Teledyne 200A, Instruction Manual, Page: 166 / 220

Teledyne API Model 200A NO
X
Analyzer Instruction Manual, 02246, Rev. F1
9. Calculate the expected NORM PMT mV reading.
For ranges up to 2000 ppb, multiply the expected span value by 2 to get the mV reading.
For ranges 2001 to 20000 ppb, multiply the expected span value by .2 to get the mV reading.
In this example the expected span gas concentration is 400 ppb and therefore the expected
voltage is 800 mV. As an alternate method, the voltage can be determined from the graph in
Figure 9-1. On the Y-axis find the calibration concentration in ppb, then determine the
expected voltage from the X-axis.
10. Adjust S2, the HVPS coarse adjustment, on the preamp board to the setting that produces
a signal that is closest to 800 mV. Adjust S1, the HVPS fine adjustment, to the setting that
produces a signal that is closest to 800 mV. Use R19 to trim the reading to 800 ± 50 mV. The
readings will periodically go to zero as the AutoZero circuit operates, ignore the zero
readings.
11. Allow the instrument to sample span gas for 30 minutes. Then do a span calibration by
CAL-SPAN-ENTR. After the span is completed, do the span quality check procedure in
Table 7-19. This procedure is extremely important to assure that the instrument will operate
with optimum noise, linearity, and dynamic range.
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