What to do when you receive an out of measuring range for DIS message on the analyzer.
Typical Result:
- Most Common- Unexpected process event caused overdosing of chemical. Considering interlocking Kuntze flow switch/external controller stop into chemical control logic.
- Common- Sensor was not manually cleaned before calibration. Manually clean sensor and perform a new calibration.
- Least Common- Sensor expired and needs replaced.
Note: Sensor life expectancy is water quality and application specific. Best practice suggests annual replacement of process dependent sensors.
The measured value exceeds the selected measuring range, but the input can still cope with the signal. "Check DIS 1 input" will soon appear.
Suggestion:
- Switch to a higher measuring range (Main menu > In/Out > Analog > DIS)
- Review preventative methods to reduce the change for over-dosing chemicals.
- i.e. integrating a flow switch/controller stop into your control logic.
- Check if the calibration values (slope/zeropoint) are in a reasonable range.
Helpful article: Check measuring input - DIS