Samples Needing Special Preparation - Decagon Devices AquaLab 4TE Operator's Manual

AquaLab
8. Sample Preparation
change the moisture content of the sample. Covering the bottom of
the sample cup provides enough sample to get an accurate reading.
4. Make sure the rim and outside of the sample cup are clean.
Wipe any excess sample material from the rim of the cup with a
clean Kimwipe. Material left on the rim or the outside of the cup
can contaminate the sensor chamber and be transferred to subse-
quent samples.
5. If a sample will be read at some other time, put the sample
cup's disposable lid on the cup to restrict water transfer. For long-
term storage, seal the lid by placing tape or Parafi lm® completely
around the cup/lid junction.
6. Be consistent in sample preparation practices.
If you crush, grind, or slice your sample, be consistent in the method
you use in order to obtain reproducible results.

Samples Needing Special Preparation

AquaLab reads most materials in fi ve minutes or less. Some sam-
ples, however, may require longer reading times, due to their na-
ture. Th ese materials need additional preparation to ensure quick,
accurate readings. To fi nd out whether special sample preparation is
necessary, take several readings to see if readings (a and time) stabi-
w
lize. If continued readings take longer than six minutes, remove the
sample and take a reading of a verifi cation standard. Th is will ensure
the sample itself is causing the long read time, and that there is not a
problem with your instrument. If the verifi cation standard also takes
longer than six minutes to test, the chamber may be dirty. Refer to
Chapter 6 for cleaning procedures.
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