Campbell Scientific UT20 and UT30 Tower-based Weather Stations - Manual (Page 62)

UT20 and UT30 Tower-based Weather Stations
8.5.16 257 Soil Moisture Sensor
1. Soak the sensor end of the 257 in irrigation water for 12 to 14 hours.
Allow the sensor to dry for 1 to 2 days after soaking and repeat the
soak/dry cycle twice to improve sensor response. Always install a wet
sensor.
2. Install the sensor into soil representative of the field conditions you wish
to monitor. Avoid high or low spots. Placement south of the weather
station mast (northern hemisphere) will avoid the effects of the mast
shade. Installation in the root zone is best if measurements are used for
irrigation purposes.
3. The 257 should be removed from the soil prior to harvest or cultivation
operations to avoid damaging the sensor or sensor cable. Remove when
soil is moist.
FIGURE 8-31. 257 Soil Moisture Sensor
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