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Incorrect measurement
6.3
Notes for comparative measurement with oven-drying method
The device uses a much higher sample quantity than the drying oven (12-fold to
20-fold quantity of kiln-drying method). Furthermore, to determine a more accurate
average moisture value in case of inhomogeneous material, there can be effected sev-
eral measurements within a short time.
Considering a sampling error due to the considerably smaller sample quantity as well
as the content of volatile matters (resin etc.) that are not water, the kiln-drying method
will practically reach an accuracy of approx. +/-3 %. Therefore, if the measuring values
of these two very different methods of determining the water content are compared,
differences of +/-3 % can be considered to be normal.
In the standard EN ISO 18134-2 is declared that the drying oven method provides no
absolute values, but only comparable values.
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