REV 0, June 2005 Page 189
Operation Manual SUPREMA
7. Maintenance and Service
Person 1:
• The current measurement value of the measure point to be calibrated is shown in the
“Sig:” field. After the test gas has been supplied for a sufficient period of time – all 5 digits
of the bar display are filled black – confirm the value by actuating the control field “[Store]”.
The value is shown now in the “CAL-SPAN/mV” field.
• Conclude the calibration of the selected input by actuating the control field “[End]”.
Note: Signals UA above 600 mV are not valid for the zero point calibration.
Signals UA below 600 mV are not valid for the span calibration.
• A dialog menu will appear: “Preliminary calibration? NO=<ESC>, YES=<ENTER>”.
Terminate the calibration by actuating the “ESC” key. Pressing the “ENTER” key deletes
the measurement values of earlier calibrations stored in the calibration menu and in the
“Diagnosis/Logbook” (should be used only after replacement of a sensor).
• In the start calibration menu, select the next input and repeat the procedure described
here.
Person 2:
• After being informed by person 1 that the sensitivity calibration has been completed
successfully, shut off the test gas supply and start zero gas supply at next input to be
calibrated.
Note: If the preadjustment was correct, the ACTUAL VALUES for the zero point
will be approximately in the range of 350 mV to 450 mV.
The signal voltage shown is calculated according to the formula:
Signal = C / 100
*
1600 mV + 400 mV
(for sensors with a linear output signal),
where C is the concentration of the test gas as a % of the measuring range.
The tolerance is approximately equal to the signal value in mV ± 100 mV.
Attention: If the signal voltage exceeds a value of 2000 mV during the test gas
supply the calibration is invalid. In no case may the calibration value be accepted.
Instead, terminate the calibration by actuating the control field “[Cancel]”. Then
check the choice of test gas concentration and make sure that it is being supplied
correctly. It may be necessary to check and correct the preadjustment of the
measure point on the MAI module.
7.1.2 Active Sensors
For active sensor (sensors with an output of 4 ... 20 mA), the calibration is to be performed
directly on the sensor in accordance with the relevant operating and maintenance instructions.
As default values, the SUPREMA system interprets an input current of 4 mA as 0% of the
measuring range and an input current of 20 mA as 100 % of the measuring range.
Attention: In the case of sensors which do not transmit a maintenance level during
calibration, we recommend that the measure point be locked during the preliminary
calibration in the “Setup/Measure point” menu.
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