wtw ProfiLine pH 197 Bedienungsanleitungen Seite 45

Trouble Shooting
E3 E3
Slope or asymmetry
not within the
admissible ranges
(Slope:
-50 ... -62 mV/pH;
Asymmetry:
-30 ... +30 mV)
No message
Electrode voltage
not stable
No message
Wrong measured
values
Instrument doesn't
react upon key
operation
LoBat
to to
pH electrode:
•
pH electrode too old
•
Diaphragm contaminated
•
Membrane contaminated
•
Humidity in the plug
•
Old electrolyte solution
Instrument:
•
Wrong calibration
procedure
•
Wrong solution temperature
(without temp. sensor only)
•
Humidity in the socket
Buffer solution:
•
Improper buffer solutions
•
Spoiled buffer solutions
pH electrode:
•
Diaphragm contaminated
•
Membrane contaminated
Sample solution:
•
ph-value not stable
•
Temperature not stable
pH electrode +measuring
solution:
•
Too low conductivity
•
High temperature
Organic liquids
pH electrode:
•
Improper pH electrode
•
Temperature difference
between calibration and
measuring solution too high
•
Interference voltages
•
Improper measuring
procedure
Undefined operation
condition of the processor e.g.
after non-admissible EMC
admission
Rechargeable batteries nearly
discharged.
Timeout of the serial interface Check connected instrument
pH electrode:
Replace pH electrode
Clean diaphragm
Clean membrane
Dry plug
Exchange electrolyte solution
Instrument:
Select right procedure
Set right temperature
Dry socket
Buffer solution:
Select solutions corresp. to the
calibration procedure
Use solutions once only
pH electrode:
Clean diaphragm
Clean membrane
Sample solution:
Possibly measure without air
contact
Possibly temper
Use suitable pH electrode
Use suitable pH electrode
Use suitable pH electrode
pH electrode:
Select suitable pH electrode
Temper buffer or measuring
solutions
Do not connect grounded PC
or printer if measuring solution
is grounded
Attend to special procedures
Processor reset:
Press key RCL and switch on
the instrument
Charge.
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