Decagon Devices AquaLab 4TE Operator's Manual page 79

be done to speed up the process. Refer to Chapter 8 for fur-
ther explanation.
4) Your sample may contain volatiles. Volatiles are known to
cause unstable readings, because they condense on the sur-
face of the chilled mirror and alter readings. Please refer to
the volatiles section in Chapter 8 for hints on reducing diffi -
culties with measuring samples with propylene glycol. If you
have further questions regarding the measurement of vola-
tiles contact Decagon.
5) A fan blade in the block chamber may be broken or bent. If
even salt standards take a long time to read, and the sample
chamber is clean, you may have a broken chamber fan blade.
Th is is especially likely if you have just cleaned the chamber.
If you suspect this may have happened, contact Decagon for
details on replacement.
3. PROBLEM:
Water activity readings on verifi cation standards are too high/low
and a linear off set adjustment cannot be made any higher/lower.
SOLUTIONS:
1) Th e thermopile in your chamber, which measures sample
temperature, may have become contaminated. Refer to Chap-
ter 6 for directions on cleaning.
2) Th e chamber mirror may be dirty. Refer to Chapter 6 for di-
rections on cleaning.
4. PROBLEM:
Message on screen displays the following:
12. Troubleshooting
73
AquaLab