System Design And Testing For Automatic Measurement Of Resistor Load Coefficient

In the past twenty years,with the development of precise instruments and the rise of the industrial production,the resistance measurement accuracy put forward more and more high demand.Due to the temperature change from the resistor's self-heating with current,the value of the resistor will also change,which is called load effect,In the field of metrology,the resistor load effect become an important factor of affect the resistance valu.This topic proposed a resistor load coefficient automatic measurement system based on direct current comparator?DCC?,the main work is as follows:1.The resistor load effect evaluation theory is researched,derived its calculation method using the least squares principle of the resistor load coefficient.Based on DCC,measured method of the resistor load coefficient is raised and the related system is developed.2.Test system including dc current comparator,constant temperature of the tank,scanning switch,computer and low load coefficient precision resistor.The resistor load coefficient measurement system is developed based on the Lab VIEW software platform,automatic measurement,data analysis,data storage and other functions are realized about the resistor load coefficient,it provides software support further popularization and application for the resistor load coefficient calibration system.3.Based on this system,it proceed a large number of experiments.After the test,measuring relative error minimum is-2.29×10^-8 for the resistor load coefficient measurement system based on DCC.Self-calibration of the low load coefficient precision resistor gets-9.47×10^-9.A group of used in portable low load resistor in the air are made relative to used in the oil,The value of resistance are 1?,10?,100?,1 k?,10 k?.After the test,resistor load coefficient gets 10^-610^-8.For the two types of load,a set of application verification test are completed based on the low load resistor measurement system,confirmed that this system can be put into used in the resistor load effect verification work.Comprehensive resistor load coefficient value of the tes t,the resistor load coefficient measurement system calibration accuracy up to 10^-8magnitude by this topic.This system provides sampling resistor quantitative calibration scheme for the precision measuring instruments industry,so as to improve measurement accuracy for the current and electrical,it contributes to promote technology level of the scientific instruments industry.This set of device system has been in Fujian province institute of metrology and national institute of metrology,China.