ZDYK-2000 transformer on-load switch Tester, is used for the measurement and analysis of power system in power transformers and special electrical performance of transformer on-load tap-changer integrated measuring instrument. It adopts microcomputer control, through the design of precise measuring circuit, can make the transition to on-load tap-changer transition time, waveforms, parameters such as resistance, three-phase period of accurate measurements. User may act according to needs and conditions, directly from the measuring tap lead, can also be measured by the transformer casing and neutral-point three-phase connection.