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Instruction Manual – ATS / BTS Moisture Analyzers
1.
A sample of a given substance must be a good representation of the material. Drawing and preparing a sample is a
very important process as it may affect the repeatability of measurements. The most common method of
homogenizing a sample is mixing. Another method is to draw a few samples from different but specific points in a
substance and calculate an average value, or to draw a few samples from different points in a substance, mix them,
and draw a sample from the mixture.
Note
: The sampling method depends on the type of research being performed. In quality control, usually many
representative samples are analyzed. In production control, it is enough to confirm sampling repeatability.
2.
When preparing a sample, it is important the sample does not absorb moisture from the surrounding environment –
thus preparation time should be as short as possible.
Note
: If necessary to analyze more than one sample at the same time, the samples should be placed in separate
hermetically sealed plastic bags or containers. Make sure the sample does not lose moisture while it is inside the
container (the container or plastic bag should not have much air in it).
3.
Tools and instruments used in the preparation process may affect measurement accuracy. Do not use tools that
transmit heat as this can cause the sample to lose moisture before the actual analysis. Use only special grinders and
mixing instruments. When drawing a sample from a liquid containing solid materials, use a glass mixer, spoon, or
magnetic mixer.
4.
To analyze moisture content, place the sample on the disposable pan provided with the unit and place it in the dryer
chamber. Using disposable pans helps to avoid the false results that may be caused by the residue left from previous
samples.
5.
A sample should be always thin and distributed uniformly throughout the pan so that the heat penetrates equally all
over the sample and dries the entire sample effectively.
A sample that is thick or unevenly distributed will cause the top surface of the sample to be overly dried and possibly
burned while the sample underneath the top surface remains wet. This may result in the sample being burned or the top
surface hardening which will make the analysis more difficult as well as inaccurate.
A sample should always be placed in uniform layers measuring 2 to 5mm in thickness and weighing 5 to 15g, depending
on the substance. When drying liquids, pastes, or substances that may melt or lose liquid during the drying process, the
use of glass fiberfilters is recommended as filters ensure equal liquid distribution. When solid materials are being dried, a
glass fiberfilter will prevent the sample from burning.
Chapter 9: Preparing the Sample
