HIOKI CM3289 AC Clamp Meter | AC 1000 A, true RMS, 8.3 mm jaw thickness, φ33 mm jaw, -25–65°C

HIOKI CM3289 True RMS AC Clamp Meter: 8.3mm Thin Jaw and 1000A AC Measurement

Overview

The HIOKI CM3289 is a high-accuracy AC clamp meter built for modern electrical environments. With inverter equipment and switching power supplies now widespread, its true RMS measurement accurately captures current waveforms distorted by harmonics. Continuing HIOKI's classic ultra-thin design, the CM3289 has a jaw thickness of 8.3mm and a jaw diameter of φ33mm, so it can clamp large conductors even in crowded distribution cabinets and deliver dependable readings.

Key Specifications

Accurate Measurement of Complex Waveforms

• True RMS: Provides accurate true current readings even for non-sinusoidal signals from inverters, energy-saving lighting or computer power supplies, avoiding the errors of average-responding meters.
• Wide 1000A AC range: Measures AC current up to 1000A, covering needs from infrastructure maintenance to industrial equipment inspection.

Fits Tight Spaces, Built to Last

• 8.3mm thin jaw: The 8.3mm jaw thickness makes it easy to reach between densely packed wires.
• Wide operating temperature, -25°C to 65°C: Highly tolerant of its environment, maintaining stable accuracy whether at cold outdoor sites or in hot machine rooms.
• 1 m drop test: A rugged, drop-resistant body built for demanding job sites.

Multi-Function Electrical Testing

• Comprehensive functions: In addition to current, it measures AC/DC voltage and resistance and performs continuity checks.
• Optional expansion: Compatible with the CT6280 flexible current sensor, extending measurement to very tight spots or large busbars.

Source

Specifications per the HIOKI product page and CM3289 catalog (retrieved 2026-10-20).