The AEMC 407 digital clamp-meter is a true RMS sensing, auto-ranging multimeter for measuring current, voltage, frequency, resistance, and power in electrical testing applications. It has a clamp that measures AC (alternating current) to 1,000A (ampere) and DC (direct current) to 1,500A. The clamp has two jaws that can close around an electrical conductor up to 48mm (1.89 inches) in diameter to measure current without touching or interrupting the circuit. A set of test leads, which are silicone-insulated for flexibility and resistance to heat and cold, is included for measuring AC and DC voltage to 1,000V, frequency to 20kHz (kilohertz), and resistance to 100kΩ (kilohms). For power monitoring and analysis, the meter measures THD (total harmonic distortion) which can degrade the quality of the power being supplied by the system, analyzes individual harmonics to the 25th order, calculates power factor to determine how efficiently an installation uses power, and measures single- and three phase real power to 3,000kW (kilowatts), reactive power to 1,500 kilovar (kilovolt-ampere reactive), and apparent power to 1,500kVA (kilovolt-ampere).

The meter has a rotary switch to select the property to measure, and a three-line 10,000-count LCD with a backlight for visibility in low light that turns off automatically after two minutes. For data logging and analysis, the meter has a data recording function that allows storage of up to 1,000 measurements, comes with a wireless adapter for communicating with a PC, and includes DataView software for downloading measurements from the meter to generate reports. The software is compatible with Microsoft Windows XP, Windows Vista, Windows 7, and Windows 8 with support for 32- and 64-bit systems. The data storage rate is programmable from one reading per second to one reading every 600 seconds. The inrush current function, with a selectable sampling time of 1ms (millisecond) or 100ms, analyzes surge current at