56
How to obtain the best results - Section 8
Ramp drying
Ramp drying is selected if substances are not
stable on exposure to the full heating power
of the halogen radiator at the start. In ramp
drying, sensitive samples are prevented from
decomposition by the gentle heating. Ramp
drying can also be used successfully with
substances which form a skin.
Fast drying
The fast drying program is suitable for
samples with a moisture content between
5% and 15%. In fast drying, the radiator
power exceeds the set temperature value
during the first minute following the start of
drying. This compensates the endothermic
heat of vaporization and accelerates the
drying process. Note that the sample must
contain sufficient moisture during the first
minute to cool it.
Step drying
The step drying program has a use similar to
that of fast drying. The duration of the exces-
sive temperature stage and the temperature
value are freely selectable. It is used primarily
with samples with a moisture content greater
than 15%.
A alternate application possibility lies in the
selective determination of the moisture at
different temperatures. Gypsum, for example,
releases only its surface water at 50°C,
whereas the water of crystallization can not be separated until 168°C. With this drying program, it is thus possible to
determine the surface water and the water of crystallization separately within the same measurement by a controlled
temperature profile.
Fast drying
Step drying
Ramp drying
To Next Page
Loading...
