Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
9-30
7. Ozone concentration too low:
A. Wet air in generator - need to disassemble, clean, dry.
B. Electrical short circuit.
C. Transformer partial failure.
8. Sample inlet vent line too short - should be at least 15".
9. Sample exhaust not properly vented, creating a backpressure at the sample inlet port of the
instrument. See Figure 2-4 for venting recommendations.
9.2.11. Slow Response
1. Contaminated or dirty sample delivery pneumatics:
A. Dirty/plugged sample filter or sample lines.
B. Dirty reaction cell.
2. Sample inlet line too long.
3. Wrong materials in contact with sample - use glass, stainless steel or Teflon.
4. Sample vent line located too far from instrument sample inlet. - Locate sample inlet vent as
close as possible to analyzer.
5. Insufficient time allowed for purging of lines upstream of analyzer.
6. Leaking NO/NOX or AutoZero valve. The leak can either be external or cross-port.
7. Insufficient time allowed for calibration cal gas source to become stable.
8. Converter temperature too low.
9.2.12. Analog Output Doesn't Agree With Display Concentration
1. V/F board DAC's out of calibration. Do DAC calibration and Factory Calibration.
2. Analog outputs electrically loaded down causing voltage to sag. Could be due to input
impedance to chart recorder or data logger being too low or improper grounding. The
Recorder and DAS outputs do not have separate output drivers, the problem could be the
combined load of both could be too high.