Manual
9
4 Preparation
4.1 Preparation of sample
You should always prepare only one sample for measurement to avoid that it loses moisture to the
environment or absorbs air humidity. In case several samples have to be taken at the same time, they
should be put into airtight containers to make sure their characteristics do not change when stored.
Spread the sample on the sample pan
evenly
and in a
thin layer
to get reproducible results.
Uneven application of the sample causes inhomogeneous heat distribution in the sample to be dried. This
means that the sample is dried incompletely or that the drying time is increased. Due to piling material,
the upper layers will heat up more strongly, which will cause combustion or incrustation. An excessively
high thickness of the layer or possible incrustations prevents the moisture from leaving the sample. The
residual moisture makes the measurement results non-verifiable and non-reproducible.
4.2 Tools for sample preparation
The tools and instruments used for sample preparation have a huge effect on the accuracy and reliability
of the measurement. You should avoid tools with heat-conducting properties, i. e. which are able to
transfer heat to the sample. Improper handling and preparation of the sample will falsify the end result of
the measurement.
4.3 Disposable aluminium sample pan
To be able to measure the moisture content of the sample, the sample should be spread on the sample
pan evenly and then be placed in the drying chamber of the moisture balance. Re-using a sample pan
can falsify the end result of the measurement because of the adhering residues.
4.4 Spreading of the sample
ATTENTION:
The samples should not exceed a thickness of 8 mm and a diameter of 90 mm.
If the max. height of the sample is exceeded, this can lead to combustion or incrustation of the
sample.
The sample should be spread on the sample pan evenly, ideally in layers of 2 … 5 mm.
Make sure that the temperature probe, which is located in the cover of the moisture balance,
does not touch the sample as this will falsify the result.
Solids:
- Spread powdery and grained samples evenly on the sample pan.
- Crush coarse-grained samples using a mortar or similar device. Avoid any heat supply when
crushing the sample as this will cause moisture loss.
Liquids:
For liquids, pastes or melting samples, it is recommended to use the glass fibre filter.
