Teledyne 6200E - Sulfides Analyzer - Manual (Page 263)

Model 6200E Instruction Manual TROUBLESHOOTING & REPAIR
M6200E Rev: A1 263
4. Locate the Preamp board (Figure 3-9).
5. Locate the Following Components On the Preamp board (Figure 11-4):
• HVPS coarse adjustment switch (Range 0-9, then A-F)
• HVPS fine adjustment switch (Range 0-9, then A-F)
• Gain adjustment potentiometer (Full scale is 10 turns).
Figure 11-4: Pre-Amplifier Board Layout
6. Turn the gain adjustment potentiometer 12 turns clockwise to its maximum setting.
7. While feeding 400 ppb H
2
S (or 80% range value) to the analyzer and waiting until the STABIL
value is below 0.5 ppb, look at the front panel and scroll to the NORM PMT value. This value
should always be two times the span gas concentration in ppb. With 400 ppb H
2
S, the NORM
PMT should show 800 mV on a properly calibrated analyzer.
8. Set the HVPS coarse adjustment to its minimum setting (0). Set the HVPS fine adjustment
switch to its maximum setting (F).
9. Set the HVPS coarse adjustment switch to the lowest setting that will give you more than 800
mV NORM PMT signal. The coarse adjustment typically increments the NORM PMT signal in
100-300 mV steps.
10. Adjust the HVPS fine adjustment such that the NORM PMT value is just above 800 mV. It may
be necessary to go back and forth between coarse and fine adjustments if the proper value is
at the threshold of the min/max coarse setting.