ISCO 6700SR, Instruction Manual, Page: 61 / 190

6700SR Refrigerated Sampler
43
Thread the discharge tube through the hole in the lid. Always use
the lid to retain the discharge tube. It prevents the sampler from
spraying liquid inside the sample compartment instead of the bottle.
Suction Line
The suction line is the tubing from the sampling point to the pump
intake. The 6700SR can use
3
/
8
inch ID suction lines of lengths from
3 to 99 feet. Isco offers vinyl or Teflon suction lines. The Teflon has
a polyethylene jacket to protect it from kinks and abrasions.
Guidelines for Measuring and Cutting Suction Line
Cut the line to the desired length but use the shortest length feasi-
ble for the installation.
Cut the line in 1 foot increments - for instance 4 feet, not 3 feet. Do
not include the length of the strainer in the measurement. If using
metric units of measure, cut the line in increments of 0.1 meter.
Attaching Suction Line to the Pump Tube
Attach the vinyl suction line to the pump tube with the tube cou-
pling. Use the black clamp for the pump tube and the white clamp
for the suction line. Attach the line and tube to the coupling by
pushing them onto each end of the coupling. Then tighten the
clamps by squeezing the finger pads together. Loosen a clamp by
twisting it until its teeth disengage.
Attach the Teflon suction line to the pump tube by inserting the
line into the tube and secure with a suitable clamp.
Strainers
Isco offers four strainers that help prevent solids from clogging the
suction line:
• Stainless steel strainer for priority pollutant sampling.
• Polypropylene strainer for routine sampling conditions.
• CPVC strainer for acidic liquid sources.
• Stainless steel low-flow strainer.
To select the right strainer for your application, refer to Table 7 .
Debris Deflector
A debris deflector prevents debris from accumulating on the hose
damp that attaches the strainer to the suction line.
Alternative to Strainers
When sampling from high velocity streams with heavy suspended
solids, some field investigations suggest that more representative
samples are obtained without the strainer. Consider attaching a
short piece of thin walled aluminum tubing to the end of the suction
line; anchor the tubing so that the inlet opens upstream. The alu-
minum tubing’s thin wall won’t disturb the flow stream, and most
sample analyses disregard aluminum ions. Under most conditions,
the presample purge removes any debris over the tubing entrance.
About Suction Lines
• The vinyl line contains a very low
parts-per-million level of phenols.
If phenol content affects your
sample analysis, use the Teflon
suction line.
• Occasionally, your sampling
application may suggest a
nonstandard line. For best
sampling results, however, use
the standard suction line available
from Isco.
• When installing the sampler, be
sure the vertical distance between
the liquid level and the pump is as
small as possible.
Attaching Suction Line
Tube Coupling
Attaching the
Debris Deflector