Teledyne 6400A Instruction Manual page 134

TAI Model 6400A SO
Table 9-4: Diagnostic Mode - Signal I/O (Continued)
No Signal
34 DAC_CHAN_2
35 DAC_CHAN_3
36 UVLAMP_SIGNAL
37 CONC_OUT_1
38 CONC_OUT_2
39 TEST_OUTPUT
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 SO
concentration. Likewise the analog outputs should produce a smooth quiet trace on a strip chart
(analog output range is set to 2000ppb and auto-ranging is disabled).
Procedure:
1. Scroll the TEST function to PMT.
2. Press SETUP-MORE-DIAG, 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 ± 1000mV 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 ± 1000 mV, that means the Power Supply Module, preamp buffer amplifier,
V/F, CPU, and display are all working properly.
Analyzer Operator Manual, 02164, Rev. G
2
Control Description
NO Output of spare (DAC2) channel in mV.
NO Test Channel (DAC3) output.
NO Current UV lamp signal voltage in mV. Same as UV
LAMP in TEST menu. Bi-polar, typically 0-5000 mV
range. A constant value of 5000 mV indicates
offscale.
YES DAC0 (SO
YES DAC1 (SO
YES DAC3 (TEST CHANNEL) analog output in mV
9-16
/RANGE1) analog output in mV
2
/RANGE2) analog output in mV
2
2