Large Jaw Lets You Clamp with Ease, ‌Measure thick cables right at the terminal

Hioki clamp meters are best-in-class measuring devices incorporating Hioki’s expertise in current sensing technology. The CM3291 is a true RMS rectified 2000 A AC clamp meter that features a broad operating temperature range of -25°C to 65°C, thin and compact clamp core and optional flexible current sensor that you can attach to let you get into the tightest spots.

CAT IV 300 V, CAT III 600 V

Get into tight spaces even with large jaw

The new AC Clamp Meter CM3291 features a new and innovative jaw design that lets you get between narrow cable gaps despite the large jaw offering, improving work efficiency at the worksite. The compact meter delivers a wide measurement range from a few amperes up to 2000 A.

Key Features

  • AC only, measure up to 2000 A AC
  • -25°C to 65°C operating temperature range
  • Also measure resistance, continuity, AC and DC voltage

Model No. (Order Code)

CM3291 True RMS

True RMS measurement delivers accurate results for even distorted waveforms.

The waveform including harmonic components is calculated according to an RMS calculation formula and displayed.
True RMS measurement yields accurate display values even when measuring a distorted waveform, for example from an inverter-equipped device or switching power supply.

A pocket clamp meter that can use flexible sensors

When connected to an optional flexible current sensor*, the CM3291 can be used to measure the current flowing in pairs of wires or in tangled or complexly routed wires around which it was not possible to apply a clamp-on sensor in the past.


Essential for electrical work: A thin card tester that fits in the pocket with all the capabilities of a clamp meter

The CM3291 delivers all the functionality of a clamp meter and card tester in the form factor of the latter. In addition to current measurement, this single instrument delivers voltage measurement, continuity check, and resistance measurement functionality.

Rugged, portable design that’s drop-resistant

Despite its thin, compact design, the CM3291 has an operating temperature range of -25°C to 65°C and can withstand being dropped from a height of 1 m onto concrete. It’s engineered for use in tough environments.

Comes with a sturdy and lightweight hard case

All accessories can be stored.

Basic specifications

Accuracy guaranteed: 1 year
AC Current range 42.00 to 2000 A, 3 ranges (40 Hz to 1 kHz, True RMS),
Basic accuracy 45-66 Hz: ±1.5% rdg. ±5 dgt.
DC Voltage range 420.0 mV to 600 V, 5 ranges, Basic accuracy: ±1.0 % rdg. ±3 dgt. (at 4.2 V range)
AC Voltage range 4.200 V to 600 V, 4 ranges (45 to 500 Hz, True RMS),
Basic accuracy 45-66 Hz: ±1.8% rdg. ±7 dgt. (at 4.2 V range)
Crest factor For 2500 counts or less, 2.5 Reduces linearly to 1.5 or less at 4200 counts But, 1.5 or less for 2000 A ACA range
Resistance range 420.0 Ω to 42.00 MΩ, 6 ranges, Basic accuracy: ±2.0 % rdg. ±4 dgt. (at 420 Ω range)
Other functions Continuity check: Buzzer sounds at 50 Ω ±40 Ω or less, Data hold, Auto power save, Drop-proof from height of 1 meter
Power supply Coin type lithium battery (CR2032) ×1, Continuous use 70 hours
Core jaw diameter φ 46 mm (1.81 in), Jaw dimension: 65 mm (2.56 in) W × 13 mm (0.51 in) D
Dimensions and mass 57 mm (2.24 in) W × 198 mm (7.80 in) H × 16 mm (0.63 in) D, 103 g (3.6 oz)
Included accessories Carrying case ×1, TEST LEAD L9208 ×1, Coin type lithium battery CR2032 (for trial purposes only) ×1, Instruction manual ×1, Download guide ×1, Operating precautions ×1

CT6280 Basic specifications (Accuracy guaranteed for 1 year, Post-adjustment accuracy guaranteed for 1 year)

Core jaw dia. φ 130 mm (5.12 in) (Cable cross-section diameter: 5 mm (0.20 in); tip cap diameter: 7 mm (0.28 in))
AC Current 419.9 A/ 4199 A, 2 ranges (±3.0 % rdg. ±5 dgt.)
Cable length 800 mm (31.5 in)

Included Accessories (1)

The Carrying Case (accessory) is a hard type, 222 mm (8.74 in)W × 115 mm (4.53 in)H × 46mm (1.81 in)D

Options (3)

L4933, L4934: Attach L9208 with the cap removed

Related Products