Teledyne GFC 7001E Carbon Monoxide Alarm User Manual


 
Troubleshooting & Repair Model GFC7001E Carbon Dioxide Analyzer
Teledyne Analytical Instruments 278
13.2. 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 12.3.4. If this test shows the flow to be correct, check the pressure sensors
as described in Section 13.5.6.6.
The GFC 7001E/EM 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 iDAS.
With the O
2
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
12.3.4 is essential.
The flow diagrams found in a variety of locations within this manual depicting the GFC 7001E/EM in its standard
configuration and with options installed can help in trouble-shooting flow problems. For your convenience they
are collected here.
13.2.1. GFC 7001E/EM INTERNAL GAS FLOW DIAGRAMS
Figure 13-6: GFC 7001E/EM – Basic Internal Gas Flow