Aztec 600 ISE ammonia and fluoride
Single-stream ion-selective analyzers
Appendix B – Troubleshooting
OI/AXM630–EN Rev. I
79
Low readings
Incorrect calibration
Check calibration solutions for accuracy
Ammonia probe response slow
1. Check probe and replace membrane if required
2. Check reference electrode for signs of stripping of chloridised
layer
Calibration values incorrectly input into
configuration
Check calibration input values and calibration solutions value. Use
mV Offset to give indication – the further from 0mV, the more likely
it is that the standard values are different to the true standard
concentrations
Ammonia stripping in tubing and
instrument feed lines
Check for contamination in all tubing and feed lines – clean or
replace as required
Sample contaminated
Take appropriate measures to ensure the sample is suitable for
measurement
Calibration failure
Incorrect calibration solution value(s)
entered in configuration
Enter correct value
Incorrect calibration solution(s)
Check quality – replace / remake if necessary
Insufficient / incorrect calibration
solution supply
1. Check valve manifold fluid connections
2. Check valve electrical connections
3. Check calibration solution levels and refill if required
4. Check tubing for blockages
5. Check pump speed and pump tubing for wear
Insufficient or incorrect reagent
Check levels and quality – replace if required
Faulty probe
Ammonia
&
Fluoride
– Check end of probe is clear of any possible fouling
Fluoride
– Replace membrane and recalibrate
Calibration failure
with low Gradient
Coefficient or
% Slope indication
Incorrect calibration solution(s)
As above
Insufficient / incorrect calibration
solution supply
As above
Insufficient or incorrect reagent
As above
Faulty probe
As above
Electrode insensitive
Ammonia
– Replace membrane – if symptom resists, replace
probe. See also 'Calibration failure' remedies
Fluoride
– Replace probe. See also 'Calibration failure'
remedies
Calibration failure
with High Gradient
Coefficient or
% Slope indication
Incorrect calibration solution(s)
As above
Insufficient / incorrect calibration
solution supply
As above
Fault
Possible Cause
Remedy
Table B.1 Faults, Causes and Suggested Remedies (Continued)
