USB Radon Probe TSR 4

  • Standalone measurement with saving data into own internal high capacity memory
  • Direct USB connection of probe and a PC
  • Internal high-capacity rechargeable accumulator; USB charging or power adapter 230V/50Hz
  • Probe measurement possible to turn off by switch while real time in probe keeps on
  • Diagnostic LED diodes ‘charging’ and ‘status’
  • Display and button for quick result viewing (TSR 3DNM)

TSR 4 is designed for continuous measuring of radon concentrations in buildings. Portable probe basis is a measuring chamber with a semiconductor photodetector. Radon enters the chamber by diffusion through the input filter on the bottom of probe. The probe measures in autonomous and time continuous way. It processes results in 2-minute intervals and from this counts short-term moving average of radon concentration (1 hour moving average – average of 30 2-minute process intervals). It also counts long-term moving average of radon concentration (24 hours moving average). The probe saves time records of these radon concentration values including values of humidity and temperature within its internal memory (typically at an interval of 1 hour). Next saved value is time record of measuring energy spectrum (typically at an interval of 12 hours). The probe is random for location in measured place, but generally it is put on the bottom of the probe. Bottom of the probe cannot be covered. The probe can be switched on/off by switch. LEDs „STAT“ a „CHRG“ indicate current status of probe.

The resulting values can be downloaded continuously during measurement or at once at the end of measurement. Data from the radon probe can be downloaded to a PC directly via USB interface.


  • Continuous monitor of radon volume activity – radon concentration electronic measuring 20 – 100 000 Bq/m3
  • Current radon concentrations – short-term (hourly average) and long-term (daily average)
  • Measurement uncertainty – < 13% at 300 Bq/m3 per 1 hour; < 3% at 300 Bq/m3 per 24 hour
  • Measuring algorithm – Calculation from RaA and from RaA +RaC impulses
  • Accompanying measurements – temperature (-20 ° C to + 60 ° C), humidity (10% – 90%), energy spectrum
  • Long-term records – results stored in internal big memory for the period up to 10 years, export for spreadsheet


  • USB interface – data are downloaded directly via USB into PC
  • PC application – data managing, viewing, export, Czech, English, German, Italian language


  • High Mobility – Portable device – easy equipment transfer between locations
  • Nondestructive Installation – Internal accumulator with battery life more than 1 year without charging
  • Autonomous Measuring – Each probe separately measures and stores data into internal memory
  • Data Download Options – Continuously or one-time after measurement end
  • Technical Support – Extensive services directly from manufacturer
Product Specification
Average measurement sensitivity0,25 count/hour/Bq.m-3
(method RaA+RaC; 15°C ÷ 30°C; rel. hum. 20% ÷ 40%)
Measuring rangeMDA – 100 000 Bq/m3;
MDA = 100 Bq/m3 per 1 hour or 20 Bq/m3 per 24 hours
Measurement uncertainty< 13% at 300 Bq/m3 per 1 hour;
< 3% at 300 Bq/m3 per 24 hour
Measuring chamber capacity0,176 dm3
Response rate< 30 minutes (RaA); < 3 hours (RaA + RaC)
Measuring algorithmquicker, less sensitive (calculated from RaA)
slower, more sensitive (calculated from RaA + RaC)
Measuring relative humidity range10 – 90 %
Measuring temperature range-20 °C to +60 °C
Records saving interval (probe)1- 255 minutes, default 1 hour
Results memory capacity29 999 985 records; 9 927 040 spectra
Poweringinternal rechargeble accumulator; charging via USB
Accu life after full charging> 1 year
Radon concentration results displayshort-term (1 hour running average)
long-term (24 hours running average)
DimensionØ 80 x 175 mm
WaterproofIP67 (only for electronics)
Operating conditions
Temperature-10°C to +40°C
Recommended relative humidity *10% – 75%
Maximum working relative humidity0% – 99%
Absolute humidity5-20 g/m3
Detector life50-100 million pulses
Ø 1000 Bq/m3 ->12 years
Ø 10 000 Bq/m3 ->1 year

* Increased humidity reduces the life of a charged battery.
* There must be no condensation of water in the chamber – erroneous results


Probe holder

Transport waterproof case

Outdoor cover with solar powering


Other Tools


Computer program from SURO (NRPI) for visualization and analysis of data files exported from radon concentration measurement devices made by TESLA (RADIM 3X a TSRX) and made by SAPHYMO-BERTIN (ALPHAGUARD).