Xylem wtw F 800 DIN, Operating Manual

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ba15358d04 12/2021
What to do if ... F 800
Calibration line of a fluoride sensitive electrode
What to do if ...
Measured value
unstable
Slope too low
1 0.1 10 100 1000
~58 mV
mg/l
10
10
10
10
mol/l F
10
Meßkettenspannung Electromotive force
10-fache Konzentrationsänderung 10-fold concentration change
-5 -3 -2 -1 -4
Cause Remedy
– Inner junctions not
sufficiently wetted with
bridge electrolyte
– Fill up bridge electrolyte until the inner
junctions are covered with bridge
electrolyte
– Inner junctions encrusted – Leave the bridge electrolyte to react on
the inner junctions for some hours until
the crusts have dissolved.
– Ground junction
contaminated
– Rinse ground junction with bridge
electrolyte
– Cable broken – Exchange the electrode
Cause Remedy
– Membrane surface
contaminated
– Clean the membrane surface (see
M
AINTENANCE
)
– Conditioning time too short – Extend the conditioning time
– Standard solutions too old – Use new standard solutions