Amprobe ACD-51NAV [3729950] CAT IV 600A True-rms Navigator™ Clamp Meter. The Amprobe ACD-51NAV is a versatile clamp-on power meter that offers a full range of diagnostics, including those that HVAC technicians need most — volts, amps, resistance, capacitance, DC microamps, in-rush current and temperature. The Amprobe ACD51NAV Measures AC/DC voltage to 1000V, AC current to 600A, plus resistance, frequency, capacitance, power factor, total harmonics distortion (THD) and individual harmonics from 1 to 25. Other features include inrush current measurement and phase rotation indication for 3-phase motors, a Non-contact voltage detection which enhances safety, continuity bepper, min max and smart data hold, an In-jaw flashlight automatically lights when jaws open to illuminate dark panels and junction boxes, and a Large backlit digital display with analog bar graph presents the full picture. The ACD-51NAV is a great clamp-on multimeter choice for troubleshooting or maintaining air conditioning or motor efficiency, measuring phase rotation, and identifying harmonics. Convenient joystick enables quick single-handed function selection.