The on-load tap changer is the only moving part connected with the transformer circuit so more and more attention has been paid to the detection of the on-load tap changer.In the electrical equipment handover and preventive test regulations it is required to check the action sequence of on-load tap changer measure switching time etc.This device is mainly used for measuring the transition waveform transition time transient resistance of transformer on-load tap changer three-phase synchronism etc. product names On - load tap - changer tester transformer on - load tap - changer tester transformer on - load switch tester