Purpose
The MA45 moisture analyzer can be
used for quick and reliable deter-
mination of the moisture content of
materials of liquid, pasty and solid
substances using the thermogravimetric
method.
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Basics of Moisture Analysis
Material
The moisture of a material is often mis-
takenly equated with its water content.
In fact, the moisture of a material
includes of all the volatile components
which are given off when the sample is
heated, no matter the kind of material.
Among such volatile substances are:
– water
– fats
– oils
– alcohols
– organic solvents
– flavorings
– products of decomposition
(when a sample is overheated)
There are many methods for determin-
ing the moisture content of a sub-
stance. Basically, these methods can be
divided into two categories: absolute
and deductive methods.
When absolute methods are used, the
moisture content is directly determined
(for example, as a weight loss registered
during the drying routine). These
methods include oven drying, infrared
drying, and microwave drying. All
three of these methods are thermogravi-
metric.
When deductive methods are used, the
moisture content is indirectly deter-
mined. A physical property related to
the moisture in the substance is meas-
ured (e.g., absorption of electromag-
netic rays). These methods include
Karl-Fischer titration, infrared spec-
troscopy, microwave spectroscopy, etc.
Thermogravimetry is the process of
determining the loss of mass that
occurs when a substance is heated. In
this process, the sample is weighed
before and after being heated, and the
difference between the two weights
determined is calculated.
In a conventional drying oven, circulat-
ing hot air warms the sample from the
outside toward the inside. Efficiency
is lost during drying because as the
moisture evaporates, it cools the sample
surface.
By contrast, infrared rays (IR rays) pene-
trate a sample without being impeded.
Having reached the interior of a sample,
they are converted into heat energy,
which stimulates evaporation, thus dry-
ing the sample.
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