Thermo Fisher Scientific Ion Selective Electrodes Ammonia - Manual (Page 20)

TROUBLESHOOTING HINTS
Symptom Possible Causes
Next Step
Out of Range defective meter perform meter checkout procedure
Reading (see meter instruction manual)
defective inner body refer to
Checking the Electrode
Inner Body
electrode not unplug electrode and reset
plugged in properly
internal filling fill outer body of electrode with proper
solution not added amount of internal filling solution
air bubble on membrane remove bubble by re-dipping
electrode
electrode not in solution put electrode in solution
Noisy or Unstable insufficient
fill outer body of electrode with proper
Reading (readings internal filling solution amount of internal filling solution
continuously or
randomly changing.) defective meter
perform meter checkout procedure
(see meter instruction manual)
bottom cap loose ensure that bottom cap is screwed on
tight enough to close gap between
bottom cap and body
defective inner body refer to
Checking the Electrode
Inner Body
air bubbles on membrane remove bubbles by redipping electrode
meter or stirrer check meter and stirrer for
improperly grounded grounding
Drift (reading slowly internal filling
ensure that membrane is installed
changing in one solution leakage properly
incorrect internal refill outer body of electrode using
filling solution filling solution shipped with electrode
total sample level dilute sample of dissolved species
above 1M
electrode in sample reduce surface area to volume ratio,
too long; NH
3
loss slow down rate of stirring, avoid