Preparation
Make sure you carry out the following
preparations prior to drying a sample:
– 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 (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.
§ 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:
– repeat the analysis first 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
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