Design And Implementation Of Program Controlled Earth Resistance Meter

With rapid development and wide application of various types of electronic instrument and equipment,to ensure the safety and accuracy of instrument and equipment,earth resistance measurement is on the increase.The traditional earth resistance measurement method is of low efficiency and the effect of artificial errors is unavoidable.Therefore,to achieve high precision and high efficiency measurement of earth resistance,it is necessary to develop a new type of earth resistance meter.By increasing the wired communication and wireless communication,programmed control is exercised over the traditional earth resistance to realize the automatic measurement of the earth resistance meter,reduce the number of earth resistance detecting personnel to achieve fast and efficient measurement,and solve the issue that the current earth resistance meter can't realize the programmed control.This thesis analyz the current demand on earth resistance measurement,studied the principles of earth resistance measurement,pulsating voltage source technology,pulse signal measurement technology,etc.On this basis,the error sources of the traditional earth resistance meter were analyzed,and the accuracy of the ground ohmmeter was improved by using the higher linearity ADC and the calibration technology.The current measurement procedure was optimized by increasing the measurement functions of the handheld wireless terminal and automatic testing software,and reducing the measurement workload of earth resistance;the structure of the earth resistance meter was optimized,and the anti-jamming performance of the earth resistance meter was improved;the miniaturization design and low power design were carried out for the system to reduce the static power consumption.In addition,the sources of the earth resistance meter's uncertainty were analyzed,and a mathematical model was established to evaluate the standard uncertainty and increase the reliability of the measurement results.The main work of the thesis was as follows:(1)completing the design of pulsating voltage source,resistance measurement circuit,data wireless communication circuit,etc;(2)optimizing the hardware and software anti-jamming design for the program-controlled earth resistance meter;(3)developing an automatic test software for the earth resistance meter to achieve the automatic control of the earth resistance meter;(4)verifying the function and performance of the program-controlled earth resistance meter.Program-controlled earth resistance meters,simple in structure and powerful in function,adopt digital measurement technology and wireless communication technology,and use simple operation to replace the traditional measurement work.Therefore,they meet the increasing demand on earth resistance measurement,and have a good practical application prospect.