The Research Of Air-kerma Automation Standard Device At Protection Level Gamma Rays

It’s known that the gamma rays is a kind of strong electromagnetic wave whichwavelength is short, since found, it was widely used in scientific research, industry,agriculture, environmental protection and other fields. While gamma radiationproblems are great harmful to human being and natural environment. In order tomeasure the radiation dose, people developed various radiation measuring instruments.To ensure the measuring instruments of the gamma value is accurate and the safety ofthe professional staff, we must implement the gamma dose quantity traceableguarantee the quality of measuring instruments. As the basis of quantity traceability,an accurate and reliable gamma-ray device not only has practical values but also haseconomic values. It is an important work for benchmark lab to set up.The thesis mainly Bases on "protection level gamma ray Air-Kerma automationstandard device design" and introduces three effect in radioactive fields, compares thedomestic gamma rays standard device with the abroad,then putting forward thedesign method of hardware and software standard device radiation field systems. Wealso puts the image recognition technology to obtain the measuring instruments digitalreadings, successfully achieves the digital display of instruments in automatic..Protection level of gamma-ray standard device is consisted of a controlled unitbased on computer, environmental parameters measuring unit, positioning system,gamma radioactive sources and damping unit, display unit, the safety instructionsmodule, etc.The Gamma radioactive sources and the damping devices included the selectionand control of radioactive sources, and the double selector. Positioning system,included the stepper motor driver X axis, Y axis and Z axis guide control module,rotating test platform, used a laser device accurate positioning waiting forinspection/calibration instrument of test points. Dose parameters and safetyinstructions of control module, including dose parameters calculation, Yon-tai inlaboratory using belt of high resolution CCD video monitoring, as well as the source, the exit of state monitoring, real-time transmit data to the host for processing.While for Computer controlled measurement unit, the major interface of the PCis to send control instruction for motor driven and cylinder, at the same time, thechoice of Double frequency selector，environmental parameters, and guide the testplatform of the accurate position. The dose parameters are obtained by polynomialfitting formula. In the thesis we put forward to make the image recognitiontechnology applied in the reading inspected said several digital instrument creatively.In order to verify the Built standard device, we have some index to test, such asthe outdoor dose rate source measurement evaluation, inverse square law ofexperiment, the radiation beam uniformity, scattering effect measurement experiment,according to the measured data, we calculate the repeatability and uncertainty for thestandard device, the results showed that the standard equipment of various technicalindicators meet the national standards requirements.