radim 3Atechnical info

The Radim 3A is a sophisticated Radon Monitor that was specially conceived for professional and scientific users. The Radim 3A is the result of more than 20 years experience in the development and manufacturing of professional Radon Monitors.

In addition to the Radon-222 concentration the Radim 3A continuously detects and records the following parameters: temperature, air pressure and relative humidity. The radon measurement is based on the principle of electrostatic deposition of the radon decay product Po-218 on the surface of a Si-semiconductor alpha-detector and the subsequent determination of the Po-218 activity by means of alpha- spectrometry.


The high precision of the measurement is effected by the large volume of the metering chamber and its optimised geometry. Due to the specific determination of the short lived decay product Po-218, the Radim 3A Radon Monitor has only a very short response time to even strong variations of the radon concentrations. During a measurement the values of the detected radon levels are recorded in intervals. The length of these measurement intervals is freely adjustable from 10 minutes to 24 hours, in steps of 10 minutes. The results of all individual measurement intervals are finally stored in blocks which are automatically generated each time a radon measurements is started and stopped.

The length of a radon measurement can be freely selected and it is only limited by the memory capacity of the Radim3A Radon Monitor. The memory of the Radim 3A can store results of 16.096 individual measurement intervals which, for example, represents a total measurement period of 22 months with measurement intervals of 1 hour. The Radim3A Radon Monitor can be continuously operated with the mains adapter or for a period of approx. 40 days with the integrated rechargeable NiMH-batteries.

The radim3A is equipped with an LCD display and three control buttons for the easy programming of the parameters and the direct reading of the measurement results. Radim 3A software program: The very user-friendly software program for the Radim 3A Radon Monitor is already included in the delivery. It is conceived for the easy readout and analysis of the results and it also allows simple operation and programming of the Radim 3A.

radim screen

All measured data can be displayed as graphs or as charts. For the analysis of freely selectable specific sections of a measurement, the software allows to define individual regions of interest (ROI). All relevant statistical parameters are automatically displayed for the selected ROI. The software program further enables an easy export of all measured data to MS Excel files. The Radim 3A software program can be used with all PCs working with Microsoft Windows systems software.

Product Specification
Measurement sensitivity 0,8 count/hour/Bq.m-3
Measuring range MDA – 150 kBq/m3;
  MDA = 30 Bq/m3 per 1 hour measurement
Measurement uncertainty < 2% at 3000 Bq/m3 per 1 hour measurement;
  < 7% at 300 Bq/m3 per 1 hour measurement
  < 20% at 30 Bq/m3 per 1 hour measurement
Measuring algorithm quick , calculated from RaA
Measuring relative humidity range 10 – 90 %
Measuring temperature range +5 to + 60 °C
Measuring pressure range 750 to 1150 hPa
Controlling LCD display , three buttons, PC via RS232
Records saving interval in monitor 10 min – 24 hours
Results memory capacity in monitor 16096
Powering Accumulator life 210 days or power adapter 230V/50hz
Dimensions 230 x 170 x 90 mm; 2,5 kg