Fluke 325 Clamp Multimeter 400A AC/DC True RMS measurement tool

Purpose-built clamp meter

The Fluke FLUKE-325 is a digital clamp multimeter designed for electricians and technicians who need to measure AC and DC current up to 400 amps without breaking the circuit. Its 30 mm jaw opening accommodates standard conductors while True RMS sensing ensures accuracy on both linear and non-linear loads. The meter also covers AC and DC voltage to 600.0 V, resistance to 40 kilohms, plus temperature, capacitance and frequency functions. An audible continuity sensor provides quick circuit verification.

Capacity and headroom

The 400 A current range handles typical residential and light-commercial panels, while the 600 V voltage rating suits most low-voltage distribution measurements. True RMS maintains stated accuracy of 2 % ± 5 digits even when waveforms are distorted by variable-speed drives or electronic ballasts. Resistance measurement tops out at 40 kilohms, so higher-value components require a different instrument. The jaw opening limits conductor size to 30 mm, restricting use on large busbars or bundled cables.

Safety standard limits

The meter meets IEC 61010-1 and carries CAT IV 300 V and CAT III 600 V ratings, defining the over-voltage transient protection at the point of measurement. These categories set the practical boundary for where the tool can be safely connected; measurements beyond those ratings demand a meter with higher category certification. The 2 % accuracy figure applies within the specified ranges and does not extend to signals outside the 400 A or 600 V limits.