1 to 100 kHz/20-200A AC Current Probe for Measuring Inverter Equipment and Other Low Frequency Devices. Hioki current sensors are best-in-class devices for use with power meters, Memory HiCorders and high performance oscilloscopes. The 9272-10/9272-05 are a 1 to 100 kHz AC current sensor ideal for measuring low frequency equipment such as inverters.