Low Flow; High Flow; Actual Flow Does Not Match Displayed Flow; Sample Pump - Teledyne T400 User Manual

5.7.5.2 LOW FLOW

1. Check if the pump diaphragm is in good condition. If not, rebuild the pump (see
2. Check for leaks as described in Section 5.6.3. Repair the leaking fitting, line or
3. Check for the sample filter and the orifice filter for dirt. Replace filters (see 5.6.1).
4. Check for partially plugged pneumatic lines, or valves. Clean or replace them.
5. Check for plugged or dirty critical flow orifices. Replace them.
6. If an IZS option is installed in the instrument, press CALZ and CALS. If the flow

5.7.5.3 HIGH FLOW

The most common cause of high flow is a leak in the sample flow control assembly or
between there and the pump. If no leaks or loose connections are found in the fittings or
the gas line between the orifice and the pump, replace the critical flow orifice (s) inside
the sample flow control assembly.

5.7.5.4 ACTUAL FLOW DOES NOT MATCH DISPLAYED FLOW

If the actual flow measured does not match the displayed flow, but is within the limits of
720-880 cm
Section 5.6.6.

5.7.5.5 SAMPLE PUMP

The sample pump should start immediately after the front panel power switch is turned
ON. With the Sample Inlet plugged, the Pressure reading should be about 10 in-Hg for a
pump that is in good condition. The pump needs rebuilding if the reading is above 10 in-
Hg. If the Sample Flow reading is greater than 10 cm
pneumatic lines.
5.7.6 C
ALIBRATION

5.7.6.1 MISCALIBRATED

There are several symptoms that can be caused by the analyzer being miscalibrated. This
condition is indicated by out of range Slopes and Offsets as displayed through the test
functions and is frequently caused by the following:
Contaminated span gas. This can cause a large error in the slope and a small error in
•
the offset. Span gas contaminated with a major interferent such as Mercury Vapor, will
cause the analyzer to be calibrated to the wrong value. Also could be caused if the span
gas concentration entered into the analyzer during the calibration procedure is not the
precise concentration value of the gas used.
• Contaminated zero gas. This can cause either a positive or negative offset and will
indirectly affect the slope. If contaminated with O
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.
122
Section 5.6.2). Check the Spare Parts List for information on pump rebuild kits.
valve and re-check.
increases then suspect a bad sample/cal valve.
3 /min, adjust the calibration of the flow measurement as described in
P
ROBLEMS
Teledyne API – Model T400 O
3 /min there is a leak in the
, it will cause a positive offset.
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Analyzer 083730400A DCN8130
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