Current sensor units can be used for large-current power measurements, which are difficult to take directly in excess of a power meters rating. With the ability to measure a wide range of frequencies from DC to 100 kHz with high precision, these can be used in a variety of power measurement applications, such as EV/ inverter drive motors and fuel cells. In addition, they can be calibrated when used in combination with Yokogawa's WT Series of digital power meters or PZ4000 power analyzer. This makes them well-suited to power measurement applications requiring an especially high level of precision. (However, only a limited number of points can be calibrated.) Use model 751521 for single-phase measurements and model 751523 for three-phase measurements.