Smarter sensors and transducers are required in the new smart grid scenario with increased performances, in terms of high accuracy and wide frequency bandwidth. Traditional calibration systems, developed for conventional instrument transformers are not suitable for performance verification of the new types of non-conventional instrument transformers, both in terms of input range and frequency bandwidth. Therefore, a new industrial comparator for smart grid sensor calibration is presented in this paper, which is intended for the calibration of conventional and non-conventional voltage and current instrument transformers, in a frequency range from dc to tens of kilohertz. Its accuracy performances allow for the calibration, in sinusoidal and non-sinusoidal conditions, of class 0.1 sensors.