Removing the shackles from meter test equipment

Transformers have influenced the design of testing equipment for over 100 years. During this time the restrictions imposed on us by transformers have become an accepted limitation on the performance of testing equipment and this in turn has influenced both testing methods and the structure of testing organisations. Other techniques now exist enabling transformer-less circuits to be used which deliver higher performance in practice and allow a more flexible approach towards testing. Moreover, new technologies in metering and in the metering environment are placing new demands on testing equipment, while influences such as privatisation are introducing a more flexible approach. In order to evaluate these trends, we examine the restrictions imposed by transformers, the techniques involved which can replace transformers, the improvements in the performance and design of transformer-less meter test equipment and the possible impact on the testing of meters and peripheral devices in the future