Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
9-16
9.1.3.2. Electric Test
This function injects a constant voltage between the preamplifier and the buffer amplifier on the
preamp board. Electric test checks part of the preamp, the V/F and computer for proper
functioning. The result of electric test should be a smooth quiet signal as shown by constant
values for the NO, NOX concentrations, the NO2 concentration should be near zero. Likewise the
analog outputs should produce a smooth quiet trace on a strip chart.
Procedure:
1. Scroll the TEST function to PMT.
2. Press SETUP-MORE-DIAG, then scroll to ELECT TEST by pressing the NEXT button.
When ET appears, press ENTR to turn it on.
3. The value in PMT should come up to 2000 mV 200 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 CALIBRATION, 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, 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 instrument operating conditions. The
M200AH does the following when switching to optic test:
1. Save the current instrument setup as to AutoRange, indep range, current range and place the
instrument into the 500 ppm range.
2. Turn off power to the ozone generator to assure there is no interfering light from the reaction
cell.
3. Turns off the AutoZero valve switching.
4. Turn on the OT LED, the PMT reading in TEST functions should be 100 20 mV.
If the HVPS or the span gain adjust on the preamp card has been changed without doing a
FACTORY CALIBRATION, the reading in Step 3 may be different than 100 mV, since the
overall calibration affects OPTIC TEST. See Section 9.1.6 for factory calibration procedure.