Teledyne 6400EH - Sulfur Dioxide Analyzer - Manual (Page 63)

UV Fluorescence SO2 Analyzer Troubleshooting
Teledyne Analytical Instruments 51
9. Set the HVPS fine adjustment switch to its maximum setting (F).
10. Turn the gain adjustment potentiometer clockwise to its
maximum setting.
11. Set the front panel display to show
STABIL
(see Section 6.2.1 of
the 6400E Manual)
12. Feed span gas into the analyzer.
13. Wait until the
STABIL
value is below 0.5 ppm,
Note: Use a span gas equal to 80% of the reporting range.
Example: for a reporting range of 200 ppm, use a span gas
of 160 ppm.
14. Scroll to the
OFFSET function and record the value.
15. Scroll to the
NORM PMT value.
Note: Do not overload the PMT by accidentally setting both
adjustment switches to their maximum setting.
This can cause permanent damage to the PMT.
16. Determine the target
NORM PMT value according to the
following formulas.
 If the reporting range is set for ≤ 500 ppm (the instrument
will be using the 500 ppm physical range):
Target
NORM PMT = (8 x span gas concentration) + OFFSET
 If the reporting range is set for ≥ 2,001 ppb (the instrument
will be using the 5,000 ppm physical range):
Target
NORM PMT = (0.8 x span gas concentration) + OFFSET
EXAMPLE
: If the
OFFSET
is 33 mV, the Reporting Range is
1000 ppm, the span gas should be 800 PPM SO
2
and the
calculation would be:
Target
NORM PMT = (0.8 x 800) + 33 mV
Target
NORM PMT = 640 + 33 mV
Target
NORM PMT = 673 mV
17. Set the HVPS coarse adjustment switch to the lowest setting that
will give you more than the target
NORM PMT
signal from Step
16.