Calibration Failure - ABB Aztec 600 User Manual

Aztec 600 aluminium, ammonia, color, iron, manganese, phosphate
Single- and multi-stream colorimetric analyzers
B.4.4 Calibration Failure
A calibration failure could be caused by almost any part of the liquid handling section of the analyzer, including the solutions.
Check/Symptom
Calibration failure after
fitting a new set of
reagents on the analyzer
Failure of a routine
calibration
84
Action
If the calibration failed after fitting a new set of reagents on the analyzer, it is possible that these have
been fitted incorrectly, a piece of tubing has become restricted during the process or the reagent
lines were not fully primed.
1. Check that the reagents are the correct type, connected correctly (reagent 1 to valve R1 etc.)
and within their shelf life.
2. Check that the calibration settings are correct and have not been modified.
1. Check the analyzer tubing for restrictions, blockages or leaks – see Appendix B.4.1, page 80.
2. Check that the reagents have been fully primed, perform a Prime Lines and Calibrate routine.
The most likely causes of a routine calibration failure are; a valve becoming blocked, a leaking piston
seal or the reagents or standards becoming contaminated.
View the failed calibration results and check against expected values:
1. Enter the Calibration Status screen of the analyzer – Press the
Diagnostics, press the
2. Check the OD Low value and the OD High value against the acceptable values – see Table
C.3, page 89 for acceptable values.
OD Low Value too High
If the OD Low value is too high, too much color is being formed when measuring the blank. This
could be due to the de-ionised water becoming contaminated, a restriction in the tubing or a faulty
valve.
1. Replace the DI water with fresh solution and prime and calibrate the analyzer.
1. Check the analyzer tubing and valves for restrictions, blockages or leaks –
see Appendix B.4.1, page 80.
OD High Value too Low
If the OD High value is too low, not enough color is being formed when measuring the standard. This
could be due to the standard becoming contaminated, a fault with the reagents, a restriction in the
tubing, a faulty valve or a leaking piston seal.
1. Check the analyzer tubing and valves for restrictions, blockages or leaks –
see Appendix B.4.1, page 80.
2. Check that the piston seal is not leaking and the glass cell is not damaged. Replace if
necessary – see Section 13.3.6, page 70.
3. Replace the reagents and standards and prime and calibrate the analyzer.
OD High Value too High
If the OD High value is too high, too much color is being formed when measuring the standard. This
could be due to the standard becoming contaminated, a fault with the reagents, a restriction in the
tubing, a faulty valve or a leaking piston seal.
1. Check the analyzer tubing and valves for restrictions, blockages or leaks –
see Appendix B.4.1, page 80.
2. Check that the piston seal is not leaking and the glass cell is not damaged – replace if
necessary – see Section 13.3.6, page 70.
3. Replace the reagents and standards and prime and calibrate the analyzer.
key and enter Monitor Status. Press the
Appendix B – Troubleshooting
key and scroll up to
key to enter Cal.
IM/AZT6CR–EN Rev. J