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3700 Portable Samplers
Section 1 Introduction
1.2.7 Foreign Languages and
Metric Units of
Measure
1.3 Delivery System
1.3.1 Liquid Detector
1.3.2 Pump Tubing and
Suction Lines
1-6
The 3700 Series samplers provide displays in French, German,
and Spanish. Additionally, the software supports entries in
metric units of measure. Samplers using French and German
language displays support metric units for suction-line and
suction-head measurements. Metric units include volumes in
milliliters, suction-head and suction-line length in decimeters,
and suction-line inside diameter (ID) in millimeters.
Samplers with English displays support either English or metric
units for suction-line and suction-head measurements. (Sample
volume units are always entered in milliliters, regardless of the
selected language.)
The 3700 Series uses a peristaltic pump for sample collection.
The sample is under pumped flow at all times; there are no
metering chambers and no gravity-fed internal tubing. Each
sampling cycle includes an air pre-sample purge and post-sample
purge to clear the suction line both before and after sampling.
These features make the 3700s ideal for both "suspended solid"
and "toxic material" sampling. Cross contamination between
samples is minimized, and sites for sediment accumulation in the
system are eliminated. Materials in contact with the sample fluid
are limited to the strainer, suction line, pump tubing, and col-
lection bottles. You can easily and safely clean the system by
replacing relatively inexpensive lengths of tubing.
Pump speed is approximately 250 RPM, which generates a
velocity sufficient to obtain representative samples. The
pumping rate of 3,500 ml per minute is generated when using
3
/
-inch ID suction line at 3 feet of head. The line transport
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velocity, using the same suction line and head, is 2.9 feet per
second. Pump speed does not significantly affect volumetric
accuracy because the delivered volume is based on a patented
electronic count of the number of pump revolutions.
The LD90 gives the 3700s the ability to deliver accurate,
repeatable sample volumes regardless of changing head condi-
tions. Typical sample volumes are accurate to within 10% of the
programmed volume and repeatable to within ± 10 ml. When
concerns of cross-contamination arise, the detector and a pro-
grammable setting provide for automatic rinsing of the suction
line. A programmable setting for sampling retries is available. If
the suction line becomes clogged and no liquid is detected in the
line, you can program the sampler to repeat a purge cycle – as
many as three times – to clear the clogged line.
The pump tubing is Silastic medical-grade silicon rubber. Liquid
is transferred from the source to the pump through either
3
3
/
-inch ID vinyl or
/
8
8
easily replace the pump tubing and suction lines, minimizing the
need for cleaning. The sampler automatically monitors pump
tubing wear: a tubing warning indication appears when the
pump-revolution count exceeds a user-specified wear limit.
-inch ID PTFE suction tubing. You can
1
/
- or
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