Thermo Fisher Scientific Ion Selective Electrodes Nitrate - Manual (Page 16)

Instruction Manual Nitrate Ion Electrode
14
TROUBLESHOOTING HINTS
Symptom
Possible Causes Next Step
Out of Range defective meter check meter with shorting strap
Reading (see meter instruction manual)
defective electrode check electrode operation
electrodes not unplug electrodes and reset
plugged in properly
reference electrode be sure reference
not filled electrode is filled
air bubble on remove bubble by
membrane re-dipping electrode
electrodes not in put electrodes in
solution solution
Noisy or Unstable defective meter
check meter with
Readings (readings shorting strap
continuously or
rapidly changing) air bubble on
remove bubble by
membrane re-dipping electrode
defective electrode replace electrode
ISA not used use recommended ISA
meter or stirrer ground meter or stirrer
not grounded
electrode exposed soak electrode in
to interferences nitrate standard
outer filling fill electrode to
solution level level just below
too low the fill hole
Drift (reading
samples and standards allow solutions to come to room
slowly changing at different temperatures temperature in one direction) before
measurement
electrode exposed soak electrode in
to interferences nitrate standard
incorrect reference use recommended
filling solution filling solution