Teledyne API Model 200AH NOX Analyzer Instruction Manual, 06492, Rev. G2
7-9
Table 7-8: Manual Span Check Procedure - Z/S Valves
Step Number Action Comment
1. Press CALS The M200AH enters the span calibrate mode and switches the
Z/S valves to admit NO span gas.
2. Select LO or HI
range If AutoRange is enabled you will be prompted for which
range to calibrate. Select the LO or HI range, then press
ENTR.
3. Wait 10 min Wait for reading to stabilize at span value.
4. Press SPAN If you change your mind after pressing SPAN, you can still
press EXIT here without spanning the instrument.
5. Press ENTR Pressing ENTR actually changes the calculation equations
and causes the instrument to read the expected NO and NOX
span concentrations.
6. Press EXIT The Zero/Span valves are switched back to admit gas through
the sample port and instrument returns to SAMPLE mode.
Immediately after calibration, data is not added to the DAS
averages.
7.4. Dynamic Zero/Span Calibration Using AutoCal
The M200AH can be automatically calibrated periodically using the Zero/Span Valve Option
and features in the AUTOCAL menu. The Dynamic Zero/Span feature can be enabled when an
AutoCal Sequence is set up. Refer to Section 6.2 for information.
With the Dynamic AutoCal in operation, the M200AH is being continuously re-calibrated. We
recommend that the quality of the calibrations be carefully monitored to assure that the
instrument is performing correctly. Subtle fault conditions can sometimes be masked by
continuous re-calibration.