The Fluke 355 digital clamp-meter is a true RMS sensing, auto-ranging multimeter for measuring current, voltage, frequency, and resistance in electrical testing applications. It has a clamp that measures AC (alternating current) and DC (direct current) to 2,000A (amperes) (1,400A AC RMS). The clamp has two jaws that can close around an electrical conductor up to 58mm (2.3 inches) in diameter to measure the current of large or multiple conductors without touching or interrupting the circuit. A set of test leads is included for measuring AC voltage to 600V, DC voltage to 1,000V, frequency to 1kHz (kilohertz), and resistance to 400kΩ (kilohms). The test leads are silicone-insulated for flexibility and resistance to heat and cold. The meter has a rotary switch to select the property to measure, and an LCD with a backlight for visibility in low light that turns off automatically after five minutes.

The meter's inrush current function analyzes the surge current at the startup of motors and other inductive loads to provide accurate, stable measurements. It features a low-pass filter that reduces high-frequency interference to allow accurate measurements of complex wave shapes. The minimum/maximum function toggles to display the lowest, highest, and average readings. To aid documentation of readings and capture readings in tight spaces, the data hold function keeps the reading on the display after disconnecting from the circuit. A continuity buzzer confirms that the circuit conducts electricity. The unit operates on six 1.5V AA batteries, and turns off automatically after 20 minutes of non-use to conserve battery life. It has a low-battery indicator that signals when the battery needs to be replaced.

This true RMS (root mean square) sensing meter provides accurate readings when measuring linear or non-linear loads, regardless of waveform. It is auto-ranging, so it automatically selects the appropriate operating range for the property being