Campbell Hydrosense, Instruction Manual

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HydroSense
4
VWC 0% P12cm
Period 0.77ms
MENU
SELECT
In Water Content Measurement Mode, MENU is used to select
the rod length. In the Water Deficit Mode, MENU is used to
select the site number and to store reference water content
values.
•
To save power, HydroSense automatically goes into sleep mode after
approximately two minutes of inactivity. Pressing the READ button wakes
the unit and makes a measurement.
4. Water Content Measurement Mode
4.1 Introduction
The Water Content Measurement Mode displays the measurement result as
percent volumetric water content and also shows the period of the probe output
in milliseconds. The HydroSense operating system applies standard
calibrations to convert the probe response to volumetric water content. The
calibrations were derived from laboratory measurements in typical agronomic
soils. Section 6.2 discusses the soil factors which can affect probe response
such that standard calibrations do not work well.
4.2 Display Information
VWC 22% P12cm
Period 0.93ms
Volumetric
Water
Content
Probe
Rod Length
Probe
Output
Period
The two-line display provides the following information
1) The volumetric water content in percent (VWC). See Appendix A for
definition of water content.
2) Which probe rod length is selected (see Section 4.4 for rod length
selection).
3) The period of the square wave output from the probe in milliseconds.