The Designe And Research Of Scaler Which Can Automatic Obtain Radon Concentration Value Based On FPGA

In the process of radon concentration measurement in the scintillation chamber method, the FD-125 radon thorium analyzer is usually used with the domestic traditional scaler. If using the traditional domestic scaler to time and count, single-function reset, start, the experimental operation need to record data at any time in completing a cycle count; and after completed the measurement to processing data, converting the count to radon concentration. It is inconvenient in operation, and automatic and intelligent level is not high.This paper designed a smart scaler just for converting the count to radon concentration,which can used with FD-125 radon thorium analyzer. The goal of the scaler design is: automation and intelligent are superior to the domestic traditional scaler. In the process of measuring radon concentration with scintillation chamber method, the instrument can replace the traditional scaler, such as FH463 scaler.The whole measurement system consists of two parts: hardware and software. In this paper, the hardware part mainly composed of signal processing circuit, high voltage and low voltage circuit, FPGA peripheral hardware circuit, gives the detailed schematic circuit diagram and makes the corresponding PCB, completed the debugging of the circuit.Software part mainly includes the lower computer and the upper computer two parts, the counting system control program of the lower computer is under the environment of the Quartus II software written in Verilog HDL,the method of top-down design is adopted during the design process, completed the function of FPGA in module, this paper gives the program source code of completing corresponding operation instruction, and explains the various modules, used the modelsim software simulation to verificate its function. PC interface designed by VB(Visual Basic), we also give the total control interface of host computer and a detailed description on its main controls, and gives the interface of the operation process, the FPGA communicate with PC through RS232. Finally, we have tested the power supply module, signal processing module and FPGA module, the test procedure and test results are also given. Test results show that the system software and hardware comply with the design requirements, the design plan is reasonable and reliable.