11 TROUBLESHOOTING WP4C
fan blade. This is especially likely if you have just cleaned
the chamber. If you suspect this may have happened, contact
METER for details on replacement.
3. PROBLEM:
Water potential readings on KCl standards are too high or low and
a calibration adjustment cannot be made any higher or lower.
SOLUTIONS:
• The thermopile in your chamber, which measures sample tem-
perature, may have become contaminated. Refer to Chapter
10 for directions on cleaning.
• If you are not using METER’s KCl verification standards, high
readings may indicate that the salt solution you are using is
not in equilibrium.
4. PROBLEM:
Message on screen displays the following(example):
SOLUTION:
• The sample is too dry for the instrument to read accurately. If
your sample has a water potential that is above the detection
limits of the instrument, this message will come up. Essentially,
it means that there is not enough sample moisture to condense
on the mirror and provide a reading.
• The mirror may be dirty. Try cleaning the mirror and chamber
and measuring the sample again.
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