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Troubleshooting and Service Teledyne API T803 CO2/O2 Analyzer Operation Manual
192
11.3.2.4. DISPLAYED FLOW WARNINGS
This warning means that there is inadequate gas flow. There are four conditions
that might cause this:
A leak upstream or downstream of the flow sensor
A flow obstruction upstream or downstream of the flow sensor
Bad Flow Sensor Board
Bad pump
To determine which condition is causing the flow problem, view the sample
pressure and sample flow functions on the front panel display. If the sample
pressure is reading abnormally low, then the cause is likely a flow obstruction
upstream of the flow sensor. First, check the sample filter and make sure it is not
plugged and then systematically check all the other components upstream of the
orifice to ensure that they are not obstructed.
If the sample pressure is reading normal but the sample flow is reading low, then
it is likely that the pump diaphragm is worn or there is an obstruction downstream
of the flow sensor.
11.3.2.5. ACTUAL FLOW DOES NOT MATCH DISPLAYED FLOW
If the actual flow measured does not match the displayed flow, but is within the
limits of 110-130 cm
3
/min, adjust the calibration of the flow measurement as
described in Section 10.3.4.
11.3.2.6. SAMPLE PU
MP
The sample pump should start immediately after the front panel power switch is
turned ON. With the SAMPLE inlet plugged the test function PRES should read
less than 10”-Hg for a pump in good condition. Readings above 10” Hg indicate
that the pump needs rebuilding. If the test function SAMP FL is greater than 10
cm
3
/min there is a leak in the pneumatic lines.
11.4. CALIBRATION PROBLEMS
11.4.1. MISCALIBRATED
There are several symptoms that can be caused by the analyzer being
miscalibrated. Miscalibration is indicated by out-of-range Slopes and Offsets as
displayed through the test functions and is frequently caused by the following:
Bad span gas: This can cause a large error in the slope and a small error in
the offset. Delivered from the factory, the T803’s slope is within ±15% of
nominal. Bad span gas will cause the analyzer to be calibrated to the wrong
value. If in doubt have the span gas checked by and independent lab.
Contaminated zero gas: Excess H2O can cause a positive or negative offset
and will indirectly affect the slope.
Dilution calibrator not set up correctly or is malfunctioning: This will also
cause the slope, but not the zero, to be incorrect. Again the analyzer is being
calibrated to the wrong value.
Too many analyzers on the manifold: This can cause either a slope or offset
error because ambient gas with its pollutants will dilute the zero or span gas.
07276B DCN6418