• Measures field bulk density

  • Simple to use

  • Real-time measurement

  • Lightweight and rugged housing


  • CsI crystal radiation sensor

  • 22Na source

  • Source is free to use

  • No license or dosimetry badge needed 

  • Wireless connection via bluetooth

  • Battery-powered

  • Measures ± 8 cm around sensor

  • Can measure at 5 cm intervals


  • On-board data logging

  • Set-up, control and viewing of data via app

System Data

Housing: aluminum

Temperature: -40 °C to +85 °C
Waterproof: IP68 protected

Charge power:

Battery capacity: 12 hours continuous measurement

Dimensions: 30 mm  x 1280 mm (L)
Weight: 3 kilogram


The Medusa Radiometrics MS-RhoC 3.0 measures soil bulk density in the field. Soil bulk density is an important physical soil health indicator and generally used for assessing soil quality. The MS-RhoC 3.0 measures the backscatter of gamma radiation emitted from a (low-active) source, which can be used without legislation. The sensor can measure up to 1m deep and only needs a hole of 3cm diameter for such a measurement. With this sensor, there is no need for a soil pit or any laboratory work to determine soil bulk density, the sensor provides the measured densities during measurement in the field. This allows the soil scientist to gather more information in the vertical, as well as the horizontal scale.

The housing is rugged, easy portable and can be operated by any fieldworker. 

System Operation

The system is designed for easy operation in field conditions. Before measurement, a small hole (3 cm diameter) should be drilled by a hand auger or other coring device. The sensor should be placed in the hole and measures density at each position. Within 30s accuracy of ~0.01g/cm3 can be achieved. A shorter measurement period will result in a lower accuracy. For correction to dry bulk density values, additional moisture measurements should be taken. Data acquisition is done with an app on a mobile logging device or any smartphone. A project can be set-up, automatic recording can be set and a list of pre-defined measuring depths can be loaded. After measurement, the soil field bulk densities can be easy transferred by mail, whatsapp or messaging. Data is stored on the mobile logging device or smartphone, which would typically allow for thousands of hours of continuous logging of data. 


The system comprises a CsI scintillation detector connected to a tailor-made spectrum processing unit. The system is powered by an internal battery, that can be recharged with an USB adapter. The battery allows for over 12 hours of continuous measurement.

The unit communicates with an app 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;
  • Project management, setting up measuring intervals;
  • Download view to allow retrieval of recorded data.

The system is used for mapping field bulk density at various projects. Comparison with ring samples gives excellent results. 

Soil bulk density measurements with RhoC

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