DMM600 Duff Moisture Meter
7.5.3.2 Indicators
Three circles provide serial communications information.
The left circle indicates which serial communications port is selected. The
circle is green when the connection is successfully made.
The TX circle is green during transmission from the computer to the DMM600.
The RX circle is red during transmission from the DMM600 to the computer.
7.5.3.3 Command Buttons
Send Calibration Coefficients
sends calibration name (maximum of 4
characters) and the user-specified calibration coefficients to the DMM600.
Receive Calibration Coefficients
receives and displays calibration name and
calibration coefficients from DMM600.
Read Battery Voltage
reads voltage of 9 volt battery in DMM600 and displays
value.
Reset DMM600 calibration
removes any user-defined calibration and sets
calibration to factory default.
7.6 Calibration
7.6.1 DMM600 Standard Calibration
FIGURE 7-3 shows the response of the DMM600 as described using the
standard calibration that was derived by Campbell Scientific using duff from
lodgepole pine, spruce, Douglas fir, larch and oak vegetation types. The error
bars indicate that the measurement accuracy decreases as water content
increases. The accuracy is approximately
±
4.0% at 60% volumetric water
content and approximately
±
1.5% at 30% volumetric water content.
Measurements on materials that are highly heterogeneous in fragment size will
provide less accurate results.
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