Radon Exhalation Rate Meter Software

The measurement of radon exhalation rate is the important mean of looking forthe polluted source in prevention and governance of radon pollution. However, thereare some problems in the existing instruments and methods for measuring radonexhalation, for sampling, the time of sample is too long, and the factors such as theleaks affecting the measurement results aren’t amended. So the results of themeasurement are unstable, and the accuracy is also relatively poor. A measuringinstrument is being developed, according to the above reasons. The instrument canmeasure the radon exhalation rate from medium surface fast and reliably. The theorymodel of the instrument is an invention patent named “The measurement method andapparatus of radon exhalation rate from medium surface”，Which is invented byGuizhi Zhao, Detao Xiao etc. of the University of South China. The software isdesigned, which is based on the hardware of the instrument for measuring exhalationrate. And the performance of the software is tested in radon laboratory of theUniversity of South China.The software of instrument for measuring radon exhalation rate is consisted of8parts: the main program module, human-computer interaction module, settingparameter module, counting and timing module, measuring temperature and humiditymodule, clock module, processing data module and data management module. Themenu of human-computer interaction is displayed by multi-level menu, and theprogram is designed by structure mode. The human-computer interaction button isdebounced with flag-bit. The setting of cycle, clock, the data number of the query anddelete are realized in setting parameter module. External interrupts are used incounting and timing module. Temperature and humidity are monitored with theDHT11temperature and humidity sensor in measuring temperature and humiditymodule. The time of the measurement data is recorded with DS12C887real-timeclock chip in Clock module. Temperature and humidity correcting factor is used to correct the measurement results in processing data module, because the influencecaused by temperature and humidity for the collection efficiency is considered; theiterative correcting factor is introduced to modify the measurement results, becausethe impact of the218Po particles not decayed for the measurement result of the nextcycle is considered too. The protection for data of power-down, inquiring data anddelete data are implemented with the EEPROM memory of STC microcontroller indata management module.The performance of the software is tested in radon laboratory of the Universityof South China to verify the overall performance of instrument for measuring radonexhalation rate. The experiments show that the instrument for measuring radonexhalation rate has a stable performance, and can obtain an accuracy data frommeasurement. The software design of the instrument for measuring radon exhalationrate is practical and reasonable. The instrument for measuring radon exhalation rate iseasy to promote in the domestic.