The latest development in monitoring soil moisture are sensors to determine the volumetric water content by measuring the dielectric constant of the media through the utilization of capacitance/frequency domain technology. This technique is a cost-effective, reliable, fast and accurate soil moisture measuring method. In contrast to the TDR-method (Time Domain Refelctometry), the FDR technology is based on determining the difference, not the time, between emitted and reflected electromagnetic waves. This is the basis for the calculation of the volumetric water content of the measured media. The FDR sensor provides immediate measurement results and can be used as
• on-spot and mobile measurement system in combination with a hand-held meter
• stationary and continuously soil moisture monitoring device with connected datalogger

The sensors are maintenance-free and frost-proof. Good soil-to-sensor contact is essential for accurate measurements. The sensor is pushed directly in the undisturbed soil. Because the moisture is measured along the entire length of the sensor, the user can easily determine the moisture in various soil profiles. When installed vertically, the soil moisture reading is the average across the length of the sensor.

According to the estimated application, two different sensors are available:

- EC-5 sensor for use in greenhouses (potting soils, peat substrates, rockwool, etc),
- HS-10 sensor for use in mineral soils (outside)
The hand-held meter MST 3000 can be used for readout of both sensors. The clearly readable LEDs display the result in % VWC (volumetric water content). According to the used sensor and the type of soil, various calibration settings can be selected.

The Datalogger SW 3000 combines the state-of-the-art sensor technology with intelligent data communication. Two models are available: data transfer via Bluetooth on the mobile phone or alternatively via GPRS modem and SIM card directly to an internet data base.