Hach Lange SensION+ MM 378 User Manual page 18

Troubleshooting
Refer to the following table for common problem messages or
symptoms, possible causes and corrective actions.
Table 1 Calibration warnings and errors
Error/Warning
Calibration out of Measured value out of range.
range Calibrate again. Connect a new probe.
Unknown buffer Calibrate again.
Examine the probe: Clean the probe (refer to
Same buffer /
probe on page 16 for more information); make sure that
standard. Re-
there are no air bubbles in the membrane. Shake the
calibrate
probe like a thermometer; connect a different probe to
find if the problem is with the probe or the meter.
Examine the buffer solution: Make sure that the buffer
used matches the buffer specified in configuration; make
sure of the temperature specification in configuration; use
a new buffer solution.
Unstable Calibrate again.
measurement
Examine the probe: Clean the probe (refer to
Time > 100 s (pH, probe on page 16 for more information); make sure that
EC and DO there are no air bubbles in the membrane. Shake the
calibrations) probe like a thermometer; connect a different probe to
find if the problem is with the probe or the meter.
Time > 240 s (ISE
calibrations) Make sure that the membrane and the diaphragm are
properly immersed in the sample.
Temperature Adjust the calibration solutions to the same temperature.
difference > 3.0 ºC
Examine the temperature sensor.
Temperature out of Examine the temperature sensor.
range Connect a new probe.
18 English
Solution
Clean the
Clean the
Table 1 Calibration warnings and errors (continued)
Error/Warning
Outside allowable Offset or Slope outside the range.
range Examine the buffer solution: Make sure that the buffer
used matches the buffer specified in configuration; make
sure of the temperature specification in configuration; use
a new buffer solution.
Examine the probe: Clean the probe (refer to
probe on page 16 for more information); make sure that
there are no air bubbles in the membrane. Shake the
probe like a thermometer; connect a different probe to
find if the problem is with the probe or the meter.
Signal too low / high DO probe error.
(DO calibrations) Examine the probe. Connect a different probe to make
sure that if problem is with probe or meter.
Use a new standard solution.
Cell constant over Insert the probe into the appropriate standard and re-
limits (EC read.
calibrations) Examine the probe: Clean the probe (refer to
probe on page 16 for more information); make sure that
Cell constant
there are no air bubbles in the membrane. Shake the
deviation error (EC
probe like a thermometer; connect a different probe to
calibrations)
find if the problem is with the probe or the meter.
Not calibrated There are no calibration data stored in the instrument.
Perform calibration.
Solution
Clean the
Clean the