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Teledyne 2000A-EU - General purpose thermal conductivity analyzer User Manual

Page 36

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Teledyne Analytical Instruments

3 Installation

Model 2000A-EU

3-14

When installing pressure regulators on supply cylinders, crack the

cylinder valves so that gas is flowing during installation. This will elimi-
nate the most common cause of standardization-gas contamination: air
trapped during assembly diffusing back into the cylinder. This procedure is
particularly important in applications where impurity content of 1 to 2 % is
the range of interest.

Note: If you have the –V option, The above pressure and flow

values apply instead to the vacuum at the VENT connector,
described below, with minus signs before the pressure
readings.

3.4.3 VENT Exhaust

There are two separate VENT fittings—one for the sample gas and

one for the reference gas

.

Use 6 mm tubing for both sample and reference

vents to minimize back pressure from restricted flow.

Exhaust connections must be consistent with the hazard level of the

constituent gases. Check local, state, and federal laws, and ensure that the
exhaust stream vents to an appropriately controlled area if required. If not
vented to the same area, both VENT lines must vent to areas with equal
ambient pressures, and pressures must vary no more than the normal
barometric changes.

Install VENT lines such that water and dirt cannot accumulate in

them.

Note: If your 2000A has the –V option, see Note at end of

Pressure

and Flow Rate Regulation, above, for gas flow considerations.

3.4.4 SAMPLE Gas

In the standard model, sample and calibration gases are introduced

through the

SAMPLE

fitting. The gases must be Tee'd into the Sample inlet

with appropriate valves.

The gas pressure in should be well regulated. (See section 3.4.1.) The

sample line pressure regulator should be installed as close to the sample
line as possible to minimize sample line lag time.

If greater flow is required for improved response time, install a bypass

in the sampling system upstream of the analyzer input.