taken at the site, in the event of an
audit failure should be documented.
6.0 Bubbler Equipment Maintenance Schedule
6.1 Routine maintenance for the gas bubbler sampler should be performed
by the station operator and is described in another manual.2
6.2 A relative maintenance and audit schedule is shown in Table II.
This schedule lists the operations and audits to be performed and
should be scheduled to coincide with the high volume sampler mainte
nance and audit visits.
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Figure 14.
Calibration Audit Data Sheet
Site Location
Sampler Motor No.
Operator
Auditor
Date
Barometric Pressure
Ambient Temperature
Orifice Serial No.
Plate
No.
18
13
Transducer
Chart
Orifice
Pressure
Flow rate1
From Orifice
Flow rate1
From Sanioler
Error2
HI
K
rates should always be at reference conditions.
2Error = Orifice Flow Rate - Sampler Flow Rate ,n_
Orifice Flow Rate x IUU
14a
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6.3 The Table lists a number of outputs requested for an operation
such as the leak test audit report sheet. These data provide a
continuous record of the performance of the sampler and are used
to validate data and identify problems. Each operation is described
in detail in section 7, 8, and 9.
An operations flow chart is given in figure 15.
7.0 Bubbler Sampler Equipment
7.1 The procedures for the sampler set-up and maintenance assume a
unit is being prepared from a new Research Appliance Company (RAC)
5-gas Sampler in the All-Weather Shelter.7 If a unit is being
serviced that has already been assembled, go to the step covering
the operation being performed and proceed. These procedures will
be applicable to most types of ges bubbler equipment and are not
unique to RAC samplers.
7.2 The All-Weather Shelter contains a vacuum pump, vacuum gauge, 5-gas
sampling rack, and heater. Figure 16. If the unit is new, extra
supplies will be shipped in the 5-gas sampling rack. Save these
extra parts. Some can be used for servicing the sampler.
7.3 New samplers are equipped for use with 5 sample tubes. The RAQAN
only measures SC^ and NC^. Therefore, remove the 3 bubbler trains
farthest from the manifold inlet from the rack.
Cap the unused glass manifold ports with polypropylene caps (these
cops are used as closures for the sample tubes sent to the station
operator arid are available from the CRL). It may be necessary
to heat the caps to get a good force-fit seal. Small yellow plastic
caps are available from the CRL to close the unused vacuum manifold
ports. As an alternative, rubber septums or 1/8 inch gas chromatograph
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Page:
TABLE II.
Step
1
2
3
4
5
6
7
8
9
10
11
Time
(months)
0
0
0
6
6
6
12
12
12
12
12
Operation
Sampler Preparation
Leak Check
Installation
System Leak Check
Change Membrane Filters
and Septums
System Leak Check
System Leak Check
Change Membrane Filters
and Septums
Perform Sampler Clean-up
Check Pump System
System Leak Check
Output,
Audit Sheet
Audit Sheet
Field Inspection Sheet
Audit Sheet
Audit Sheet
Field Inspection Sheet
Repeat steps 4 through 11 every year.
14b
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Bubbler Sampler Operations Flow Charl
j Equipment Purchase
System Preparation
System Audits
-Fail-
Pass
Installation
'J
Routine Operation
Fail-^—
Major Repair
Data Evaluation
Routine Maintenance
Pass
Rejection
Routine Operation
Data Evaluation
Rejection
Figure 15.
15a
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Manifold Rack
D
Z)
33
^
i
C
a
c
c
Metal Manifold
Glass Manifold
Teflon
Tubing
Sample Tube
Vacuum Pump
Membrane Filter
Mist Trap
Figure 16. 5-Gas Sampling Rack and Manifold
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• . Revision 1
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column caps may be used.
These caps should be checked at installation and each visit there-
after for visual signs of leaks or cracks and replaced if necessary.
7.4 Remove the remaining two sample trains. Note their configuration.
Referring to figure 17, press the membrane filter holder together
tightly and seal the halves together using acetone or methylene
chloride. Every filter unit should be sealed prior to installation
to avoid air leaks in the system. Be sure the tygon tubing attach-
ing the filter to the glass tubing is also sealed to the filter
housing.
Again, it may be necessary to seal the tubing and filter unit
together with acetone.
7.4.1 When replacing the filters during the Semiannual maintenance
visits, prepare the assembly as shown in figure 17 in advance.
This assembly may be prepared from V I.D. tynon, filter unit;
straight and 90° bent pieces of glass and rubber septum. The
glass pieces should be reused and the old filter and tubing
discarded. The filters should be replaced every 6 months.
7.4.2 Check the tygon tubing for a tight fit at the inlet and outlet
ports of the mist trap. Also, be sure the tubing to the absorber
tube fits tightly. Replace any tubing that is defective or does
not fit tightly on the absorbers or mist traps.
7.4.3 Replace the bubbler trains and attach the teflon inlet tubing
directly to the glass manifold. Also attach the rubber tubing
from the vacuum pump to the metal vacuum manifold.
7.5 Check the vacuum pump and gauge by turning on the pump and pinching
the rubber vacuum tubing tightly. The gauge should read 20 or
-------
90U Glass Elbow
Membrane Filter
Assembly
Rubber Septum
^^^ x"
Tygon Tubing
Tygon Tubing
Straight Glass Tubing
Tygon Tubing
Figure 17. Membrane Filter Unit
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Revision 1 17
Page: ''
greater. If not, the pump or gauge needs repair or replacement.
7.5.1 The gauge may be replaced by simply unscrewing it from the "Tee."
When installing the new gauge, use Teflon tape to insure a good
seal and avoid damaging the pipe threads.
7.5.2 The vacuum pumps may fail. Usually the pump diaphram and inter-
nal gaskets fail before the motor. When a pump fails, it should
be replaced with another unit in the field and repaired at the
laboratory. Pump rebuild kits will be available upon request
from the CRL or the pump may be sent to the CRL for repairs.
7.6 Heater units are provided in the bottom of the bubbler rack section
of the All-Weather Sampler. This 35 watt heater should be connected
to an always-on power source from late Fall to Spring to avoid
sample loss due to freezing. The heater will be warm to the touch
when operating properly. The box temperature should be between
10-34°C dependent upon the ambient temperature.
If a unit fails, replace the heater. The CRL will supply extra
heaters upon request.
7.7 Replace the sampling train; be sure all the tubing is properly
attached. Plug the pump into a timer switched outlet and the
heater into an always-on outlet if the weather is cold.
The sampler should be operated only on sampling days with needles
and absorbing solutions in place,
8.0 Bubbler Audit Procedures
8.1 Air leaks are a major source of error for gas sampling systems.
The bubbler trains can leak air at the rubber septum, membrane
filter, and all tubing connections. Any air leak will cause the
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Date: 9/11/75
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Page: '8
data to be biased lev/. Therefore, after preparation, 6 months
of operation or service, the system should be checked for leaks.
8.2 Referring again to figure 16, install the dummy absorbing tubes.
Attach the water manometer from an orifice calibration unit to
the inlet of the glass manifold. Attach a hypodermic needle to
one of the open vacuum manifold ports. Close the other with a
plastic cap, rubber septum, or another needle. Turn on the vacuum
pump. Push the needle through the rubber septum and carefully
watch the vacuum develop on the water manometer. When 10-15 inches
of water differential pressure develops, pull the needle from the
septum. Both bubbler trains and glass manifold are now sealed.
Record the differential pressure in figure 18.
Wait one (1) minute and record the final differential pressure
in figure 18. Determine the difference. If the differential
pressure dropped more than 1 inch of water, a leak exists. Check
all joints and seals and repair the leak. Repeat the test until
the change in differential pressure is 1 inch or less. Report
the data to the CRL.
This is a requested output (Table II) and must be performed regularly.
9.0 RAQAN Station Set-up
9.1 When locating air monitors, adhere to siting guidelines OAQPS
No. 1.2-012 Table I as closely as practicable.
9.2 The High Volume Air Sampler and Gas Bubbler must be mounted securely
to a sturdy base,and the base must be weighed down with building
blocks to prevent being blown over by high winds.
9.3 Material List for High Volume Sampler Installation
-------
Figure 18.
Bubble Systeni Leak Check
Sampler Location
Sampler Serial No.
Auditor Date
New Unit j j , before service LJ
after service Q
Test 1
Set Pressure:
Initial Differential Pressure in. H20
Wait 1 minute:
Final Differential Pressure ia H20
Difference in. H20
If Difference is 1 in. HpO or less, unit passes test. If greater
than 1 in. h^O, repair leaks, perform another test, and repeat process
until acceptable criteria are met.
Test 2
Set Pressure:
Initial Differential Pressure in. H20
Wait 1 minute:
Final Differential Pressure '_ in. hLO
Difference in. O
I8a
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9.3.1 4 - 2" x 4" x 6' lumber
9.3.2 2 - 1" x 6" x 18" lumber
9.3.3 2 - building blocks
9.3,4 8 - V x 3" lag screws
9.3.5 4 - V -x 2V round-head stove bolts and nuts
9.3.6 16 - 5/16" I,D., 3/4" O.D. flat washers
9,3.7 8 nails
9..3.8 V1 thick, 14" x 14" plywood
9.4 Paint or treat all of the lumber with 2 coats of paint or wood
preservative. Let it dry 24 hours between coats and before instal-
lation,
9.5 Sampler station set-up. Figure 19 shows a top view of the support
necessary for a high volume shelter. The following procedures
are for placement of a single hi-vol only. However, by using the
parts list in section 9.7, and making the appropriate changes in
the procedure, a support for both a hi-vol and a bubbler can be
constructed as in figure 20.
9.5.1 Set the Hi-Vol Sampler on a h" thick 14" square section of ply-
wood or similar material. This will provide the clearance between
the building roof and the sharp corners of the shelter legs.
Lay a 2 x 4 on the roof with the wide side against the shelter
legs. Center the 2 x 4 and drill 5/16" holes through the 2 x 4
and the shelter legs. Bolt the shelter to the 2x4 with V x
2V1 stove bolts, nuts, and washers.
9.5.2 Do the same with the second 2x4.
9.5.3 Remove the V thick 14" square section of plywood.
9.5.4 Nail the 1" x 6" x 18" boards across the top of the 2 x 4's,
-------
/ -4 x 3" lag screws
%- - - \J ' - ' ' '• -*"
•» *»
fi !!
f
k x 2%" stove bolts,
washers and nuts
t
«
t>
%
*
^_ ,'7tf _
f J)
|r n
Hi- VOL
L. _J
it
%
«
•-
*
»
i;
^ >
_L 6"
BLOCK
SUPPORTS
i"x6"xl8"
1
€
s
C?
^ 6
. 1.
k
'
>
*< it
x 3" lag bolts
Figure 19. High Volume Sampler Support
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Date: 9/11/75
Revision 1
Page: 20
six inches from the end of the 2 x 4's. This will support the
building blocks.
9.5.5 Fasten the 3rd 2 x 4 against the ends of the pair of 2 x 4's
supporting the shelter. Use 4 - V x 3" lag screws.
9.5.6 Fasten the 4th 2x4 against the opposite ends of the 2 x 4's
supporting the shelter.
9.6 For the power line use a weatherproof three conductor #16 gauge
cable if only one Hi-Vol sampler is being installed.
9.6.1 If a Hi-Vol Sampler and a Gas Bubbler are to be installed, use
#14 gauge 3 conductor cables. Use a weatherproof outlet box
and three prong receptacle.
9.7 Material List For Hi-Volume Sampler and Gas Bubbler Installation
9.7.1 2 - 2" x 4" x 6" lumber
9.7.2 2 - 2" x 4" x 8" lumber
9.7.3 2 - 1" x 6" x 18" lumber
9.7.4 8 - V x 3" lag screws
9.7.5 4 - V x IV lag screws
9.7.6 4 - V x 2h" stove bolts and nuts
9.7.7 16 - 5/6" I.D., 3/4" O.D. flat washers
9.7.8 2 - building blocks
9.7.9 8 - nails
9.7.9.1 V x 14" x 14" plywood
9.7.9.2 2 - V x 5/8" round-head stove bolts
9.7.9.4 1 - V x 10' thinwall conduit
9.7.9.5 12' - 5/16" teflon tubing
9.7.9.6 1 - polypropylene funnel - V O.D. stem
-------
x 3" lag screws
x 2V stove bolts,
washers and nuts
x IV lag screws
HI-VOL
15'
GflS '
BUBBLES
3'
J
N
BLOCK
SUPPORT
I"x6"x|8" 8
,11
t ' J
^ x 3" lag screws
Figure 20. High Volume and Bubbler Sampler Support
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Date: 9/11/75
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10.0 Sampler Audit Data Evaluation Criteria
10.1 Sampler calibration and system audits are described within the
test, i.e., Hi-vol flow rate audit error limit is ±6 percent.
However, to assess the overall quality of the monitoring data,
the audit data must be summarized and reported to cause acceptance
or rejection of the monitoring data.
At the time of this writing, no sufficient amount of field audit
data are available to set limits and specific evaluation criteria.
However, as soon as 6 months of auditing data are available, this
section will be revised to describe specific evaluation techniques
for determining the quality of the air monitoring data.
11.0 During each site visit, as well as performing routine maintenance,
a record should be made of the action taken and any deficiencies
that must be corrected during the next visit.
11.1 Figures 21 and 22 show suggested inspection record sheets. (Pre-
pared by Peter Gill en of MWDO) The sheets should be filled out
for each site after each visit. A copy should be submitted to
the CRL.
-------
Hi-Vol Serial No.
RASN Site No.
Site Location
Street Address
City & State
Figure 21.
U.S. EPA
Equipment Evaluation
Hi-Volume Air Sampler
DATES
Inspection
Last Calibration _
Last Brush Change
Item
Deficiency
Action taken
Action Required at
next inspection/visi
Shelter
Shelter base
Weights
Cover Latch
Motor housing
Rotor
Brushes
Filter cone
Screen
Pins
Wing nuts
Hold-down plate
Filter gasket
Rubber gasket
Transducer (S/N
Tubing
Voltage reducer
Timer (S/N
Electrical cords
Electrical plugs
Comments on changes affecting height of site, obstructions or factors affecting the site
and other comments.
-------
Bubbler Serial No.
RAQAN Site No.
Site Location
Street Address
City & State
Figure 22.
U.S. EPA
Equipment Evaluation
Gas Bubbler
Date
Inspection
Item
Deficiency
Action taken
Action Required
next inspection/vi
Shelter Box
Shelter Base
Weights
Pump
Vacuum gage
Vacuum tubing
Electrical cord
Electrical plugs
Timer
Probe
Tubing
Funnel
Heater
Heater cord
Bubbler insulation
Bubbler rack
Glass manifold
Brass manifold
Manifold plugs
T-jbing
Tubing connections
Demisters
Demister sponge or wool
Demister connections
Membrane filters
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Date: 9/11/75
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References
^'Regional Air Quality Assurance Network - Particulate Sampling Procedures
(High Volume Method)," EPA, Central Regional Laboratory, August, 1975.
2"Regional Air Quality Assurance Network - Sulfur Dioxide and Nitrogen
Dioxide Sampling Procedures - Twenty-four Hour Bubbler Method," EPA,
Central Regional Laboratory, August, 1975.
3"Region V Air Quality Assurance Program - The Determination of Suspended
Particulates - High Volume Method - Laboratory Operations Manual," EPA,
Central Regional Laboratory, July, 1975.
'•"Region V Air Quality Assurance Program - The Determination of Sulfur
Dioxide and Nitrogen Dioxide by the Gas Bubbler Method - Laboratory
Operations Manual," EPA, Central Regional Laboratory, July, 1975.
5"0perators Manual - Model GMWL 2000 and Model GMWL 2000H," General Metals
Works, Cleveland, Ohio.
6"0perating Manual for Dickson Recording Instruments," The Dickson Company,
Addison, IL, 1973.
7"0perating Instructions for 5-Gas Collector Sampler, Catalog No. 2333A,"
Research Appliance Company, Allison Park, PA, April, 1972.
22
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Appendix A
.11
JL
_ TEMPERATURE AND PRESSURE CORRECTION SCHEME
The type of temperature and pressure corrections for high volume air
sampler calibrations and flow rate measurement(s) have been questioned
for a considerable length of time. In February, 1975, Dr. Randy Korda
of the Wisconsin Department of Natural Resources and I discussed the
topic at length and agreed upon a correction scheme. The equations are
as follows:
1. Orifice calibration with a positive displacement flow meter (Roots Meter)
Va . lEi^AEl Vm
Va = Air volume at atmospheric conditions T-j and P-, (M^)
P] = Barometric pressure (mrnHg)
AP = Pressure drop at inlet of roots meter (mmHg)
Vm = Uncorrected volume measured by roots meter (M^)
Ql = Va/t
Q-j = Air flow rate at atmospheric conditions corresponding to a
differential orifice pressure, AH, (M^/min)
t = Time to pass air volume Va
QR = Air flow rate at reference conditions TR and PR (M^/min)
TI = Ambient temperature at time of orifice calibration (°K)
P! = Ambient pressure at time of orifice calibration (mmHg)
TR = 298°K
PR c 760 mmHg
-------
The orifice calibration curve is constructed by plotting AH vs. QR on
log-log graph paper. This curve is the same as if the orifice had
been calibrated at reference conditions.
*
2. Sampler Calibration with a Calibrated Orifice Unit.
Orifice differential pressures (AH) and flow indicator device readings'1^
{recording transducer) are recorded for each of 5 load plates. The
flow rate at reference conditions is determined from the AH vs. QR curve
and is plotted on linear, graph paper vs. indicator readings (Qp< vs. I).
This plot is the flow rate at reference condi 'cions and is not_ dependent
upon the conditions when the sampler was calibrated.
3. Air Volume Sampled Determination.
The reference flow rate, QR, from I is corrected to the conditions
during sample collection.
0.2 = Air flow rate at field conditions T2 and ?2 (
T£ = Field temperature during sample collection (°K)
?2 = Field pressure during sample collection (mmHg)
Note that this correction yields the flow rate, Q2, that would be observed
directly from the motor calibration curve, QR vs. I, if the motor calibra-
tion had been performed and reported at field conditions.
The air volume sampled at field conditions is:
-------
V2 c Q2 x t
\2 ~ Air volume sampled at field conditions T£ and P£
t = Sampling time (min.)
The volume is corrected to reference conditions using the gas law equation:
This volume is used to calculate the particulate concentration.
4. The air flow rate and volume correction scheme described here has been
verified experimentally at the Central Regional Laboratory and found to
yeild errors of 2% or less from the actual values determined with positive
displacement flow meters.
An orifice was calibrated at 26°C and at 53°C and the AH vs. QR curves
drawn to reference conditions as described in Section 1. The differences
between the two calibrations are shown below:
Load Plate No. AH QR (26° Calibration) QR(53° Calibration) % Error
18
13
10
7
11.6
9.68
7.18
4.76
1.65
1.49
1.31
1.07
1.64
1.50
1.32
1.06
-0.6
0.7
0.7
-0.9
If the correction was not applied, the errors would be from 4 to 5 percent.
To verify the sampler corrections in sections 2 and 3, a high volume sampler
was calibrated at 26°C and the flow rate vs. flow indicator reading (I) curve
drawn to reference conditions as described in Section 2. Air was then sampled
at 53°C and the flow rate measured by I and a positive displacement flow
-------
meter. The flow rates were then corrected to reference conditions
and the air volume sampled determined,
The volumes found from the flow indicator reading and the roots meter
were compared.
I(cmH20)
16.7
14.1
11.0
7.1
QR(M3/min)
1.64
1.50
1.32
1.06
VR^CALC M3)
94.6
85.4
75.1 '
60.8
VR2(Roots Meter M3)
96.0
85.9
76.0
61.4
% Error
-1.5
-0.6
-1.2
-1.0
^ Air volume sampled at reference conditions for 60 minutes.
p
Air volume measured by Roots Meter and corrected to reference
conditions for 60 minutes.
Once again, had no corrections been applied, the error would have been
3 to 5 percent for this data.
Therefore, the procedures described here and by Dr. Korda minimize the
errors in air volume measurement to less than 2 percent. The corrections
are simple to employ and improve the quality of the data.
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