Unstable Span - Teledyne 9110AH Instruction Manual

TELEDYNE Model 9110AH NO
3. HVPS noisy - see HVPS test procedure. See Section 9.3.8.5.
4. Defective electronic components on preamp board. - use optic test and electric test to check
electronics, optics and observe noise.
5. Contamination of ozone generator and/or reaction cell - This can be wet air or impurities.
This can be detected by high PMT readings with zero air as sample gas. Verify this
condition by turning off the ozone generator using the DIAG mode command and
observing a drop in PMT reading of more than 25 mV. If the ozone generator or reaction
cell is contaminated, disassemble and clean.
6. Broken PMT temperature control circuit. Check PMT TEMP - TEST function.
7. Miss-calibration. Check SLOPES in TEST function.
8. Reaction cell pressure too high. Check RCEL - TEST function.

9.2.6 Unstable Span

Common causes are:
1. Leak in pneumatic system.
2. Light leak - check the sensor module with strong light. Check for missing 0-rings in Sensor
Assembly.
3. Sample lines or sample filter dirty - clean or replace.
4. Plugged sample inlet orifice - clean with methanol and sonic cleaner.
5. Defective HVPS - see HVPS test procedure.
6. Bad or defective PMT detector – replace.
7. Reaction cell temp not stable - observe warning messages, or RCELL TEMP in TEST
functions. Check diagnostic LED in Power Supply Module for normal cycling.
8. Large variations in ambient temperature - observe warning messages, or BOX TEMP in
TEST functions.
9. Pump not maintaining steady vacuum - observe warning messages, or RCEL in TEST
functions.
10. Sample vent line too short, allowing room air to mix with span gas - should be a minimum
of 15" long.
11. Calibration gas source unstable.
Analyzer Operator Manual, 01620, Rev. F
X
9-27