Radon Analytical Laboratory: Commercial and Research Capabilities

1500 L dual flow loop, two filter radon detector
1500 L dual flow loop, two filter radon detector

The radon analytical laboratory specialises in the monitoring and analysis of natural radioactivity resulting from radon (222Rn), thoron (220Rn), radium (226Ra) and their progeny.



  • Measuring radon/thoron concentrations in indoor or outdoor air
  • Measuring in situ radon and thoron emanation from rocks and soils
  • Quantifying radon concentrations in, or exhalation rates from, gaseous, liquid, solid and mixed phase samples

Please refer to the laboratory 'fact sheet' for more information.


Laboratory based facilities

'Radon rig': employs a de-emanation technique, whereby radon released from a sample is captured by activated charcoal for subsequent analysis by alpha-decay counting. The rig is used for measuring very low radon concentrations in, and radon exhalation from, solid, liquid or gaseous samples under normal pressures.

Liquid scintillation counter: A Tri-Carb 3100TR is available to quantify a broad range of radon concentrations in air and clear water samples for environmental or industrial purposes.

Gamma spectrometer: A germanium crystal gamma detector is used to measure rates of radon emanation from solid samples (sands, soils, crushed ores etc; sample grain size not exceeding 1-5mm). The difference in gamma activity of radon progeny in the sample pore space is determined over a 30-day equilibration period.

Facilities for in situ monitoring

Single-trap radon sampler: stainless steel traps, containing 115g of activated charcoal, can be exposed in situ with this portable sampler, either using the inbuilt pump, or from a pressurised source. Exposed traps need to be shipped directly back to ANSTO for analysis on our Radon Rig. 

Radon emanometer: employs the flow-through accumulator method to simultaneously measure the radon and thoron flux densities, in situ, from soil or rock surfaces over a 30 minute period.

AlphaGUARD: Five portable Saphymo GmbH Alpha Guard radon monitors are available for the continuous, hourly measurement of moderate to high concentrations of radon in air (2 – 2 000 000 Bq m-3). Although designed for indoor use in buildings, tunnels and caves, they may also be placed inside ventilated enclosures for outdoor monitoring.

Dual flow loop, two-filter radon detectors: Two models (700 L and 1500 L) of semi-portable radon detectors are available for continuous, outdoor, hourly monitoring of ambient radon in air for periods of weeks, to years. With a lower limit of detection of 30-40 mBq m-3, these detectors are suitable for monitoring atmospheric radon concentrations with a high precision down to very low concentrations (e.g marine air).

Summary of the Radon Analytical Laboratory Facilities
InstrumentMeasurementMediumAnalysis rateComments
Liquid Scintillation Concentration (sample) Liquid/gas 30 min per run20 mL samples; LLD 200 Bq m-3; up to 300 samples per run
 Single-trap sampler Concentration (in situ)Gas20 per day 1 L min-1 sampling; 60 traps available; analysis performed on radon rig
 AlphaGuardConcentration (in situGas 10-60 min per measurement LLD 2 Bq m-3
 700/1500L Rn detectors Concentration (in situ) Gas Hourly measurements  LLD 0.03-0.04 Bq m-3
 Radon Rig Concentration
Emanation (sample)
 Solid / liquid / gas 20 per day Instrumental BG <0.5 cpm; LLD depends on volume sampled
Gamma spectrometer Emanation (sample)  Solid  30 days per analysis*  0.5 kg sample, grainsize <5mm.
 Rn Emanometer Emanation 
(in situ) 
  Solid  30 min per measurementLLD = 4 mBq m-2 s-1; typically 10% measurement error.

 * Numerous samples can be counted sequentially and then left for their 30-day equilibration time.

Contact details

For general enquiries, or more detailed information regarding radon / thoron measurement capabilities, or research and commercial applications, please contact:

Dr Alastair G. Williams
Leader, Atmospheric Mixing and Pollution Transport group
Phone: +61 2 9717 3694
Email:  Alastair.Williams@ansto.gov.au