what is a soil moisture sensor?

soil moisture sensor with probe - Renke

Soil sensors are an important tool for detecting soil health, which can reflect the current soil moisture, temperature, salinity, or fertility in real-time. Provide data support for soil moisture monitoring, agricultural irrigation, and forestry protection industries. According to different measurement elements, it can be divided into four types: soil moisture sensor, soil temperature, and humidity sensor, soil moisture conductivity sensor, and soil temperature and humidity conductivity sensor. These sensors can be used with our self-developed soil recorder.

Four types of soil moisture sensor:

The soil moisture sensor is the most common device to measure soil moisture content. It can be connected with related instruments to become a plug-and-measure portable soil moisture meter, or it can be connected to a general data collector to realize long-term dynamic monitoring. Our soil moisture sensor adopts the FDR frequency domain reflection principle, which makes the measurement faster and more accurate.

Probe length: 70mm

Probe diameter: 3mm

Probe material: 304 stainless steel

Sealing material: epoxy resin (black flame retardant)

Cable length: standard two meters

Protection level: IP68

Soil moisture measurement area: within a cylinder with a radius of 7cm centered on the central probe

The soil temperature and humidity sensor can measure the two elements of soil temperature and humidity at the same time. It is a sensor for agriculture. The soil temperature is closely related to the growth and development of crops, the decomposition of fertilizers, and the accumulation of organic matter. It is an important environmental factor in agricultural production..

The soil moisture conductivity sensor can measure the conductivity and moisture value of the soil and can be used for the conductivity of water and fertilizer integrated solutions, as well as other nutrient solutions and substrates.

The soil temperature humidity and EC sensor is an important tool for observing and studying the occurrence, evolution, improvement, and water and salt dynamics of saline soil. The 3 in 1 soil sensor creatively measures salinity, moisture, and temperature together, which greatly facilitates the customer's systematic assessment of soil conditions. By measuring the dielectric constant of the soil, it can directly and stably reflect the true moisture content of various soils.

soil moisture sensor size.jpg


1. The three parameters of soil moisture content, electrical conductivity, and temperature are combined into one.

2. It can also be used for the conductivity of water and fertilizer integrated solutions and other nutrient solutions and substrates.

3. The electrode is made of specially treated alloy material, which can withstand strong external impact and is not easy to damage.

4. Completely sealed, resistant to acid and alkali corrosion can be buried in soil or directly into the water for long-term dynamic testing.

5. High precision, fast response, good interchangeability, probe insertion design to ensure accurate measurement and reliable performance.

soil moisture sensor datasheet

Power supplyDC 10-30V
Max. power consumption0.4W (12V DC power supply)
Working temperature-40℃~+60℃
Core chip temperature resistance85°C

Soil moisture

Accuracy±3% in the range of 0-53%; ±5% in the range of 53-100%
Output signalRS485, 0-5V, 0-10V, 4-20mA

Soil temperature and humidity sensor datasheet

RS485 output4-20mA, 0-5V,0-10V output
Power supplyDC 4.5-30VPower supplyDC 10-30V
Max. power consumption0.5W (24V DC power supply)Max. power consumption0.4W (12V DC power supply)
Working temperature-40℃~+60℃Working temperature-40℃~+60℃
Core chip temperature resistance85°CCore chip temperature resistance85°C

Soil moisture


Soil moisture

Accuracy2% within 0-50%, 3% within 50-100%Accuracy2% within 0-50%, 3% within 50-100%

Soil temperature


Soil temperature

Accuracy±0.5℃ (25℃)Accuracy±0.5℃ (25℃)

Soil temperature humidity and EC sensor datasheet

Power supply
DC 4.5-30V
Max. power consumption0.7W (24V DC power supply)
Working temperature-40℃~+60℃
Core chip temperature resistance85℃

Soil Conductivity

Accuracy±3% in the range of 0-10000us/cm; ±5% in the range of 10000-20000us/cm

Soil moisture

Accuracy2% within 0-50%, 3% within 50-100%

Soil temperature

Accuracy±0.5℃ (25℃)

soil moisture sensor application

The soil moisture sensor is suitable for soil moisture monitoring, scientific experiments, water-saving irrigation, greenhouses, flowers and vegetables, grassland pastures, soil rapid testing, plant cultivation, sewage treatment, precision agriculture, and other occasions.

  1. Application of soil sensor in agriculture

  2. Soil moisture sensor used with the recorder

  3. Application of Soil Moisture Sensor in Environmental Monitoring System

  4. 5 Types Of Soil Sensors

  5. How Do I Measure Soil Moisture?

How to install a soil moisture sensor?

Since the electrode directly measures the conductivity of the soluble salt ions in the soil, the soil volumetric water content must be higher than about 20% when the soluble ions in the soil can accurately reflect the conductivity of the soil. In the long-term observation, the measured value after irrigation or rainfall is closer to the true level. If performing a quick test, water the soil to be tested first, and then measure after the water is fully penetrated.

If you are measuring on a hard surface, you should drill the hole first (the hole diameter should be smaller than the probe diameter), then insert the soil and compact the soil before measuring; the sensor should be protected from severe vibration and impact, let alone knocked with hard objects. Because the sensor is a black package, the sensor will heat up rapidly (up to 50℃) under strong sunlight. To prevent the excessive temperature from affecting the temperature measurement of the sensor, please pay attention to shading and protection when using in the field or the field.

installation instructions soil moisture sensor

1. Quick Test Method

Select a suitable measurement location, avoid rocks, ensure that the steel needle does not touch hard objects, throw away the surface soil according to the required measurement depth, maintain the original tightness of the soil below, hold the sensor vertically and insert it into the soil. Do not shake left and right. It is recommended to measure multiple times for average value within a small range of a measuring point.

soil moisture sensor installation.jpg

2 Buried measurement method

Dig a pit with a diameter> 20cm vertically, insert the sensor needle horizontally into the pit wall at a predetermined depth, and fill the pit tightly. After a period of stability, measurement and recording can be carried out for several days, months, or even longer.

Soil sensor installation.jpg