Teledyne 6200A Manual page 148

TAI Model 6200A SO
Table 9-1: Test Functions (Continued)
Test Function Factory Set-Up
PMT 0 - 5000 mV
UV LAMP 1000 - 4800 mV
(table continued)
Analyzer Operator Manual, 02164, Rev. G
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Comment
This is the instantaneous output of the PMT.
The PMT voltage values will be relatively constant when:
Electric test - variation in the 2000 mV signal observed will be
noise of the V/F board and preamp noise. See Section 9.1.3.2.
Optic test - variation in the 2000 mV signal will be PMT dark
current, preamp, HVPS plus item 1 above. See Section 9.1.3.3.
Sampling zero gas.
Sampling stable SO
When sampling zero gas the PMT reading should be less than
450mV and relatively constant.
High or noisy readings could be due to:
Pneumatic leak.
Excessive background light which is caused by a possible aging
UV filter.
Low UV lamp output.
PMT recently exposed to room light. It takes 24-48 hours for
the PMT to adapt to dim light.
Light leak in reaction cell.
Reaction cell contaminated.
This is the instantaneous reading of the UV lamp intensity.
Typical UV lamp intensity is between 2000 mV and 4000 mV.
See Section 9.4.2 for how to peak the UV lamp output.
Intensity lower than 1000 mV will cause WARNING and
below 600mV will cause to display XXXXX.X.
Low UV lamp intensity could be due to:
Aging UV lamp.
UV lamp position out of alignment.
Faulty lamp transformer.
Aging or faulty UV detector.
Dirty optical components.
9-5
span gas.
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