The reference instrument in radon monitoring

The new generation of AlphaGUARD offers high detection efficiency in radon monitoring, a wide measurement range (2 – 2 000 000 Bq/m³), fast response and permanent, maintenance-free operation with long-term stable calibration.

In addition to the radon concentration, AlphaGUARD simultaneously measures and records ambient temperature, relative humidity and atmospheric pressure with embedded sensors.

Optimal ergonomics, high responsiveness and a large digital display make AlphaGUARD a reference device to perform measurement and analysis everywhere from a lab to the field. 

  • Reference instrument with high sensitivity

  • Calibration stability guaranteed for 5 years

  • High performance for versatile applications

  • Maintenance-free operation

New Features 

  • Modern design

  • Added data outputs (usb etc.)

  • Access everything via the front panel

  • Internal pump as standard

  • Graphical display for real time analysis.

AlphaGUARD is suitable as reference device and offers the following features:

  • Quality on highest level
  • Long term stable calibration factor (guaranteed 5 years)
  • Calibration traceable to different national standards (PTB, NIST, NPL)
  • Inbuilt quality assurance system for permanent validation of system operation and data
  • Fast transient response
  • Automatic background correction
  • No sensitivity to high air humidity

Radon monitoring for all purposes


  • Research & Specific applications, calibration labs
  • Nuclear & NORM industries (mining, nuclear waste, oil & gas industry...)
  • Monitoring Radon in homes& workplaces


  • Soil measurement - Emanations from the underground are measured with the gas soil probe
  • Radon progenies - Radon progeny concentration is measured with AlphaPM
  • Water measurement - Radon gas in water is controlled with AquaKIT
  • Air measurement - Thoron gas discrimination and measurement mode available

AlphaGUARD incorporates a pulse-counting ionization chamber (alpha spectroscopy).

Through optimal geometry of the chamber and intelligent signal evaluation this radon monitor is suitable for continuous monitoring of radon concentrations between 2 – 2 000 000 Bq/m³.

The DSP (Digital Signal Processing) technology provides highly effective differentiation ability between “real” radon data and all kinds of artefacts.

Detector: 0.62 L pulsed ionization chamber

Mode of operation: 3D alpha spectroscopy and current mode

Measuring range: 2 – 2 000 000 Bq/m³, (<0.05 - 54,000 pCi/l)

Instrument calibrator error: 3%

Sensitivity of detector: 5 cpm at 100 Bq/m3, (5 cpm at 3 pCi/l)

Detector filling system:  Design optimized for fast passive diffusion :10/60 min and flow mode : 1/10 min and overhead cycling mode

Storage capacity:

  • Up to 60 000 measurement points
  • ~ 400 days at 10 min measuring cycle
  • ~ 2 500 days at 60 min measuring cycle

Autonomy: 10 days (40 days with external battery)

Dimensions: 329 mm x 355 mm x 123 mm

Weight (incl. Internal battery): 6,2 kg (13,7 lbs)

Housing: Aluminium



The LabLogic Group will always treat your details with the utmost care and will never sell them to third party companies.

Please choose one of the following:

  • Reference instrument for radon monitoring