SN-3001-TRZL-N01-75cm Soil Tension Transmitter - RS485 Modbus, PVC Shell

This transmitter measures soil water potential (or tension), expressed in units like kPa or centibar. It indicates how hard a plant must work to extract water from the soil, which is a more direct measure of plant water stress than volumetric water content. It is ideal for scheduling irrigation based on actual plant needs.

The sensor uses the standard RS485 physical layer and the Modbus RTU protocol. You will need an RS485-to-USB or RS485-to-UART converter to connect it to a computer or microcontroller. Configure your Modbus master (e.g., PLC, data logger, or software) with the correct slave address, baud rate, parity, and register addresses to read the soil tension data.

The transmitter operates on a wide-range DC supply of 12 to 24 volts, with a low operating current of less than 20mA. This makes it compatible with common 12V or 24V DC power supplies, solar-powered systems, or battery packs used in agricultural field installations.

No, a key feature of this soil tension sensor is that its measurement principle is not affected by the presence of soil salt ions, fertilizers, or pesticides. This ensures long-term accuracy and stability without the need for frequent recalibration, unlike some capacitive or resistive soil moisture sensors.

The 75cm probe length is designed to be installed at the primary root zone depth for many crops. Installation involves creating a pilot hole with a soil auger, inserting the probe to ensure full contact with the soil, and backfilling to eliminate air gaps. The transmitter body should remain above ground for cable access.