Abstract: The paper presents a review of several new devices for instrument transformer accuracy testing which are developed in the Electrical Engineering Institute "Nikola Tesla", Belgrade, Yugoslavia. Instrument transformer on-site accuracy testing device, type INST-2, based on the compensated current comparator method is described. Computer controlled device for the automatic testing of current transformer accuracy, type ASK-2, permits the automatic testing in the mass production of low voltage current instrument transformers with both good metrological characteristics and the excelent efficiency. Both hardware and software instrument improvements made in the computer based on device for precise laboratory accuracy tests of instrument transformers, type INST-2A, are pointed out.
Keywords: Transformer, testing, current comparator.