SMS-5P Soil Moisture sensor

Overview

The SMS-5P sensor measures the dielectric constant of the soil in order to find its volumetric water content. It does this by finding the rate of change of voltage applied to the sensor once it is buried in the soil. There are other probes that measure water content this way, but the SMS-5P probe is the only one of its kind to have a comparatively low sensitivity to saline and temperature effects in the soil. And its extremely high resolution makes it possible to accurately monitor water use daily or even hourly.

The SMS-5P operates at a high frequency (70 MHz). This allows it to be used in any soil type and in soils with varying degrees of EC (up to 8dS/m). Its typical accuracy in all soil types without calibration is ±3%. With calibration, it is 1—2%.

The sensor has standard 5-m cable with the IP-67 BINDER plug for easy and troublefree connection to the datalogger.