IM 12D08N05-01E
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<8. TROUBLESHOOTING>
8.3 Predictive maintenance
SC450G has a unique prediction feature. Calibration, data is stored in software data
logbooks. This data is then used to calculate a prediction for maintenance purposes.
8.4 Prediction of cleaning needed
The date when the next maintenance is needed is calculated from on-line polarization
checks. The trend of polarization measurements on the sensor is used to calculate when to
tell the user when to clean the sensor.
8.5 Poor calibration technique
When the calibration data is not consistent this fact is used as a diagnostic tool. The
significance of this error message is to require the user to improve his calibration
technique. Typical causes for this error are attempting to calibrate dirty sensors, calibration
solution contamination and poor operator technique.
8.6 Error displays and actions
All errors are shown in the “Main Display” screen, however, the SC450G makes a
distinction between diagnostic findings. The error messages may be set to OFF, WARN
or FAIL. For process conditions where a particular diagnostic may not be appropriate, the
setting OFF is used. FAIL gives a display indication only of that the system has a problem
and inhibits the relay control action, and can be set to trigger the “Burn” function. “Burn-up
or Burn-down” drives the mA output signal to 21 mA or 3.6 mA respectively.
