EPA-670/4-75-001
February 1975
PERFORMANCE OF THE ISCO MODEL 1391
WATER AND WASTEWATER SAMPLER
By
Richard P. Lauch
Methods Development and Quality Assurance Research Laboratory
Program Element No. 1HA327
NATIONAL ENVIRONMENTAL RESEARCH CENTER
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI. OHIO 45268
-------
REVIEW NOTICE
The National Environmental Research Center Cincinnati
has reviewed this report and approved its publication.
Mention of trade names or commercial products does not
constitute endorsement or recommendation for use.
11
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FOREWORD
Man and his environment must be protected from the adverse effects
of pesticides, radiation, noise and other forms of pollution, and
the unwise management of solid waste. Efforts to protect the
environment require a focus that recognizes the interplay between
the components of our physical environment--air, water, and land.
The National Environmental Research Centers provide this multi-
disciplinary focus through programs engaged in
studies on the effects of environmental
contaminants on man and the biosphere, and
a search for ways to prevent contamination
and to recycle valuable resources.
This report is part of a continued effort by the Instrumentation
Development Branch, Methods Development and Quality Assurance
Research Laboratory, NERC-Cincinnati, to evaluate instruments and
provide information to both users and suppliers. Our efforts are
also intended to result in upgraded instrumentation and the
ability to choose the most suitable instrument for a particular
application.
A. W. Breidenbach, Ph.D.
Director
National Environmental
Research Center, Cincinnati
111
-------
ABSTRACT
Performance of the ISCO model 1391 water sampler was tested.
Tests were run at 2, 19, and 35C to check accuracy and precision
of the timer, flowmeter, and sample volumes. The multiplexer
function of delivering multiple aliquots per bottle was tested.
Performance checks were made on both converter and battery power,
and battery endurance was determined. Discrete sample temperatures
were recorded versus time under iced conditions. Manufacturer's
claims were mostly confirmed, but improvement is warranted for
some sampler components.
IV
-------
CONTENTS
Page
Abstract iv
List of Figures vi
List of Tables vi
Sections
I Conclusions 1
II Recommendations 2
III Description of Sampler 3
IV Method of Testing and Equipment Used 5
V Results of Performance Tests
Timed Runs 8
Flowmeter 9
Battery Operation and Endurance 11
Temperature Preservation 11
VI Problems
Spurious Cycles 17
Pump Reversal 17
Suspended Solids 17
VII Discussion 20
VIII Appendix 21
-------
LIST OF FIGURES
No.
1 Schematic Diagram of Flowmeter/Sampler Tests
Within the Environmental Chamber 5
2 Thermocouple Locations 6
3 Flowmeter Versus Weir Equation 13
4 Discrete Sample Temperature Versus Time (Chamber
Temperature at 33°C) 15
5 Discrete Sample Temperature Versus Time (Chamber
Temperature at 19°C) 16
LIST OF TABLES
No. Page
1 Sampler Accuracy (Timed Runs) 9
2 Timed Multiplexer Operation 10
3 Flowmeter Accuracy 12
4 Spurious Cycles 18
5 21
thru Timed Tests (Appendix) thru
12 24
13 25
thru Flowmeter Tests (Appendix) thru
21 30
VI
-------
SECTION I
CONCLUSIONS
The ISCO model 1391 sampler has an accurate timer. Timer precision
is excellent for runs that are in multiples of 1 hour, however pre-
cision of other runs was not as good (approximately ą1 minute) and
this variation is due to the manufacturer's method of initiating a
signal from the timer. Existing precision is satisfactory for
routine sampling; however, in special cases, such as litigation
procedures, better precision may be required.
Occasionally spurious cycles occurred, which were caused by con-
tact bounce of the timer actuated reed switch.
Volume of sample collected was satisfactory and variation in
sample size was not excessive.
Multiplexer operation was satisfactory.
Flowmeter performance was satisfactory after calibration. Ac-
curate calibration should take place at the factory. Flowmeter
precision decreases with decreasing flows and is inherent for this
type meter.
These runs showed no difference in operation between converter or
battery power. Endurance tests showed that the company's claim
for the sampler operation (collecting 100 samples of 500 ml each)
was exceeded.
Thermocouple readings on discrete samples showed the company's
claim of maintaining samples 22.2C below ambient for 24 hours is
not always correct.
The pump did not reverse for eight samples of a low-temperature,
high-humidity run. Changing the desiccant may have eliminated
this problem.
-------
SECTION II
RECOMMENDATIONS*
The model 1391 has many desirable features and would be satisfac-
tory for routine sampling. Although existing timer precision is
probably better than many other samplers on the market, improve-
ment is still warranted. The possibility of taking a spurious
sample should be eliminated. This could be accomplished by elimi-
nating the reed switch and incorporating solid state logic circuits.
Improvement in flowmeter precision at the low cam setting should be
developed. A one-time factory flowmeter calibration is required.
Desiccants can be burdensome, and samplers should be developed to
perform satisfactorily without them. The sampler compartment
should be kept light in weight and dimensionally small; however,
better insulation and a larger ice space is required to keep iced
samples for 24 hours when ambient temperatures are high.
The ISCO has many excellent features, and hopefully these recom-
mendations will aid in the further development of water samplers.
*Correspondence from ISCO (November 20, 1974) states that the
company markets a (model 1580) sampler that utilizes solid state
programming electronics and that in time all ISCO samplers will
utilize solid state programming electronics. This will replace
the mechanical clock and programming relays including the reed
switch. ISCO also stated that the problem experienced with the
15-minute timer on the model 1391 is not at all characteristic.
A defective reed switch would usually show up during ISCO's quality
assurance program checks and it would be replaced at that time.
ISCO has also gone to a more sensitive and reliable reed switch
for both the 15-minute and 10-minute timers.
-------
SECTION III
DESCRIPTION OF SAMPLER
This report summarizes an evaluation of the ISCO water and waste-
water sampler, which includes the following components:
1. Model 139IX sampler with 115 VAC/12 VDC power converter
battery charger
2. Model 1392 Nicad battery pack (rechargeable)
3. Model 1406W high density polyethylene sample bottles (28
required)
4. Model 1397W 15-minute timer in place of standard 30-
minute timer
5. Model 1398W multiplexer
6. Model 1470W flowmeter with 0- to 6-inch range and cali-
bration disc for 90° sharp crested V-notch weir
7. Model 1396W suspension harness
Sampler weight is 40 pounds (18.16 Kg), not including the flow-
meter.
This sampler will take up to 28 discrete samples. With the mul-
tiplexer, each discrete sample can be made up of from 1 to 4
aliquots. Aliquots may be timed from 15 minutes to 3 hours apart.
For example, the device could be programmed to collect three 15-
minute aliquots per discrete sample, and therefore the 28 bottles
would be filled in 21 hours.
Power requirement is 12 VDC, which can be obtained from ISCO's 115
VAC/12 VDC power converter, their Model 1392 Nicad battery pack,
or an automobile battery. The Nicad battery can be recharged with
the power converter (time to full recharge is 14 hours).
The unit's electronic circuitry is transistorized and uses
amplifier-driven relays incorporating switching and shunting tran-
sistor circuits. A multivibrator homes stepper relays after each
cycle. One time-proportioned runs, the circuit is activated by a
magnetically controlled reed switch. A four-lobe magnet mounted
on the end of the clock shaft closes the reed switch four times per
hour.
The unit tested included the Model 1470 flowmeter with 0- to 6-
inch range and program disc for a 90° sharp crested V-notch weir.
-------
This flowmeter is mounted upstream from a V-notch weir and will
actuate the sampler proportional to flow. Sample size remains
constant, but time between samples varies. The multiplexer may
also be used with the flowmeter, allowing up to 4 aliquots per
discrete sample. Flowmeter electronics includes a pulse generator,
which delivers a 13.66 Hz signal whenever the float-driven stylus
is in contact with the conductive portion of the disc. This signal
enters a binary counter that triggers a 12-volt signal after a
specified number of pulses determined by the range-switch setting.
This 12-volt signal which is proportional to flow, will now actuate
the sampler instead of the clock-activated reed switch mentioned
in the previous paragraph. Complete operational descriptions,
including circuit diagrams, are provided by the manufacturer with
instrument purchase.
-------
SECTION IV
METHOD OF TESTING AND EQUIPMENT USED
Testing took place in the laboratory under ambient conditions and
also within an environmental chamber at temperatures of 2, 19, and
35C. When the environmental chamber was used for time-controlled
runs, both the sampler and water tub were located within the cham-
ber. For flowmeter-controlled runs, the sampler and flowmeter
were located within the chamber, but lack of space made it nec-
essary to place the water tub outside. Therefore, during all
flowmeter runs, the sample water temperature was maintained at
ambient (about 20C). Lift from the water tub to the pump inlet
was maintained at 3 feet (91.4 cm) for all runs. Flowmeter runs
were made under static conditions with the meter mounted on a tub
of still water. Float settlings were adjusted by varying the
water level within the tub. Figure 1 illustrates the setup for
testing the flowmeter/sampler combination within the environmental
chamber.
r
ENVIRONMENTAL CHAMBER
91.4cm
^INTAKE
Figure 1. SCHEMATIC DIAGRAM OF FLOWMETER/SAMPLER TESTS
WITHIN THE ENVIRONMENTAL CHAMBER
-------
Some of the environmental chamber runs were made to show preser-
vation ability, and therefore thermocouples were located inside
eight of the 28 sample bottles. Thermocouple locations are
shown in Figure 2. Before these runs, the center of the sample
container was filled with ice and enough water to cover the lower
portion of the bottles.
2.8 27
26
25
24
23
20
19
10
18
11
17
12
13 14 15
Fig.2 Thermocouple locations.
Equipment used for the sampler evaluation is as follows:
1. Honeywell Electronic 16 recorder (span to 12 volts with
suppression)
2. Esterline Angus recorder (span to 100 volts)
3. Honeywell Electronic 16, 12 point thermocouple recorder
4. Webber Manufacturing Company, Inc., environmental chamber
5. Resistance decades
-------
6. Tektronix Model 454A oscilloscope
7. Matheson thermometer, -1 to 51C, 1/10 division
8. Various graduates and flasks
Recorders (other than temperature) were used to monitor voltages
across the pump motor (C12) and after the reed switch (across R4).
Components C12 and R4 are shown in the manufacturer's circuit
diagram, which is not included in this report. The C12 trace gave
an accurate record of pump operation (forward and reverse) versus
time. The R4 trace gave an accurate record of either the reed
switch movement or the flowmeter signal, residual voltages, and
also pump operation versus time. Oscilloscope observations in-
cluded the multivibrator signals, flowmeter frequency, and various
voltage levels within the electronics. Various flasks and gradu-
ates were used to measure the sample volumes collected.
-------
SECTION V
RESULTS OF PERFORMANCE TESTS
TIMED RUNS
Accuracy of the timing function and volume delivery was tested at
approximately 2, 19, and 35C. Table 1 summarizes this part of the
original data, which are included as Tables 5 through 12 of the
Appendix. For example, Table 1 shows that run no. 5 was made with
the sampler and water bath in the environmental chamber at 1.7C.
Average volume (X) of the 28 bottles collected was 440.5 ml
(standard deviation Sx, = 2,33 ml), and average time (t) between
bottles was 44.99 minutes (St = 0.809 minute). Sampler settings
were 420 ml and 45 minutes for volume and time, respectively. For
this run, the average volume collected was satisfactory and volume
variation was not excessive. Average time between samples (44.99
minutes) is near perfect, hence the clock is an accurate timing
device; however the standard deviation of 0.809 minutes shows a
lack of precision. This variation in time between discrete sam-
ples can be seen in Table 9 of the Appendix. Time variation is
caused by the four-lobe magnet (described earlier) that closes a
reed switch and initiates a pulse four times per hour. Better
time precision between samples can be maintained if each lobe were
exactly 90° apart, with precise magnetic field intensity. Table
1, run no. 3, shows a run set to collect samples 60 minutes apart.
Here, each cycle was initiated by the same magnet lobe after 360°
of rotation, and excellent precision (St = .021) is maintained.
Discrete sample time variation for this run can be seen in Table 7
of the Appendix.
Run no. 8 in Table 1 shows a volume standard deviation of 6.3 ml.
This is higher than for other runs and was probably caused by im-
proper placement of the sample line. The line should be installed
with a slight downward slope from the sampler to the source. This
point is mentioned by the manufacturer in his instruction manual.
Multiplexer operation on a timed cycle was checked at ambient con-
ditions (approximately 20C). The sampler was programmed to collect
three 140-ml aliquots per bottle at 15 minute intervals. Therefore,
the distribution funnel indexes to the next bottle every 45 minutes.
Table 2 illustrates this run. Average sample volume of 424.7 ml
is satisfactory when compared to the setting of 420 (3 x 140).
-------
Table 1. SAMPLER ACCURACY (TIMED RUNS)*
Run
no.
Temp.
(°C) Set
Volume
X
(ml)
Sx (ml)
Set
t
Time
(min) J
5t (min)
115 VAC/12 VDC Converted
5
8
2
6
3
1
1.7
19.4
21.0
32.8
22.0
21.0
420
420
210
420
210
210
440.5
440.1
220.6
441.4
216.4
219.5
2.33
6.30
1.81
2.331
1.069
2.13
45
45
45
45
60
15
44.99
45.00
45.01
44.99
59.99
15.00
0.809
0.823
0.560
0.828
0.021
0.557
12 V Battery
4
7
1.7
34.7
420
420
438.6
437.4
3.56
2.329
45
45
45.00
45.00
0.828
0.836
*Averages (X and t) and standard deviations (Sx and
calculated from 28 samples.
were
Sample variation (Std. Dev. = 1.63) is not excessive. Timer accu-
racy was satisfactory with an average interval between aliquots
of 15 minutes and average time per sample of 45 minutes. Time
variation, again caused by the magnet lobes, can be improved.
FLOWMETER
The flowmeter/sampler combination was tested on both converter and
battery power at temperatures of approximately 2, 19, and 35C.
The multiplexer was also used on some of these runs. Table 3 sum-
marizes the original flowmeter data, which are included as Tables
13 through 21 of the Appendix. As an example, run no. 9 in Table
3 shows that the sampler was set to collect 280 ml per bottle
after each 4,000 gallons of flow passed over the weir. Twenty-
eight samples contained an average of 302.1 ml, with a standard
deviation of 1.88 ml; hence sample volume is satisfactory and
variation is not excessive. Average time between samples was
37.71 minutes, giving a flowmeter reading of 106.1 gpm. Flow
calculated from the weir equation (Q = 5/2H5/^) was 113.5 gpm,
-------
Table 2. TIMED MULTIPLEXER OPERATION*
Aliquot
#1
15. 50t
14.55
15.80
14.10
15.40
14.45
15.75
14.25
15.55
14.45
15.85
14.30
15.50
14.50
15.80
14.15
15.50
14.45
15.80
14.20
15.45
14.55
15.80
14.20
15.55
14.50
15.70
14.45
Avg = 15.00
S = .668
Time
Aliquot
#2
14.25
15.55
14.45
15.95
14.15
15.55
14.50
15.85
14.10
15.50
14.50
15.70
14.20
15.55
14.45
15.80
14.20
15.50
14.55
15.85
14.20
15.55
14.45
15.80
14.20
15.50
14.55
15.80
15.007
.699
(min)
Aliquot
#3
15.85
14.15
15.55
14.45
15.85
14.20
15.50
14.45
15.80
14.15
15.35
14.50
15.80
14.20
15.50
14.55
15.80
14.20
15.45
14.55
15.75
14.20
15.55
14.50
15.70
14.30
15.50
14.55
14.996
.675
Sample
Total
45.60
44.25
45.80
44.50
45.40
44.20
45.75
44.55
45.45
44.10
45.70
44.50
45.50
44.25
45.75
44.50
45.50
44.15
45.80
44.60
45.40
44.30
45.80
44.50
45.45
44.30
45.75
44.80
45.005
.649
Volume
(ml)
425
423
425
423
423
424
421
425
423
424
425
423
425
425
423
424
426
425
424
426
427
425
429
425
425
427
427
425
424.7
1.63
*Sampler programmed to collect three 140 ml aliquots per bottle at
15-minute intervals.
tEstimated.
10
-------
using the head of 0.4 foot. This differs from the manufacturer by
6.5 percent and exceeds their 5 percent claim. The manufacturer
suggested adjusting the unit if necessary so that the stylus just
touches the disc conductor when the-meter reads zero. The manu-
facturer's setting was slightly low, so the adjustment was made.
Table 3 shows that the adjustment was beneficial, except that the
very lowest readings (runs 17 and 18) were then slightly high.
Figure 3 illustrates the flowmeter versus weir equation before
and after the zero adjustment. This adjustment is hard to set
because it is in a confined area and should be made at the factory.
Table 3 shows that the standard deviation (St) for time between
samples gets larger as flow decreases. This is inherent for this
type of flowmeter, that incorporates a 13.66 pps signal that is
being generated and integrated only while the stylus makes con-
tact with the disc conductor. Contact time per disc revolution
becomes proportionately less as flow decreases.
Table 3 shows that multiplexer operation (run nos. 11, 12, 13) on
flow-proportional runs is satisfactory for volumes and volume
variation. Flowmeter accuracy for these runs was discussed above.
BATTERY OPERATION AND ENDURANCE
Table 1 (timed runs) and Table 3 (flowmeter runs) show that the
difference between converter and battery operation is not signi-
ficant. Satisfactory operation should therefore be expected when
operating on either converter or battery power for both timed and
flowmeter runs.
The 1392W nickel-cadmium battery supplied by ISCO was tested for
compliance with their claim (100 samples of 500 ml each after a
14-hour recharge). The battery was recharged for more than 14
hours before starting the endurance tests. The sampler was
placed at a lift of 3 feet (91.44 cm) and set to collect 490 ml
samples at 15-minute intervals. These tests showed that the
battery operated the unit through nine complete runs with over
500 ml per sample being collected (252 samples). Battery endur-
ance therefore exceeded the company's specification and is
satisfactory.
TEMPERATURE PRESERVATION
ISCO's sample bottle tub incorporates an inner and outer liner
11
-------
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12
-------
&
o>
150
125
100
75
50
25
BEFORE ZERO
ADJUSTMENT
RAFTER ZERO
°> ADJUSTMENT
25
125
150
50 75 100
WEIR EQUATION, gpm
Figure 3. FLOWMETER VERSUS WEIR EQUATION
13
-------
separated by polyurethane foam insulation. As mentioned earlier
(Figure 2), these tests were made with thermocouples located in
bottle numbers 1, 2, 8, 9, 15, 16, 22, and 23, and the center of
the container was packed with ice. Sample temperatures are
plotted versus time in Figures 4 and 5 for environmental chamber
runs at 33 and 19C, respectively. Figure 4 shows sample tempera-
tures decreasing with time and then increasing as the ice melted.
A minimum temperature of about 7C is shown in Figure 4 and a
minimum of about 4C is shown in Figure 5. The fact that some
samples (such as no. 9 in Figure 4) show the temperature decreasing
immediately (from 31 to 5.5C) indicates that the thermocouple was
probably resting against the side of the bottle. The more gradual
slope shown for most samples is a truer picture of sample water
temperature. Company claims are that the sampler, when packed
with ice, will hold samples 22.3C below ambient for 24 hours.
Figure 4 shows that this claim is not necessarily true. EPA
methods* require a preservation temperature of 4C for some mea-
surements .
""'Methods for Chemical Analysis of Water and Wastes," Environmental
Protection Agency, NERC, AQCL, Cincinnati, Ohio, 1971.
14
-------
#22
o
0.
#23
APPROXIMATELY 700 MIN
I i I i I i I
0 100 200 300 400 500 600 700 800 900 1000 1100 1200
ELAPSED TIME (MIN)
FIG. 4 DISCRETE SAMPLE TEMP VS. TIME
(CHAMBER TEMP. AT 33°C)
15
-------
251-
#22 #23
ICE LASTED APPROXIMATELY 1200 AAIN.
I i I i I i I i I i I i I i I t I i I i I i I
100 200 300 400 500 600 700 800 900 1000 1100 1200
ELAPSED TIME (MIN)
FIG. 5 DISCRETE SAMPLE TEMP. VS. TIME
(CHAMBER TEMP. AT 19°C)
16
-------
SECTION VI
PROBLEMS
SPURIOUS CYCLES
A few spurious cycles occurred when these tests were initiated.
The problem was traced to the magnetically actuated reed switch,
which closes every 15 minutes, stays closed for about 10 minutes,
and then reopens. At times, just after reopening, the reed
switch reclosed and initiated a spurious signal. Table 4 illus-
trates this phenomenon occurring during a run with the multiplexer
and timer set on 3 and 15 minutes, respectively. In this instance,
two aliquots are taken within the 15-minute time period, and every
aliquot thereafter is taken 15 minutes earlier. This problem was
intermittent; and after inspecting the magnet and reed switch and
reinstalling them, it did not reoccur. A slightly different
positioning of these components may have inadvertently corrected
the problem, however these components should be redesigned so
that the problem never occurs.
PUMP REVERSAL
One run occurred in which the pump did not reverse for the first
eight samples (Appendix Table 18), and the bottles therefore over-
flowed. This run was made using the flowmeter and sampler within
the environmental chamber at 2C. Relative humidity within the
chamber was approximately 100 percent. Moisture may have caused
the problem, since the desiccant was changed after the run, and
the problem did not reoccur. Samplers should be designed to work
properly without the use of desiccants because it is too easy to
forget to change them.
SUSPENDED SOLIDS
The sampler incorporates an inlet strainer that is a cylinder (1
inch [2.54 cm] ID and 5 inches [12.7 cm] long). The cylinder has
four rows (90° apart) of five 1/4-inch (.635 cm) diameter holes.
Either 3/8- or 1/4-inch diameter tubing is used to carry the sam-
ple from the strainer to the unit. Average velocity within the
1/4-inch line was measured with a stop watch at 0.79 (24.08 cm)
per second. Suspended solids of an organic nature should stay in
suspension at this velocity. Velocity through each of the 20
strainer holes would be 1/20 of 0.79 foot per second, and the
17
-------
Table 4. SPURIOUS CYCLES*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Aliquot
#1
14.35t
15.9
14.3
15.35
14.35
15.85
14.4
15.4
14.3
15.9
14.4
5.65]
15.9
14.35
15.4
14.35
15.85
14.35
14.35
15.9
14.4
14.4
15.9
14.5
15.35
14.4
15.8
14.4
Time
Aliquot
#2
15.4
14.3
15.9
14.4
15.35
14.35
15.85
14.45
15.4
14.3
15.85
15.45
14.3
15.9
14.35
15.45
14.35
[ 9.95
15.4
14.45
[9.85
15.35
15.85
14.45
15.3
14.4
[ 9.8
(min)
Aliquot
#3
14.4
15.5
14.3
15.85
14.45
15.35
14.35
15.8
15.45
[ 8.7
14.3
15.45
14.35
15.85
14.35
15.4
5.95]
15.35
6.0]
14.4
15.25
14.4
15.8
14.45
15.35
6.0]
Sample
total
44.15
45.70
44.50
45.60
44.15
45.55
44.60
45.65
45.65
38.95
35.40
45.65
44.60
45.60
44.15
45.60
30.25
45.70
30.25
44.15
44.75
45.60
44.15
45.55
30.20
*Brackets show where two aliquots were taken during a 15-minute
period. The sampler was programmed to take one aliquot every
15 minutes.
tEstimated.
18
-------
velocity within the 1-inch ID strainer is also proportionately
lower than 0.79. Accurate suspended solids samples could probably
be obtained if the strainer were removed and the 1/4-inch tube
opening .directed toward the flow. Recently ISCO came out with a
model 1392 sampler which pumps at a rate four times faster than
the model 1391.
19
-------
SECTION VII
DISCUSSION
Performance was satisfactory during most of these tests. Weight
and dimensions make the sampler easy to handle and adaptable to
most locations, including manholes. The control function is pro-
fessionally designed and neatly assembled, using transistorized
circuitry mounted on printed circuit boards. Greater use of
"plug-in" components and circuits should be incorporated. Al-
though the electromechanical switches performed satisfactorily,
except for the reed switch, one may consider replacing these com-
ponents with integrated solid state logic circuits. Components
should be designed for operation in humid environments, and
desiccants should be eliminated. The small, light-weight, re-
chargeable battery performed well and is a desirable feature. An
event recorder should be included to mark the time that the sample
was taken on both time- and flow-proportioned runs. The manufac-
turer's instruction manual is thorough, includes circuit diagrams,
and is easy to follow. In general, the model 1391 is an above-
average sampler, and it is hoped that the recommendations made in
this report will be considered objectively.
20
-------
SECTION VIII
APPENDIX
Table 5. TIMED TESTS, RUN #1*
Table 6. TIMED TESTS, RUN #2*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
15.75t
14.50
15.25
14.50
15.75
14.50
15.30
14.50
15.75
14.50
15.25
14.50
15.75
14.50
15.30
14.40
15.80
14.50
15.30
14.45
15.75
14.50
15.25
14.50
15.85
14.45
15.20
14.50
Volume
x (ml)
220
222
219
220
221
218
221
221
217
216
216
218
219
221
219
219
222
218
221
222
217
216
221
222
221
222
216
222
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
45.50t
45.50
44.20
45.60
45.50t
44.25
45.40
44.70
45.50
44.25
45.50
44.80
45.50
44.20
45.50
44.75
45.50
44.25
45.50
44.70
45.50
44.20
45.50
44.70
45.50
44.20
45.50
44.70
Volume
x (ml)
218
222
221
222
223
221
219
217
221
222
218
220
222
222
221
218
218
221
222
220
221
222
220
222
218
224
222
219
Total 420.05
t = 15.00 x = 219.50
St = 0.557 Sx = 2.13
Total
1260.40
t = 45.01 x = 220.60
St = 0.560
Sx = 1.814
*Room temperature is 21°C;
water temperature is 18°C.
tEstiraated.
*Room temperature is 21°C;
water temperature is 18°C.
tEstimated.
21
-------
Table 7. TIMED TESTS, RUN #3*
Table 8. TIMED TESTS, RUN #4*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
60. Ot
60.0
60.0
60.0
60.0
60.0
60.0
59.95
60.0
60.0
60.0
59.95
60.0
60.0
59.95
60.0
60.0
60.0
60.0
59.95
59.95
60.0
60.0
59.95
60.0
60.0
60.0
60.0
Volume
x (ml)
218
218
216
217
217
217
217
216
218
216
215
216
215
216
217
217
215
216
216
214
218
215
216
218
217
216
217
216
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
44.lt
45.7
44.3
45.9
44.1
45.6
44.5
45.7
44.3
45.8
44.2
45.8
44.1
45.8
44.3
45.8
44.1
45.7
44.3
46.0
44.0
45.8
44.3
45.8
44.1
46.0
44.1
45.9
Volume
x (ml)
440t
440
455
437
439
440
439
439
439
440
437
435
436
437
440
437
437
438
437
438
439
437
438
434
438
439
438
437
Total
1679.7
Total
1260.1
t = 59.99 x
St = 0.021
= 216.4
Sx = 1.069
*Room temperature is 22°C;
water temperature is 19°C.
tEstimated.
t = 45.00 x = 438.6
St = 0.828 Sx = 3.56
*Chamber temperature is 2°C;
water temperature is 3°C.
Battery power.
tEstimated.
22
-------
Table 9. TIMED TESTS, RUN #5*
Table 10. TIMED TESTS, RUN #6*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
44. 2t
45.7
44.1
46.0
44.2
45.8
44.0
46.0
44.2
45.8
44.0
45.8
44.4
45.7
44.1
46.0
44.0
46.0
44.0
46.0
44.2
45.8
44.0
46.0
44.2
45.8
44.0
45.7
Volume
x (ml)
445
438
440
441
440
441
438
438
441
440
441
437
440
438
443
442
440
441
438
437
442
439
438
442
445
441
443
445
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
45. 7t
44.0
46.0
44.2
45.9
43.9
45.9
44.5
45.7
43.9
45.9
44.4
45.7
44.1
45.7
44.3
45.7
44.0
45.8
44.4
45.8
44.0
45.8
44.5
45.5
44.0
45.8
44.5
Volume
x (ml)
440t
445
443
443
444
443
444
440
444
444
438
440
442
440
443
439
435
444
443
439
441
440
440
439
442
440
441
443
Total
1259.7
t =44.99
St = 0.809
X =
440.5
2.33
*Chamber temperature is 2°C;
water temperature is 3°C.
tEstimated.
Total
1259.6
= 44.99
= 0.828
= 441.4
2.331
*Chamber temperature is 33°C;
water temperature is 30°C.
tEstimated.
23
-------
Table 11. TIMED TESTS, RUN #7*
Table 12. TIMED TESTS, RUN #8*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
44. 3t
45.8
44.0
45.9
44.3
45.8
44.2
45.9
44.4
45.7
44.2
48.0
45.1
46.2
44.0
45.9
44.3
45.7
44.0
46.0
44.2
45.8
43.9
45.9
44.4
45.6
44.2
45.8
Volume
x (ml)
440t
440
440
434
438
439
440
433
441
436
439
437
440
438
438
434
435
438
436
436
437
433
439
435
436
436
438
440
Sample
number
' 1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Cycle time
t (min)
45 . 75t
44.2
45.8
44.3
45.8
44.2
45.7
44.3
45.7
44.2
46.0
44.3
45.6
44.0
45.9
44.2
45.8
44.1
45.9
44.2
45.8
44.1
45.9
44.2
45.8
44.1
45.8
44.4
Volume
x (ml)
440t
445
435
441
443
442
438
455
436
436
455
441
440
458
434
437
436
434
438
436
440
438
435
438
437
443
435
438
Total
1260.1
Total
1260.05
t = 45.00
S+ = 0.836
x =437.4
Sx = 2.329
*Chamber temperature is 35°C;
water temperature is 33°C.
Battery power.
tEstimated.
= 45.00 x = 440.1
St =
0.823 Sx = 6.299
*Chamber temperature is 20°C;
water temperature is 20°C.
tEstimated.
24
-------
Table 13.
FLOWMETER TESTS,
RUN #9*
Table 14.
FLOWMETER TESTS,
RUN #10*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
t
st
Cycle time
t (min)
~ _ Ť _
37.8
37.5
37.8
37.9
37.8
37.7
37.5
38.0
37.7
37.6
37.7
37.8
37.5
37.7
37.6
37.7
38.2
37.5
37.6
37.7
37.7
37.6
37.7
37.7
37.7
37.7
37.7
1018.1
= 37.71 x
= 0.154 Sx
Volume
x (ml)
307
300
301
302
300
303
302
303
302
299
300
302
303
304
303
302
304
303
300
303
300
300
300
301
304
305
304
303
302.1
1.88
*Flowmeter setting = 4000 gal/
sample. Head = 0.4 ft.
Flowmeter gave 106.1 gal/min.
Weir equation gave 113.5 gal/
min. Room temperature = 21°C,
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
Cycle time
t (min)
_
9.7
9.55
10.3
9.45
9.65
9.65
9.55
9.55
10.35
9.5
9.6
9.6
9.55
9.55
9.55
10.3
9.6
9.65
9.55
9.55
9.6
9.5
10.35
9.55
9.55
9.55
9.65
261.5
t =9.685 x
St = 0.277 Sx
Volume
x (ml)
303
304
303
303
304
303
303
302
303
303
303
302
303
303
302
303
301
303
303
303
302
303
302
302
301
303
301
302
= 302.61
0.786
*Flowmeter setting = 500 gal/
sample. Head = 0.3 ft.
Flowmeter gave 51.63 gal/min.
Weir equation gave 55.21 gal/
min. Room temperature = 21°C.
25
-------
Table 15. FLOWMETER TESTS, RUN #11*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
Time
1st aliquot
t (min)
12.6
12.7
12.5
12.6
13.5
12.6
12.6
12.7
12.6
12.6
12.7
12.9
12.6
12.6
12.7
12.7
12.5
12.5
12.6
12.5
12.6
12.5
12.6
13.5
12.6
12.6
12.6
342.3
t = 12.68
St = 0.247
Time
2nd aliquot
t ("tin)
12.7
12.7
12.8
12.7
12.9
12.6
12.8
12.7
12.5
12.6
13.6
12.5
12.6
12.7
12.6
13.5
12.7
12.6
12.7
13.5
12.8
12.8
12.7
12.7
12.5
12.6
12.6
12.6
357.3
t =12.76
St = 0.290
Accumulative
time
t (min)
25.4
25.3
25.5
25.2
25.5
26.1
25.4
25.3
25.2
25.2
26.2
25.2
25.5
25.3
25.2
26.2
25.4
25.1
25.2
26.1
25.3
25.4
25.2
25.3
26.0
25.2
25.2
25.2
t = 25.44
St = 0.341
Volume
x (ml)
459
455
457
453
453
457
456
453
457
455
453
457
455
455
454
455
456
455
453
453
455
455
454
457
452
453
454
455
x = 454.86
Sx = 1.693
*Flowmeter setting = 250 gal/sample.
Head = 0.2 ft.
Flowmeter gave 19.65 gal/min.
Weir equation gave 20.2 gal/min.
Room temperature is 21°C.
26
-------
Table 16. FLOWMETER TESTS, RUN #12*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
Time
1st aliquot
t (min)
-. -
17.3
17.2
17.2
17.3
16.8
17.3
18.4
17.3
17.3
17.4
17.4
17.2
17.2
17.5
17.3
16.7
16.9
16.8
17.0
16.8
17.0
17.3
17.1
17.4
17.3
17.3
17.7
465.4
t = 17.24
St = 0.326
Time
2nd aliquot
t (min)
17.3
16.8
16.8
17.0
17.0
17.2
17.0
19.0
17.0
16.7
16.9
16.7
16.9
16.8
16.7
17.4
17.3
17.4
17.2
17.1
17.2
17.2
16.9
16.9
16.9
16.9
17.5
17.5
479.2
t = 17.11
St = 0.441
Accumulative
time
t (min)
34.6
34.1
34.0
34.2
34.3
34.0
34.3
37.4
34.3
34.0
34.3
34.1
34.1
34.0
34.2
34.7
34.0
34.3
34.0
34.1
34.0
34.2
34.2
34.0
34.3
34.2
34.8
35.2
t =34.35
St = 0.192
Volume
x (ml)
458
458
453
457
456
453
456
455
453
456
455
455
457
457
454
455
456
455
455
454
453
453
455
455
455
456
454
456
x = 455.18
Sv = 1.467
A.
*Flowmeter setting = 2000 gal/sample
Head = 0.4 ft.
Flowmeter gave 16.48 gal/min.
Weir equation gave 113.55 gal/min.
Calibration cam adjusted before run.
Battery power.
Room temperature is 21°C.
27
-------
Table 17. FLOWMETER TESTS, RUN #13*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
Time
1st aliquot
t (min)
.._.
19.0
17.5
17.6
17.6
16.8
17.6
17.0
17.4
17.4
17.5
17.3
17.5
17.6
17.7
17.7
17.3
17.9
17.2
17.8
17.3
17.5
17.3
17.4
18.0
17.1
17.5
17.7
473.2
t = 17.53
St = 0.388
Time
2nd aliquot
t (min)
18.1
18.5
17.1
16.9
17.6
17.4
17.4
17.6
17.5
17.1
17.5
17.5
17.2
17.2
17.1
17.2
17.3
17.3
17.5
17.2
18.0
17.4
17.8
17.1
17.5
17.9
17.3
17.3
488.5
t = 17.45
St = 0.352
Accumulative
time
t (min)
35.6
37.5
34.6
34.5
35.2
34.2
35.0
34.6
34.9
34.5
35.0
34.8
34.7
34.8
34.8
34.9
34.6
35.2
34.7
35.0
35.3
34.9
35.1
34.5
35.5
35.0
34.8
35.0
979.2
t = 34.97
St = 0.192
Volume
x (ml)
455
456
456
458
456
456
455
452
456
456
455
456
456
455
455
456
455
457
456
453
455
453
455
455
455
455
455
455
x = 455.29
SY = 1.182
.A.
*Flowmeter setting = 2000 gal/sample,
Head = 0.4 ft.
Flowmeter gave 114.38 gal/min.
Weir equation gave 113.55 gal/min.
Battery power.
Room temperature is 21°C.
28
-------
Table 18.
FLOWMETER TESTS,
RUN #15*
Table 19.
FLOWMETER TESTS,
RUN #16*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
t
St
Cycle time
t (min)
6.5
6.6
6.4
6.6
6.6
6.5
6.5
6.3
6.7
6.4
6.6
6.4
6.4
6.8
6.4
6.4
6.6
6.6
6.4
6.5
6.5
6.5
6.6
6.6
6.4
6.6
169.4
= 6.51 x
= 0.121 Sx
Volume
x (ml)
_
536
Samples
over-
flowed
because
pump
didn't
reverse.
372
367
373
371
372
373
371
372
372
372
371
370
372
370
370
373
372
374
373
= 371.56
1.617
*Flowmeter setting = 1000 gal/
sample. Head = 0.451 ft.
Flowraeter gave 153.48 gal/min.
Weir equation gave 153.27 gal/
min. Chamber temperature =
1.7°C. Relative humidity = 100%.
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
Cycle time
t (min)
6.6
6.7
6.5
6.5
6.4
6.4
6.5
6.7
6.5
6.5
6.4
6.6
6.5
6.5
6.4
6.6
6.6
6.6
6.5
6.3
6.6
6.6
6.5
6.3
6.6
6.6
6.5
176.0
t = 6.52
St = 0.102
Volume
x (ml)
366t
365
367
367
365
367
368
367
370
367
363
367
364
367
365
365
368
368
365
367
366
365
368
352
367
364
367
368
= 365.89
3.13
*Flowmeter setting = 1000 gal/
sample. Head = 0.451 ft.
Flowmeter gave 153.41 gal/min.
Weir equation gave 153.27 gal/
min. Chamber temperature =
1.1°C. Relative humidity =
100%. Sampler iced.
tEstimated.
29
-------
Table 20.
FLOWMETER TESTS,
RUN #17*
Table 21.
FLOWMETER TESTS
RUN #18*
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
t
st
Cycle time
t (min)
_ _
6.3
5.3
5.3
5.4
5.3
5.4
5.5
5.3
5.7
5.5
5.4
5.7
5.7
5.5
5.5
5.7
5.6
5.7
5.7
4.5
5.8
5.7
5.7
5.6
5.7
4.8
5.8
149.1
= 5.52 x
= 0.326 Sx
Volume
x (ml)
371t
373
373
373
374
371
369
370
371
371
371
370
370
372
370
370
370
371
370
371
370
368
372
370
372
371
370
371
= 370.89
1.315
*Flowmeter setting =62.5 gal/
sample. Head = .15 ft.
Flowmeter gave 11.32 gal/min.
Weir equation gave 9.78 gal/
min. Chamber temperature =
36°C. Relative humidity = 68%,
tEstimated.
Sample
number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Total
t
st
Cycle time
t (min)
_
4.8
6.0
4.7
4.8
6.0
5.0
6.0
4.7
5.0
6.1
4.8
4.8
6.0
4.8
6.0
4.9
4.8
6.1
4.9
5.0
5.8
4.9
5.0
6.1
4.9
5.9
5.0
142.8
=5.29 x
= 0.554 Sx
Volume
x (ml)
369t
369
373
370
370
370
371
370
370
371
368
367
372
369
369
370
369
368
369
369
370
368
370
367
370
369
370
367
= 369.43
1 . 399
*Flowmeter setting =62.5 gal/
sample. Head = 0.15 ft.
Flowmeter gave 11.81 gal/min.
Weir equation gave 9.78 gal/
min. Chamber temperature =
35°C. Relative humidity = 70%.
Sampler iced. Battery power.
tEstimated.
30
-------
TECHNICAL REPORT DATA
/Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA-670/4-75-001
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE AND SUBTITLE
PERFORMANCE OF THE ISCO MODEL 1391 WATER AND
WASTEWATER SAMPLER
5. REPORT DATE
February 1975; Issuing Date
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
Richard P. Lauch
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
National Environmental Research Center
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
10. PROGRAM ELEMENT NO.
1HA327; ROAP 24ALE; TASK 03
11. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
Same as above
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
16. ABSTRACT
Performance of the ISCO model 1391 water samt>ler was tested. Tests were run at
2, 19, and 35C to check accuracy and precision of the timer, flowmeter, and
sample volumes. The multiplexer function of delivering multiple aliquots per
bottle was tested. Performance checks were made on both converter and battery
power, and battery endurance was determined. Discrete sample temperatures were
recorded versus time under iced conditions. Manufacturer's claims were mostly
confirmed, but improvement is warranted for some sampler components.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS C. COSATI Field/Group
Samplers, Water pollution, Acceptance
sampling, Continuous sampling, Data
sampling, Sequential sampling
Sampler evaluation,
Evaluation, Sewer sam-
pler evaluation, Effluent
sampler evaluation, Water
sampler evaluation, Water
sampler
13B
18. DISTRIBUTION STATEMENT
Release to public
19. SECURITY CLASS (ThisReport)'
Unclassified
21. NO. OF PAGES
37
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220-1 (9-73)
31
U.S. GOVERNMENT PRINTING OFFICE: 1975-657-590/5336 Region No. 5-11
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