Teledyne API Model 200AU NOX Analyzer Instruction Manual, 02293, Rev. F
9-16
Table 9-4: Diagnostic Mode - Signal I/O (Continued)
No. Signal Control Description
37 DAC_CHAN_2 NO Output of NO2 channel in mV.
38 DAC_CHAN_3 NO Test Channel output.
39 NOX_CONC YES NOx DAC programming voltage. The following 4
signals can be set to output specific voltages to each
DAC. Use in conjunction with ANALOG OUTPUT
test to check each DAC output channel. The value
keyed in should appear on the appropriate analog
output channel. This value overrides data being
written from the analyzer. Value reverts to instrument
output when function is exited.
40 NO_CONC YES NO DAC programming voltage. See above for
description.
41 NO2_CONC YES NO2 DAC programming voltage. See above for
description.
42 TEST_OUTPUT YES TEST channel programming voltage. See above for
description.
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 ± 500 mV in less than 15 sec.
If the HVPS or the span gain adjust on the preamp card has been changed without doing the
FACTORY CALIBRATION procedure, 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.