RADWAG MA 200.3Y Moisture Analyzer - Manual (Page 68)

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The surface of such substances often may caramelize during testing
procedure. Therefore, it is recommended to use thin layer of a sample, and
moderate drying temperature.
17.1.3. Sample distribution on drying pan:
Loose materials
Dried in their natural state, i.e. in their natural
form or disintegrated. Sample disintegration causes
smaller dispersion between the following
measurements. Sample mass should not be too
high, and the sample should be evenly spread on
whole surface of the drying pan.
Liquid substances
Semi-fluid substances are dried in their natural form.
Large amount of grease (fat) occurring in some of
substances makes moisture content determination
difficult. In such case it is recommended to use
additional components, which increase sample’s
active surface and aid moisture content releasing
process from a sample. Such components are high
silica sand, blotting paper or filter. Before drying a
tested substance, initially dry the additional
component, so that its humidity is close to zero.
Solid objects
Depending on solid object’s structure (dense or
loose), moisture content determining process may
take short or long time. The size of solid’s surface
determines the speed of drying process, and
measurement reliability. Thus, the surface of a solid
object should be as large as possible. Since solid
objects release moisture through their outer
surface, sample thickness is another important
factor.
17.2. SELECTION OF DRYING PARAMETERS
17.2.1. Selecting optimum sample mass
Sample mass influences the accuracy of measurement result and
measurement time. Higher mass of a sample, causes higher amount of water
(moisture content) which needs to evaporate, and therefore measurement
time is also longer.