Campbell Scientific HydroSense® Soil Water Content System (CS620, CD620) - Manual (Page 8)

HydroSense Soil Water Measurement System (CD620, CS620)
and hold the MENU button then press the READ button. Release both
buttons. Unless the mode is changed again, HydroSense will be in Water
Content Measurement Mode when READ is next pressed to wake the
unit.
• While holding the probes so rods are in free air, press READ. The VWC
displayed should be between -3% and 3%.
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
4