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Required fields*

What are the units of output of soil moisture sensor?

I want to use a soil moisture sensor using arduino uno R3. I am using the analog output. The values are in the range of 100 to 1300 as in the readings mention in this question.

May I know what exactly these numbers mean? I read in a website that:

Most soil moisture sensors are designed to estimate soil volumetric water content based on the dielectric constant (soil bulk permittivity) of the soil.

So what are the units? Basically I want to base an estimate for the normal amount of soil moisture for typical loamy soil and I don't understand how to base this threshold based on the readings given by the sensor. It would be greater help if someone actually knows what an appropriate soil moisture threshold is for loamy soil.

I searched on the internet but the closest i could come to answers was this table and this particular entry:

Table 1.1. Typical field capacity and wilting point values (m^3 m^(–3)) for different soil textures

Soil texture| Field capacity| Wilting point| Available water

Loam |0.27| 0.12| 0.15|

I am so sorry if I seem confused but I am very new to the whole of sensors and electronics This is the sensor that I am making use of

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So what exactly are the outputs obtained in the question I had linked? Were they resistances?

bobthebuilder
– bobthebuilder

2020年04月05日 14:49:17 +00:00
Commented Apr 5, 2020 at 14:49
They are the ADC values that equate to the voltage that is read from the sensor which is related to the resistance of the soil and the resistance of the (unknown) resistor in the sensor circuit.

Majenko
– Majenko

2020年04月05日 14:54:07 +00:00
Commented Apr 5, 2020 at 14:54
You could calibrate the sensors by measuring the output value in soil of known moisture but it probably wouldn't be worth it because those sensors corrode. There are some very inexpensive capacitance sensors available which would be better

haresfur
– haresfur

2020年04月09日 03:19:35 +00:00
Commented Apr 9, 2020 at 3:19

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