MIL-HDBK-1005/16
a)
Place the sampler below the freezing level or in
an insulated box.
b)
When AC is available, use a light bulb or heating
tape to warm the sampler. When installation below the freezing
level is not possible and line current is available, wrap 4 to
6 feet (1.2 to 1.8 m) heat tapes (thermostatically protected 38F
[3C]) around the sample bottle and the intake lines. Loosely
wrap a large 10-mil plastic trash bag over the heat tape on the
intake lines. Place a large plastic bag over the sampler as
loosely as possible.
c)
Place the line vertically or at such a slope to
ensure gravity drainage back to the source. Even with a back-
purge system, some liquid will remain in the line unless gravity
drainage is provided. If an excess length of tubing exists, cut
it off. Keep all lines as short as possible.
d)
Do not use catalytic burners to prevent freezing
since vapors can affect sample composition. When power is
unavailable, use a well-insulated box containing the sampler, a
battery, and a small light bulb to prevent freezing.
11.6.4
Selection of an Automatic Sampler. To choose an
automatic sampler, list the desired features needed and select
the sampler that best fits the requirements consistent with the
sampling objectives. Following is a list of features to be
considered in selecting an automatic sampler:
a)
Vertical lift
b)
Submergence
c)
Explosion proof
d)
Intake tube:
diameter/material
e)
Dissolved gases
f)
Suspended solids
g)
Oils and grease and floating material
h)
Materials:
organic pollutants
i)
Isokinetic sampling
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