The TRMS Clamp-On Leakage Current Meter Model 566 is designed to measure low AC currents, which are typically leakage currents in ground conductors. Low currents are measured in the 60mA and 600mA ranges. The high sensitivity of the probe (1µA, 10µA, and 100µA) resolution when measuring mA is possible through special jaw construction and, in particular, critical shielding of the jaws. At low measurement levels, shielding out noise is critical for low sensitivity, accuracy, and stability.

The Model 566 can be used as a standard clamp-on meter measuring to 60Arms, as well as VAC and VDC ranges, resistance, and continuity with a buzzer. In mAAC and AAC, the user can activate a low-pass filter (LPF) to ignore all currents other than 50/60Hz. In this mode, only the fundamental signal is measured.

The Model 566 is ergonomic in design and fits well in the hand, facilitating one hand operation. The jaw size is compact yet designed to accommodate the most common conductors up to 0.91" in diameter.