5.Pressing SETUP-MORE-DIAG-ENTR-NEXT, and select ANALOG OUTPUT. Verify the quality of ADC/DAC calibration by measuring the test channel output voltage. The signal consists of a scrolling 0%, 20%, 40%, 60%, 80%, 100% of the analog output value. The scrolling may be stopped by pressing the key underneath the % display to hold that value and will display within the square bracket ( [%] ). Press key once again to continue scrolling or press EXIT to terminate. The exact voltage values depend on the DIP switch settings on the analog output buffer amplifiers.
To calibrate the 4-20 mA current output option, do the following:
Verify ± 5 volt output DIP switch setting (refer to Figure 10-2)for 4-20 ma option before proceeding following procedure, since the input voltage of the 4-20 mA converter hardware is configured for 0-5 volt range.
1.Connect the 300 - 1000 ohm resistor to one of the 4-20 mA recorder output terminal 1 or 2 (refer to Figure 2-2). Connect in series the DC current meter between the resistor and other terminal of the recorder output with proper polarity.
2.Press SETUP-MORE-DIAG-ENTR and scroll down to the D/A CALIBRATION diagnostic mode, press ENTR to start the procedure. Press CFG and scroll by pressing NEXT to select desired current output channel, press SET-CURR-ENTR to define current output channel.
3.Press CAL to start the calibration. The M100AH display will read
"x)CONC_OUT_X,CURR,ZERO", where X is the output channel number. Press the up/down buttons on the front panel until the current meter displays 4.0 mA (± 0.1mA). When the current meter shows a stable 4.0 ± 0.1 mA, press ENTR.
4.The M100AH display will now show "x)CONC_OUT_X,CURR,GAIN". As before, press the up/down buttons on the M100AH front panel until the current meter reads 20.0 ± 0.1 mA.
5.Repeat step 1 through 4 for additional current channel output calibration. Each current channel must be calibrated separately. When completed press EXIT to return to upper level menus.
6.Verify that the analog output is correct by performing SETUP-MORE-DIAG-ANALOG OUTPUT. The current meter should read 4, 7.2, 10.4, 13.6, 16.8, and 20 mA accordingly. See Section 10.3.3.4 for additional current output measurement methods.
10.3.2.2 Changing Output Voltage Ranges
If you are using analog voltage output, several different output voltage ranges can be selected by DIP switch setting on the V/F board. See Figure 9-3for the DIP switch settings. If you change the analog output voltage range, then you must reset the power of the instrument and do a ADC/DAC calibration per Section 10.3.2.1.
