• Records radioactivity and determines soil moisture content
  • Updated every hour 
  • Self powered by solar panel (optionally)
  • Data is logged and processed in the cloud 
  • Rugged carbon housing
  • Moisture content of an entire field

Radiation Sensor

  • 100 ml CsI crystal
  • Wireless connection via WIFI and Bluetooth
  • Powered by solar panel 


  • Data stored and processed in cloud

System Data

  • Housing: Carbon fiber; end caps: Anodized aluminum


The Medusa gamma Soil Moisture Sensor is a gamma-ray spectrometer especially designed for stationary recording soil moisture content. The system is particularly designed for agricultural purposes. It is able to log the moisture content on an hourly basis and generates input for decision making on adding water to the field. 

The system is stand-alone and can be delivered with a solar panel to account for energy consumption. The height of the detector can be adjusted to the size of the field, however most commonly a detector height of 3 meters is used. The data recorded by the detector is automatically uploaded to a cloud service by an internal 4G connection.   

The major advantage of this sensor over standard soil moisture sensors is the large field of view. The gSMS gives and average moisture content of an entire field.  


Our MS-series of Gamma-ray spectrometers are used to measure several properties of agricultural fields on a regular basis. These measurements involve mapping of soil properties on various platforms, ranging from walking surveys to quad borne surveys, drone borne surveys or airborne surveys at large altitude. In this mapping, changes in soil moisture have a very small effect on the measured results. In general, these effects are so small that they are negligible. However with a precise stationary measurement, these changes can be measured. 

Figure 1: The concentration of radionuclides decreases in wet conditions

To detect the gamma-rays a 100ml CsI scintilation crystal installed in the detector. To lower the power use the raw data is directly send through a data connection to a cloud service. It can be on a webserver, that provides access to the multiple functions of the device, i.e.

  • Set-up of the system;
  • Status view to inspect data and functioning of the system;
  • Short and long measurement modes;
  • Download view to allow retrieval of recorded data.

This webserver can be accessed via any standard webbrowser platform.


  • Measures average soil moisture of an  area between 0.2 -1 hectare, depending on the height of installation
  • Measures average soil moisture of the top 30 cm.
  • Is independent of atmospheric conditions.
  • Measures one sample per hour.