Preparation
Before drying a sample, you must carry
out the following preparations:
– Adjustment to the available measuring
system (if required)
– Sample preparation
– Setting the drying program parameters
21
Adjustment to an Existing Measuring System
A moisture analysis method often replaces another drying method (e.g., 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.
§
Perform parallel measurements: take a fresh sample and divide it in half
§
Determine the moisture content of the first half using your standard method of analysis
§
Analyze the second half of the sample in the moisture analyzer.
Use the following settings:
– fully automatic mode for the shutoff parameter
– lower temperature settings than for the oven drying method
– temperature setting for organic substances: 80 –100°C
– temperature setting for inorganic substances: 140 –160°C
$
If the result of the second analysis does not correspond to that of the first:
– first, repeat the analysis using a different temperature setting
– then use the semi-automatic mode for the shutoff parameter (for example,
with a different loss rate per 24 s)
$
Vary the shutoff parameter, if required:
– Increase end-point recognition: set the parameter to 2 mg / 24 s or 1 mg / 24 s
– Decrease end-point recognition: set the parameter to 10 mg / 24 s or 20 mg / 24 s
