Chauvin Arnoux F406 [P01120946] 1000A AC / 1500A DC TRMS Clamp Meter. The Chauvin Arnoux F406 has a high protection rating and is ideal for maintenance, testing, monitoring and diagnostics on medium-power installations. It has been developed with a fast 12-bit TRMS digital acquisition system and offers particularly accurate measurements whatever the signal's waveform.