| Radon pollution is harmful to human body.The existing instruments for detecting radon gas and its progenies has the disadvantages of high power consumption,large volume,wired communication or data stored in SD card,which is not conducive to real-time monitoring and feedback of environmental air quality information.In this thesis,the study of portable instrument radon detector with multi-channel function was carried out.The main contents of this thesis are as follows:(1)The design of the system hardware:The collection chamber for radon and the analog circuit of radon progeny signal was designed.And a series linear voltage regulator circuit was designed based on the sine wave oscillator,which was used as a high voltage bias circuit for detector,and the boost circuit was designed as a high-voltage driving circuit based on the LM3524 pulse width modulation chip.A digital circuit with memory,temperature and humidity measurement,clock acquisition,Bluetooth communication and human-computer interaction had been designed.The realization of hardware provided a necessary hardware platform for the acquisition of data,analysis,processing and wireless communication.(2)The design of the system software:We had designed the digital signal processing flow of radon progeny signal,completed the design and compilation of the key program,including the Radon energy measurement and the separation counting program,the energy spectral data reader,the Bluetooth communication control program,the energy Spectrum drawing procedure,the keyboard unlocking procedure,etc.(3)The performance of prototype test:After a 40-day experiment,we tested the power performance of the prototype,Bluetooth communication and the function of the system energy spectrum measurement.The results showed that the prototype was able to measure the energy spectral data and the lowest resolution can be low to4.11%.Bluetooth communication function was realized and the overall average power dissipation was 296.4mW,the volume was 1.05 dm~3. |
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