Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
9-22
10. Adjust S2, the HVPS coarse adjustment, on the preamp board to the setting that produces a
signal that is closest to 640 mV. Adjust S1, the HVPS fine adjustment, to the setting that
produces a signal that is closest to 640 mV. Use R19 to trim the reading to 640 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 10 minutes. The reading is stable when the
STABIL – TEST function drops to 2.0 or less. Then do a span calibration by CAL-SPAN-
ENTR. After the span is completed, do the span quality check procedure in Table 7-11. This
procedure is extremely important to assure that the instrument will operate with optimum
noise, linearity, and dynamic range.
Electric Test (ET) Procedure:
1. Any time the gain of the PMT buffer amplifier circuit (R19) is changed, that will change the
ET reading. Since the gain was adjusted in the above procedure do the following to re-adjust
the ET signal.
2. To re-adjust ET press SETUP-MORE-DIAG, then scroll to ELEC TEST and press ENTR.
3. Scroll the TEST functions until PMT is displayed.
4. Adjust R27 until 2000 mV 50 is displayed.
5. Press EXIT to return to SAMPLE mode.
Optic Test (OT) Procedure:
1. Any time the PMT buffer amplifier circuit (R19) gain and/or the PMT high voltage setting is
changed the OT reading will also change. The Factory Cal procedure can change both of
these values.
2. To re-adjust OT press SETUP-MORE-DIAG, then scroll to OPTIC TEST and press ENTR.
3. Scroll the TEST functions until PMT is displayed.
4. Adjust R25 until 100 mV 5 is displayed.
5. Press EXIT to return to SAMPLE mode.
If this procedure does not produce an instrument that will properly span please contact your local
distributor or the Teledyne API factory. Teledyne API's phone number is on the front page of
this manual.