Teledyne 316RA / RB / RAD / RBD - Oxygen analyzers - Manual (Page 10)

TELEDYNE ANALYTICAL INSTRUMENTS
6
Model 316RA/RB/RAD/RBD Trace Oxygen Analyzer
Pressure Reduction or Regulation
TAI recommends that sample pressure be reduced at the sample point
to between 5 and 50 psig (10 psig nominal). If the magnitude of the sample
pressure does not exceed 100 psig and is reasonably stable, a simple
throttle valve is sufficient. However, if the pressure exceeds 100 psig or
oscillates over a wide range, use a metallic diaphragm pressure regulator.
IMPORTANT: If using a certified composition span gas, equip the supply
cylinder with a metallic diaphragm regulator.
Using a regulator with an organic diaphragm may allow oxygen to
dissolve into the sample or span gas, and will affect readings.
Zero Or Near Zero Pressure Sampling
In applications where the sample pressure is either zero or near zero,
TAI recommends placing a sample pump downstream from the analyzer in
vacuum service to draw sample through the analyzer from the sample
point. TAI rearranges the integral sampling path (specified at the time of
purchase) so that the throttle valve is downstream of the cell. This prevents
the cell from experiencing a partial pressure environment and prevents
diffusion contamination.
Vent Connection
The Series 316 Oxygen Analyzer should vent directly to the atmo-
sphere. If venting directly is not possible, install the vent line under the
following conditions:
1. The vent line must be constructed of ¼ " tubing (or
equivalent), so that no back-pressure resulting from
restricted flow occurs.
2. The vent line must end in an area that experiences no more
than normal barometric pressure changes.
3. The vent line must be installed so that water and dirt cannot
accumulate in it.
Electrical Connections
Make all customer wiring connections at the terminal strips, located
on the motherboard. For the power, output signal, and alarm relay wiring
locations, see the Interconnection Diagram (dwg. A-33140).