
TROUBLESHOOTING
Troubleshooting Checklist
28
Possible Causes
Defective meter
Electrodes not plugged in properly
Reference electrode junction is dry
No reference electrode
Reference electrode not filled
Air bubble on element
Electrodes not in solution
Static electricity
Defective meter
Meter or stirrer improperly grounded
Air bubble on element
Wrong reference electrode
TISAB not used
Samples and standards at
different temperatures
Sensing element dirty
Incorrect reference filling solution
Standards contaminated or
incorrectly made
TISAB not used
Standard used as TISAB
Defective electrode
Glassware used
Incorrect scaling of semilog paper
Incorrect sign
Incorrect standards
Wrong units used
Complexing agents in sample
Incorrect TISAB dilution
Symptom
Off-scale or
Over-range
reading
Noisy or
unstable
readings
(readings
rapidly
changing)
Drift (Reading
slowly changing
in one direction)
Low slope or
No slope
“Wrong
Answer” (But
calibration
curve is OK)
Summary of Contents for 96-09
Page 7: ...4 ...