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User manual | H2O Transmitter
H2O ANALOGUE SENSOR FORMAT
The possibility of selecting one soil type or another is determined by the manufacturer of each
of the sensors. Being able to make this selection allows the H2O transmitter to carry out one
process or another with the sensor readings, as recommended by the manufacturer itself:
• 10HS Decagon The sensor gives you a voltage x[mV] that the H2O transmitter converts into
VWC [%] (Volumetric Water Content) using the following equation:
VWC [%] = fx5+ex4+dx3+cx2+bx+a, and depending on the type of soil:
Mineral soil:
∙ a = -1.92
∙ b = +6.69E-3
∙ c = -7.37E-6
∙ d = +2.97E-9
∙ e = 0
∙ f = 0
Sensor format 10HS
Parameter
Default value
No. of integers
2
No. of decimals
1
Sign
no
Units
%
Calibration point 1
Real value
800 mV
Logical value
00.0 %
Calibration point 2
Real value
4000 mV
Logical value
50.0 %
‒ Potting soil:
∙ a = -0.03
∙ b = -1.23E-4
∙ c = +7.05E-7
∙ d = 0
∙ e = 0
∙ f = 0
The value in [%] is converted, by the transmitter itself, to standard 4-20 mA current (800-4000
mV in Agrónic format), so that, in the controller in question, it is necessary to select the Ideal data
format according to the type of sensor and type of soil selected. It is the responsibility of the user
to change the data that characterizes said format.
• PHYTOS-31 Meter Group This sensor is for
the measurement of moisture on the leaf’s
surface (LWS: Leaf Wetness Sensor) and
delivers a value between 10% and 50% of its
supply voltage. The H2O transmitter delivers
a supply voltage of 5V, so the value that this
sensor will deliver will range between 500
mV (0%) and 2500 mV (100%). This value, in
%, is converted by the transmitter to 4-20 mA
current (800mV - 4000mV in Agrónic format).
Sensor format PHYTOS-31
Parameter
Default value
No. of integers
3
No. of decimals
0
Sign
no
Units
%
Calibration point 1
Real value
800 mV
Logical value
000 %
Calibration point 2
Real value
4000 mV
Logical value
100 %
