Teledyne 300 9.2 A/D - D/A Calibration procedure, Dark current signal adjust procedure

9.2 A/D - D/A Calibration procedure

Due to the stability of modern electronics, this procedure should not have to be performed more than once a year or whenever a major sub-assembly is exchanged or whenever analog output voltage range is changed .

To calibrate the ADC, do the following:

1.Press SETUP-MORE-DIAG.

2.Enter Diagnostic password and press NEXT until D/A CALIBRATION appears in the display and press ENTR.

3.Press ADC to perform the A/D Cal.

4.The M300 display will read "ADJUST ZERO:A/D=xx.x MV.” Put the probe of a voltmeter between TP3(AGND) and TP9(DAC #0) on the top of the V/F card (See Drawing 00514, Appendix C)

5.The value displayed by the voltmeter should be close(+/- 20 mV) to the value on the M300 display. If they are not close then the V/F card has probably been configured improperly.

6.Adjust the Zero pot(R27) on the V/F card until the value on the M300 display matches the value on the voltmeter to within +/- 2 mV. Note that when adjusting R27, the value on the M300 display will change, the value on the voltmeter will remain constant.

7.Press ENTR.

8.The M300 display will now read "ADJUST GAIN:A/D=xx.x MV.”

9.Adjust the Span pot(R31) on the V/F card until the value on the M300 display matches the value on the voltmeter to within +/- 2 mV.

10.Press ENTR.

11.The ADC is now calibrated and the M300 will automatically calibrate all the DAC’s. This process takes only a few seconds

12.Press EXIT 4 times to return to the sample menu.

9.3 Dark current signal adjust procedure

The detector dark current changes little as the detector ages. Therefore this procedure should not need to be performed more than once per year or whenever a major

sub-assembly is changed To calibrate the dark current signal, press SETUP-MORE-DIAG-DARK-CALand the analyzer will automatically do the following:

1.Disconnect the detector output from the processing electronics

2.Wait 2 minutes for electronics to stabilize at the dark value

3.Average CO MEAS and CO REF reading for 1 minute

4.Reconnect the detector output to the processing electronics to the processing electronics.

The average CO MEAS and CO REF dark reading are stored as offsets which are subtracted from all future CO detector readings.

P/N 02163G1 Teledyne API Model 300 CO Analyzer Instruction Manual - Page 79