Sartorius MA35, Руководство по эксплуатации

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17
Preparation
Before drying a sample, you must carry
out the following preparations:
– Adjust against the existing measurement
system
– Prepare the sample
– Set the drying program parameters
Adjusting against an
Existing Measurement System
A moisture analysis method often
replaces another drying method (such as
oven drying method) because it is simple
to use and requires shorter analysis time .
In this case, you should adapt this
method to that of the moisture analyzer
in order to obtain values comparable to
those yielded by your standard reference
method .
Setting the Drying Program
Parameters
– By selecting the right drying program
parameters, it is possible to achieve the
same results as the standard procedure
in a much shorter time and with much
simpler operation .
Preparing the Sample
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Select a sample
Select a representative part of the whole
substance as a sample .
– Choose a representative number of
individual samples for quality control
– Choose enough samples to indicate a
trend for in-process control
If required, homogenize the product
before a sample is taken by:
– Mixing or stirring
– Taking several samples from different
areas of the product
– Taking several samples at defined
intervals
Take only one sample at a time for a
given analysis and prepare it as quickly
as possible .
In this way, it will not lose or gain
moisture as a result of the ambient
conditions .
If several samples need to be taken
simultaneously, the samples must be
sealed in airtight containers to ensure
that the storage conditions do not alter
the state or condition of the samples:
– Warm or highly volatile substances lose
their moisture very quickly .
– If you store the samples in a container,
the moisture can condense on the walls
of the container .
– If the container is too big and not filled
completely, the sample can exchange its
moisture with the air remaining in the
container .
Mix the condensed moisture back in with
a sample if necessary .
Prepare the sample
When crushing a sample, avoid any
contact with heat . Heat results in
moisture loss .
t
Crush the sample using
– Pestle
– Lab mill