VWR International MU 6100 H, Instruction Manual

Page: 79 / 96

MU 6100 H What to do if...
ba77077e02 09/2014
79
14 What to do if...
14.1 pH/ORP
Error message
OFL, UFL
The measured value is outside the measuring range.
Error message,
Error
More information and instructions on cleaning and exchange of
sensors are given in the documentation of your sensor.
Cause Remedy
Electrode:
– Air bubble in front of the junction – Remove air bubble
– Air in the junction – Extract air or moisten junction
– Cable broken – Replace the electrode
– Gel electrolyte dried out – Replace the electrode
– The measured value is outside
the measuring range of the meter
– Use a suitable electrode
Cause Remedy
Electrode:
– The values determined for zero
point and slope of the electrode
are outside the allowed limits.
– Recalibrate
– Junction contaminated – Clean the junction
– Electrode broken – Replace the electrode
Buffer solutions:
– Incorrect buffer solutions – Change calibration procedure
– Buffer solutions too old – Use only once.
Note the shelf life
– Buffer solutions depleted – Change solutions