DMM600 Duff Moisture Meter
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DMM600 calibration
frequency (MHz)
volumetric water content (%)
FIGURE 7-3. DMM600 standard calibration
7.6.2 User Calibration
7.6.2.1 Equipment Required for User Calibration
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plastic bags to store samples
•
a scale to measure sample weight
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containers to hold samples for weighing and while drying in oven
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a drying oven or microwave to dry samples
7.6.2.2 Calibration Procedure
The calibration requires duff samples with a range of water contents. The
collected sample will be measured with the DMM600, removed from the
DMM600 and weighed, then dried and weighed. Water will be added to the
samples to obtain samples with a range of water contents, and the measurement
process repeated on the wetted samples.
Spreadsheet file
DMM600 calibration spreadsheet.xls
is provided with the
DMM600 to assist with calibration calculations.
1.
Collect a sample of the material to be used in the calibration that is four to
five times the volume of the sample chamber. Sample chamber volume is
approximately 140 cm
3
. Place the material in a plastic bag that can be
sealed to prevent drying and let the sample set for 8 to 12 hours. This
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