Teledyne GFC-7001T - Trace CO Analyzer - Manual (Page 261)

Troubleshooting and ServiceTeledyne API – Model T300/T300M CO Analyzer
Teledyne Analytical Instruments 261
12.2. GAS FLOW PROBLEMS
When troubleshooting flow problems, it is a good idea to first confirm that the actual
flow and not the analyzer’s flow sensor and software are in error, or the flow meter is in
error. Use an independent flow meter to perform a flow check as described in Section
11.3.3. If this test shows the flow to be correct, check the pressure sensors as described
in Section 12.5.7.6.
The GFC7001T/GFC7001TM has one main gas flow path. With the IZS or zero/span
valve option installed, there are several subsidiary paths but none of those are displayed
on the front panel or stored by the DAS.
With the O2 sensor option installed, third gas flow controlled with a critical flow orifice
is added, but this flow is not measured or reported.
In general, flow problems can be divided into three categories:
1. Flow is too high
2. Flow is greater than zero, but is too low, and/or unstable
3. Flow is zero (no flow)
When troubleshooting flow problems, it is crucial to confirm the actual flow rate without
relying on the analyzer’s flow display. The use of an independent, external flow meter
to perform a flow check as described in Section 11.3.3 is essential.
The flow diagrams found in a variety of locations within this manual depicting the
GFC7001T/GFC7001TM in its standard configuration and with options installed can
help in trouble-shooting flow problems. For your convenience they are collected here.