¦¡ Measured Radon In The Air Pulse Ionization Chamber Developed

Relating to environment protection and human health, the study in radon and its progeny is a hot topic in recent years. The measurement to radon and its progeny involves many fields in different kinds of subjects, such as nuclear technology, electronics, geoscience, environment science etc.Intelligent nuclear instrument has been a dominant developing direction of radioactivity measurement instrument. The instrument for radon measurement of air pulse ionization chamber, based on the theory that alpha rays decayed by radon and its progeny can ionize the air molecules, can measure the radon concentration accurately.This paper introduces the measuring principle, system structure and system performance of the instrument for radon measurement in detail. It is calculated according as the quantity of air molecules ionized by the alpha rays decayed by radon and its progeny as the air is inhaled to the ionization chamber by the air pump. The system contains alpha detector, amplifier, P89C60X2BN MCU, LCD, keyboard, RS-232C serial communication, real-time clock, power supply and so on. It can work either in dynamic or in static state and it also has the functions such as parameter setting, clock setting, data real time displaying, saving, accessing, up sending etc. This instrument is portable and low-power and can make spot analysis. By using the standard radium source airproofed for a period of time as the criterion, this instrument is calibrated and feasibility and practicality of this instrument are proved through the experiment.