Hach NO3D sc User Manual

34Troubleshooting6.3 Troubleshooting6.3.1 Troubleshooting during operationSymptom Possible cause Corrective actionsIncorrect measurementvaluesCalibration too old; calibration was not suitable forthe particular case; big change in the waste watermatrixCarry out suitable calibrationSee 4.6 Calibration on page 22Strongly contaminated membranes and/orreference electrodeClean the sensor cartridge using a brushand/or rinse the sensor cartridge with cleanwater (without cleaning agents), and wipe thesensor cartridge carefully with a soft, cleancloth.Clean all components (membranes/referenceelectrode/temperature sensor).Install cleaning unitIncrease cleaning intervalSensor membrane damaged Check sensor installation/replace sensorcartridgeReference element damaged Check sensor installation/replace sensorcartridgeNO3 mV RANGE! (Nitrate mV value is out ofmeasuring range) Replace sensor cartridgeCL- mV RANGE! (Chloride mV value is out ofmeasuring range) Replace sensor cartridgepHD RANGE! (pHD reference value is out ofrange) Replace sensor cartridgeTEMPERATURE (temperature value is out ofrange)Replace sensor cartridge/check waste watertemperatureCARTRIDGE OLD (cartridge more than 1 yearold) Replace sensor cartridgeDampness at the contacts of the sensor cartridgeDry the contacts with a cloth or some paper.Check the opaque gasket for damage andthe correct position.Screw the locking ring on.Note: Use the cap of the storage container asa tool/screwing aid for the locking ring(Figure 9 on page 15).