The Development Of A Portable Continuous Radon Monitor

The effect of Radon in air on human health has been paid wide attention. The measurement and control of radon involves many different subjects, however, to measure Radon precisely is the precondition to make defense measures.The portable continuing instrument is the fruit of this study, which is based on the theory of radon diffusing in the atmosphere. Moreover the instrument is built on the analysis of the internal and foreign state of radon instrument and the characteristics of measuring radon in air on field. The detailed work is the research of its components and test analysis of integral system performance.This thesis discusses principle of measurement, system structure and system performance of the portable instrument for radon measurement in detail. The principle of this instrument is that through the measurement of radiation of progenies of radon that diffuses into the instrument the radon concentration in air is indirectly measured. The system contains power supply, a detector, electric charge sensitive forward amplifier, main amplifier, peak hold circuit, analog-to-digital converter, micro-controller C8051F023, LCD, keyboard, RS-232 communication circuit, real-time clock, printer interface and so on. This instrument is portable and low-power and can make field analysis and field print. Its software is designed structurally, thus the operation of the instrument is easy and friendly.Finally, Using the method of calibrating instrument in a variational concentration calibrates this instrument. According to the result, the performance of the instrument is analyzed. Therefore the feasibility and practicality of this project is proved.