2 photometry, 3 ph value / orp voltage, Photometry – Xylem pHotoFlex/pHotoFlex Turb User Manual
Page 88: Ph value / orp voltage

What to do if...
pHotoFlex / pHotoFlex Turb
88
ba75491d04
07/2006
6.2
Photometry
Measuring range
undercut or exceeded
Obviously incorrect
measured values
6.3
pH value / ORP voltage
Measuring range
undercut or exceeded
Cause
Remedy
– Program not suitable
– Select program with suitable
measuring range
– Dilute the sample
Cause
Remedy
– Measurement disturbed by
external light
– Close the external light cover.
– Cell not correctly inserted
– Insert the cell so that it is
positioned on the bottom of
the cell shaft.
– Cell contaminated
– Clean the cell
– Cell shaft contaminated
– Clean the cell shaft
– Dilution set incorrectly
– Set the dilution
– Selected program unsuitable
– Select other program
– Zero measurement incorrect
– Perform zero measurement
– Blank value incorrect
– Remeasure the blank value
Cause
Remedy
Electrode:
– Air bubble in front of the
diaphragm
– Remove air bubble
– Air in the diaphragm
– Extract air or
moisten diaphragm
– Gel electrolyte dried out
– Replace electrode
Test sample
– The pH value lies outside the
measuring range
– not possible