The Development Of Environmental γ Radiation Dose Rate Monitoring System

With the rapid economic development, the use of nuclear energy is increasingly widely. On the one hand nuclear energy benefit the humanity, on the other hand it also brings security risks because of its radiation. Once the nuclear material or nuclear waste leak occurs, the consequences would be too ghastly to contemplate. Theγradiation dose rate can reflect the nuclear radiation levels in the environment very well, but the environmentγmonitoring instruments that can meet the requirement of real-time measurement are very few. And network monitoring system for remote monitoring are even fewer. This environmentalγradiation dose rate monitoring system not only measure theγdose rate with real-time, but also it can send the survey result to client computer to view through serial port, in particular, it can send the measurements to Server to display through Network. So that users can know theγdose rate of the monitor sites at any time, once theγdose rate over the safe rang, they can always take measures to ensure the safety of the people round the monitoring sites. Radiation dose rate monitoring system consists of the following components:1.γdetector(referred to as the probe) and voltage follower and shaping circuit. The circuit transforms theγ-ray into voltage pulses that can be computed. The detector consists of Geiger-Muller counter and power circuit. The subject chose a transistor 2N3904 and 74HC221 to design the voltage follower and shaping circuit.2. MCU processing circuit. This circuit mainly completes the functions: parameter setting, measuring, counting, display, sending data and so on. The subject chose 78E58B SCM as core processor. Peripheral circuits including: key circuit, 8253 counting circuit, LCD display circuit, serial port circuit, clock circuit, buzzer circuit and so on.3. MCU program. The program is used to deal with the interrupt of buttons, read the measurement results and deal with the result to get theγdose, display theγdose in the monitor, control the port to receive and send the data and control the buzzer to sound to alarm.4. Host computer application software. This software is generated in C++ builder environment compiler. Programming language was C++ object-oriented language. This application software includes client application and server application. Client application software main functions are collecting the measurements of lower computer through serial ports and display the data to the main interface. Server application software main functions are sending order to client computers and receiving the measurements from client computers through the remote monitoring function. So, the server will be able to monitor all clients, and then monitor the measurements of monitoring site of clients.γradiation dose rate monitoring system has been tested and meet the design requirements. The circuit work stably and the measurement data is accurate. The application software function stably and the collection data is accurate.