AF043-01
US Patent 5148125
Revision Date: 14 March, 2001
4
General
The Frequency Output sensors provide a signal that represents soil moisture in
volumetric percent.
The output signal is a frequency in the range 10 pulses per minute (ppm) to 130 ppm,
which represents soil moisture of 0 to 60%.
While power is applied the sensor takes one measurement every minute.
The model SI.60 sensor signal has an output designed for connection to low level
electronic circuits only. For devices requiring a clean contact input or higher voltages,
use the Aquaflex Frequency Interface (SI.80) which converts the low level signal to a
relay output.
Electrical Connection
Wire Colour
Description
Type
Connection
Red
Sensor Power
Input to sensor
+Volts
Black
Sensor Ground
Input to sensor
0 Volts (ground)
Violet
Frequency signal
Output from sensor
Frequency or pulse input
Yellow
Unused
Factory use only
0 volts (ground)
Connect the sensor to the data logger/irrigation controller as shown below.
Yellow
Violet
Black
Red
+
v
ol
ts
0 v
ol
ts
(G
rou
nd
)
F
req
ue
nc
y
Input
This and the following pages are relevant only when the sensor is
used for Frequency Output (i.e. for connection to a third party
datalogger, weather station, controller etc)
