Radon Dosimetry

LBS offers two technological solutions to determine the average concentration of Radon gas activity in the air.

EIC (Electret Ion Chamber) System
The well known and reliable EIC (Electret Ion Chamber) System comprises an electrically-charged Teflon disk, charged using a system that makes the charge permanent, mounted on a plastic support that allows application onto specific, defined-volume chambers. The electrets are pairs with different sensitivities and chambers have different volumes, allowing the evaluation of the average concentration of radon gas in the air, over a long period of time: from a few days to several months. The relative simplicity of such measurement operations, and LBS’s constant attention to the checking and calibration of its own equipment, provides for extremely precise and accurate results.

​CR39 System
The CR39 system has a diffusion chamber, or container, and a nuclear track detector. The diffusion chamber only allows radon to enter, not its decay products. The chamber’s sensitive volume is optimised based on the detector’s efficiency for alpha radiation emitted by radon and progeny, depending on the length of time of sampling. The sensitive element is a PADC track detector, an organic polymer with the commercial name of CR-39. The detector has a plate which is 25 x 25 mm in size and a thickness of 1.50 mm. Each detector is supplied assembled and ready to use, they have an unique alphanumerical code stamped on the sensitive part, also repeated on the outer part of the device.


Evaluation of average concentration of Radon gas activity in the air.


  • Robustness and high level of solidity;
  • External electrostatic charge, concentration of ions outside the dosimeter;
  • Response provided regardless of temperature, humidity, dust, mechanical shocks, concentration of external electrostatic charge, concentration of ions outside of the dosimeter;
  • Possibility of choosing the measurement interval that is most suited to specific needs, including continuity between the time frame of a few days and one year, with almost negligible fading.

Technical specifications

EIC System
Sensitive part: electrets with different sensitivity (LT and ST)
Chambers: S – 210 ml / L – 58 ml
Sensitivity: from 296 Bqm3 gg to 25,160 Bqm3 gg (*)
Dynamic range: from 9,250 Bqm3 gg to 629.000 Bqm3 gg (*)
Accreditation field: (100 – 2500 kBq·h/m3).

CR39 SystemSensitive part: sheet of poly-allyl-diglycol-carbonate (PADC)
Chamber: 40 ml
Range of measurement: 20 – 40000 kBqh/m3
Accreditation Field: (100 – 3000 kBq·h/m3);

(*) Variable depending on electret chamber configuration used.



Active Measurement System**

The active measuring systems are portable electrical instruments that sample air and measure radon gas concentrations, providing almost immediate responses.
Thanks to this property, various measurement conditions can be tried in the environments (heating on/off, ventilation on/off etc) and radon concentration trends over a short period of time can be measured. Also, components that can be used with these instruments provide for radon concentration measurements to be taken in soil and water.

(*) Radiation not included in the field of application accredited by ACCREDIA