Thermo Fisher Scientific Ion Selective Electrodes Lead - Manual (Page 19)

Instruction Manual Lead Electrode
17
TROUBLESHOOTING GUIDE
The goal of troubleshooting is the isolation of a problem through checking each of the system
components in turn: the meter, the glass-ware, the electrodes, the standards and reagents, the
sample, and the technique.
Meter
The meter may be checked by following the check-out procedure in the instrument instruction
manual.
Glass-ware/Plastic-ware
Clean glass-ware is essential for good measurement. Be sure to wash the glass-ware/plastic-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 electrodes 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
Measuring Hints
and
Electrode Response.
Repeat the slope check.
3.
If the electrodes still fail to respond as expected, substitute another lead 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
.
Sample
Look for possible interferences, complexing agents, or substances which could affect the response
or physically damage the sensing electrode (or the reference electrode) if the electrodes work
perfectly in the standard, but not in the sample. Try to determine the composition of the samples
prior to testing to eliminate a problem before it starts. (See sections on
Measuring Hints, Sample
Requirements
, and
Interferences
.)