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

Cadmium Electrode Instruction Manual
16
TROUBLESHOOTING GUIDE
The goal of troubleshooting is the isolation of a problem through checking each of the system
components in turn: the meter, the glassware, the electrodes, the standards and reagents, the sample,
and the technique.
Meter
The meter may be checked by following the check-out procedure in instrument instruction manual.
Glass-ware
Clean glass-ware is essential for good measurement. Be sure to wash the glass-ware well with a
mild detergent and rinse very well with distilled or deionized water. Clean glass-ware will drain
without leaving water droplets behind.
Electrodes
The electrode may be checked by using the procedure found in the sections entitled
Electrode
Slope Check.
1. Be sure to use distilled or deionized water when following the procedures given in
Electrode Slope Check.
2.
If the electrode fails to respond as expected, see the sections on
Measuring Hints
and
Electrode Response
. Repeat the slope check.
3.
If the electrode still fails to respond as expected, substitute another cadmium ion electrode
that is known to be in good working order for the questionable electrode. If the problem
persists and you are using an electrode pair, try the same routine with a working reference
electrode.
4.
If the problem persists, the reagent may be of poor quality, interferences in the sample may
be present or the technique may be faulty. (See
Standards and Reagents, Sample,
and
Technique
sections below.)
5.
If another electrode is not available for test purposes, or if the electrode in use is suspect,
review the instruction manual and be sure to:
- Clean and rinse the electrodes thoroughly.
- Prepare the electrodes properly.
- Use the proper filling solution.
- Adjust the pH and the ionic strength of the solution by the use of the proper ISA.
- Measure correctly and accurately.
- Review
TROUBLESHOOTING HINTS
.
Standards and Reagents
Whenever problems arise with the measuring procedure that has been used successfully in the past,
be sure to check the standard and reagent solutions. If in doubt about the credibility of any of the
solutions prepare them again. Errors may result from contamination of the ISA, incorrect dilution,
poor quality distilled/deionized water, or a simple mathematical miscalculation.