Soil Moisture sensors work by measuring the moisture content in the soil using various techniques. The two most common types of soil sensors are capacitance-based sensors and resistance-based sensors. Here's how each type works:

1. Capacitance-based Soil Moisture Sensors:

   - Capacitance-based soil sensors measure the dielectric constant of the soil, which is influenced by the soil's moisture content.

   - These sensors consist of two or more electrodes that are inserted into the soil. One electrode acts as a transmitter, applying an electrical charge to the soil, while the other electrode(s) act as receiver(s).

   - When the soil is dry, it has a lower dielectric constant, and the electrical charge applied by the transmitter electrode is not affected much. However, when the soil is moist, it has a higher dielectric constant, altering the electrical charge received by the receiver electrode(s).

   - The change in electrical charge is correlated with the soil moisture content, and the sensor provides an output signal that represents the moisture level in the soil.

2. Resistance-based Soil Moisture Sensors:

   - Resistance-based soil sensors measure the electrical resistance between two or more electrodes inserted into the soil.

   - These sensors typically include two metal probes that act as electrodes. The resistance between the probes is influenced by the soil's moisture content.

   - When the soil is dry, it has high resistance to electrical conductivity due to the absence of water. As the soil becomes moist, the presence of water decreases the resistance, allowing for better electrical conductivity between the probes.

   - The resistance value is inversely related to the soil moisture content, and the sensor provides an output signal that represents the moisture level in the soil.

Both capacitance-based and resistance-based soil sensors convert the measured data into electrical signals. These signals can then be processed, interpreted, and displayed as soil moisture readings on a connected device or transmitted to a central monitoring system for analysis.

Agriculture Sensors Catalog

Agriculture-Sensors-Catalog-NiuBoL-2024.pdf