wtw Multi 9310 - Troubleshooting Guide; pH Measurement Issues

What to do if... Multi 9310
88 ba75937e03 12/2011
14 What to do if...
14.1 pH
Error message
OFL, UFL
Error message,
Error
More information and instructions on cleaning and exchange of
sensors are given in the documentation of your sensor.
Cause Remedy
IDS pH sensor:
– Measured value outside the
measuring range
– Use suitable IDS pH sensor
– Air bubble in front of the junction – Remove air bubble
– Air in the junction – Extract air or moisten junction
– Cable broken – Exchange IDS pH sensor
– Gel electrolyte dried out – Exchange IDS pH sensor
Cause Remedy
IDS pH sensor:
– The values determined for zero
point and slope of the IDS pH
sensor are outside the allowed
limits.
– Recalibrate
– Junction contaminated – Clean junction
– IDS pH sensor broken – Exchange IDS pH sensor
Buffer solutions:
– The used buffer solutions do not
agree with the set buffer set
– Set different buffer set
or
– Use different buffer solutions
– Buffer solutions too old – Use only once.
Note the shelf life
– Buffer solutions depleted – Change solutions