Development Of Multi-function And High-precision Resistance Tester

Loop resistance testers,transformer's DC resistance testers,and earth-continuity testers are widely used in the testing of the electrical facilities and equipment.The precision of these three micro-resistance testers is highly-important in detecting the power grid status.Also,it helps detecting the potential failures of the facilities as well as launching the maintenance.Therefore,the calibration of testers must be carried out every year.According to the requirements of the verification regulations,thes e three testers share some verification-events.The paper is mainly study on the commonness of the loop resistance testers,transformer winding DC resistance testers and earth-continuity testers,as well as put forward a multi-function resistance calibration tester based on a current-mode active analog resistance.The tester is cored with a 32-bits microprocessor,using the technology of high-current measurement and the technology of precise simulation,along with the precise resistance,signal modulator,DA amplifiers and other high linearity components,to simulate a high-power resistance.The calibration tester has the advantages of high linearity,high precision,low cost,easily operated and so on.Finally,establishing an internal verification regulation for Shantou power supply bureau,and calibrating the loop resistance testers,transformer's DC resistance testers,and earth-continuity testers on a regular basis.The tester is guaranteeing the precision of the date and the safety-operation of the power grid.In the same time,it also helps reducing the cost of tester calibration.