Low-cost radon monitoring with validation by a reference instrument

This article reports radon tracing using a low-cost, locally manufactured smart electronic device with comparison to a reference device. Developed for radiation protection and nuclear security, the proposed device consists of a ZP 1200 Geiger-Muller (GM) tube detector with low-cost components including an Arduino microcontroller board, a DHT11 temperature (T) and relative humidity (RH) sensor, and XBee-based Internet of Things (IoT) wireless transmission modules. The reference device measures radon concentration, temperature, and relative humidity in indoor spaces. Typically, the developed device provides data of atmospheric parameters (T, RH) and the ambient dose equivalent rate H*(10). From the ambient dose equivalent rate in mu Sv/h, the radon activity concentration (in Bq/m(3)) is determined using standard and recognized conversion coefficients. The coefficients vary according to the ambient radiation strength and range from 5500 to 8900 (Bq/m(3))/(mu Sv/h). The developed device and the reference instrument were used for one month in several dwellings in the city of Yaounde-Cameroon. Periodic average values of 27.5 +/- 2.0 degrees C (developed device) and 26.2 +/- 2.0 degrees C (reference) for temperature, 74.1 +/- 6.4% (developed device) and 73 +/- 6% (reference) for relative humidity, and 1500 +/- 163 Bq/m(3) (developed device) and 1465 +/- 164 Bq/m(3) (reference) of cumulated radon activity concentrations were obtained for a 24-hour period. Statistical analyzes carried out on the results of the devices provide a linear regression coefficient of R-2 = 0.9978, demonstrating good agreement between the instruments.