Teledyne API Model 200A NOX Analyzer Instruction Manual, 02246, Rev. G, DCN 5247
3. The value in PMT should come up to 2000 mV ± 500 mV in less than 15 sec.
If the HVPS or the span gain adjust on the preamp card has been changed without doing a
FACTORY CALIBRATE the reading in step 3 may be different than 2000 mV, since the
overall calibration affects ELECTRIC TEST. See Section 9.1.6 for factory calibration
procedure.
4. To turn off ET press EXIT.
If ET is a steady 2000 ± 500 mV, that means the Power Supply Module, Preamp buffer
amplifier, V/F, CPU, and display are all working properly.
9.1.3.3 Optic Test
Optic test turns on a small LED inside the PMT housing which simulates the signal from the
reaction cell. OT tests the entire signal detection subsystem. By observing the level, noise and
drift of this test, correct operation of many sections of the analyzer can be verified.
The implementation of OT involves several changes to the instrument operating conditions. The
M200A does the following when switching to optic test:
1. Saves the current instrument setup as to autorange, indep range, current range and places
the instrument into the 2000 ppb range.
2. Turns off power to the ozone generator to assure there is no interfering light from the
reaction cell.
3. Disables the AUTOZERO circuit.
4. Turns on the OT LED, the PMT reading in TEST functions should be 2000 ± 1000 mV.
To turn on OT, press SETUP-MORE-DIAG, then scroll to OPTIC TEST, then press ENTR.
If the HVPS or the span gain adjust on the preamp card has been changed without doing a
FACTORY CALIBRATE the reading in step 4 may be different than 2000 mV, since the overall
calibration affects OPTIC TEST. See Section 9.1.6 for factory calibration procedure.
9.1.3.4 Ozone Gen Power
This diagnostic manually turns the power off and on to the ozone generator. When the M200A is
powered up from a cold start the ozone generator is not immediately started. This is due to the
fact that humid air may be present in the generator cartridge. Humid air can produce nitric acid
aerosol which can permanently damage parts of the instrument down stream of the generator.
Using this diagnostic, it is possible to turn on the generator before the warmup time has elapsed.
If you turn the power on it will remain on after you exit the diagnostic.
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