wtw Multi 9420, Operating Manual, Page: 116 / 132

What to do if... Multi 9420
116
ba75964e04 04/2015
13.2 ISE
Error message OFL
Obviously incorrect
measured values
Error message,
Error (invalid
calibration)
Warning [TpErr]
Warning [ISEErr]
Cause Remedy
– Measuring range exceeded – Dilute the test sample
Cause Remedy
– Electrode not connected – Connect the electrode
– Cable broken – Replace the electrode
Cause Remedy
ISE electrode:
– Moisture in the plug – Dry the plug
– Electrode obsolete – Replace the electrode
– Electrode not suitable for the range
to be measured
– Use a suitable electrode
– Electrode not suitable for the
selected ion
– Use a suitable electrode or
select a suitable ion
– The gas-sensitive electrode NH 500
was calibrated with the NH4 setting
– Select the following settings:
Ion type "ION", Valency "-1"
– Socket damp – Dry the socket
Calibration procedure:
– Wrong sequence of standards for
three point calibration
– Select the correct sequence
– Calibration standards do not have
the correct temperature (max.
±
2 °C
temperature difference)
– Adjust the temperature of the
calibration standards
Cause Remedy
– Temperature difference between
measurement and calibration
greater than 2 K.
– Adjust the temperature of the
test sample
Cause Remedy
– Electrode voltage outside calibrated
range
– Recalibrate