Campbell Scientific 229 Water Matric Potential Sensor and CE4/CE8 - Manual (Page 27)

229 Heat Dissipation Matric Water Potential Sensor
0 100 200 300 400 500
200
100
0
100
200
10 degrees C
16 degrees C
18 degrees C
22 degrees C
24 degrees C
30 degrees C
matric potential (-kPa)
error (-kPa)
FIGURE 6-3. Measurement error for range of soil temperatures and wetter range of matric potential.
A temperature correction for the difference in temperature at time of calibration
and time of measurement is provided in the work of Flint et al., 2002. To
implement the correction, normalized temperature must be used for the
calibration variable. Normalized temperature is as defined in equation [3].
The correction procedure is an iterative method. Examples of implementing
the iterative routine with dataloggers are given in programming examples 5 and
6. The general sequence for using the temperature correction method is:
1. Determine
dry
T Δ
and
wet
T Δ
prior to calibration and with sensor
conditions as described in 6.2.1. The recommended T Δ
is the sensor
temperature after 30 seconds of heating minus the sensor temperature
after 1 second of heating.
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