Fluke a clip-on current transformer. Measuring range selectable per software: 0.01 A to 1 A and 0.1 A to 10 A. Peak current for sinusoidal currents: 3.7 A and 37 A. Intrinsic error: 0.5 percent. Frequency range: 40 Hz to 10 kHz. Operating voltage: 300 V CAT IV. Phase error: 0.5 degree. Jaw opening: less-than 15-millimeters diameter or 15-millimeters by 17-millimeters bus bars.