What’s special about HIOKI’s AC Leakage Current Clamps?
No matter if they are based on hall-sensor or zero-fluxgate technology: HIOKI is famous for their high-end AC/DC current sensors – and they have been for many years. Given that history and experience, it is not surprising that HIOKI also offers a large variety of clamp meters, including three AC leakage current clamps.
Before going into the details of what makes each of these leakage current clamps special, let's look at what they all have in common:
- They all measure based on the TrueRMS principle
- All of them can of course not only measure AC leakage and differential currents but also AC load currents
- Bluetooth functionality can be added to all of them with HIOKI's universal Bluetooth transceiver Z3210, allowing the clamps to communicate with smartphones and tablets running HIOKI's free "Gennect Cross" app
- HIOKI's clamp meters are not only designed in Japan, but they are also made in HIOKI's own factories in Japan's Nagano prefecture
So let’s look at the differences of these clamps. The above image shows HIOKI's CM4001 leakage current clamp. With a height of just 16 cm from top to bottom and jaws that have been engineered to make them as narrow as possible, you can use them even in the most confined spaces while still measuring on cables which are up to 24 mm in diameter. Should it become too inconvenient to read the white backlight and crispy clear display, then an optional Bluetooth transmitter (Z3210) allows you to read (and of course also store) the measurement values on your smartphone.
The smallest of the 5 current ranges is 60 mA, with a guaranteed accuracy for values from 0.6 mA. The largest current range of the CM4001 is 600 A, the frequency band is from 40 Hz to 1 kHz and the measurement category is CAT III 300V. Even though the current clamp is so small, it is packed with functions like auto-hold, min/max/average, or an inrush current measurement feature. The CM4001 has been designed to be a small yet powerful and universal leakage current clamp, made to be used in small and confined spaces and requiring little room in your toolbox.
Measuring 23.3 cm from top to bottom, the CM4002 leakage current clamp is not only more than 7 cm taller than the CM4001, it is also bigger in width and depth. This is because the CM4002 has been designed to provide the most accurate measurement results while allowing it to be used on cables with a diameter of up to 40 mm.
As a result, the smallest of 6 current ranges of the CM4002 is just 6 mA with a guaranteed accuracy for values from 0.06 mA, while the largest current range is 200 A. The frequency band is also wider than that of its little brother, ranging from 15 Hz to 2 kHz, and the CM4002 complies to the IEC/EN 61557-13 standard which defines requirements for current clamps for measuring leakage currents in electrical installations, such as the protection against external magnetic fields (Class 2, magnetic fields ≤30A/m is what the CM4002 fulfils).
The third of the three leakage current clamp siblings from HIOKI is the CM4003. Comparing the CM4002 with the CM4003 side-by-side, it is not easy to spot the differences between them. The physical dimensions are the same, and so are almost all technical specifications. It is easier to see the differences when comparing the two clamps side-by-side from a different view:
The connector at the bottom of the CM4003 allows for a special adapter cable to be connected to the meter. This adapter cable converts the 4-pin outlet of the CM4003 to these two connectors:
- A standard USB-C socket like the ones you find in most smartphones nowadays. It allows you to power the CM4003 externally in case you want to perform longer term measurements. The power can come from an optionally available HIOKI power supply unit, but nothing stops you from using any powerbank you would use to charge your smartphone.
- A standard (male) BNC connector allows to output the measured current as a voltage which you can feed it into a memory recorder like HIOKI's MR8870
The external connector of the CM4003 does impact its measurement category rating, which is CAT III 300V. In comparison, the CM4002 without the connector has a rating CAT IV 300V / CAT III 600V.
All three HIOKI CM400x leakage current clamps are available as bundle versions which have the Z3210 Bluetooth transmitter already included. These bundles are named CM400x-90.
The adapter cable for the CM4003 leakage current clamp is called L9097 and it is included with every CM4003. The external USB power supply (Z1013) as well as the required USB-A-to-USB-C cable (L9510) are optional accessories. But again, the external power connector is a standard USB-C socket.
All three HIOKI CM400x leakage current clamps are available as bundle versions which have the Z3210 Bluetooth transmitter already included. These bundles are named CM400x-90.
So, whether you are looking for a small yet powerful AC leakage (and of course also load) current clamp like the CM4001, or whether you prefer an AC leakage current clamp with superb technical specifications or even an external output of the measured current - HIOKI's CM400x series will cover your needs.
Z3210
HIOKI Z3210 - Bluetooth Adapter for compatible HIOKI Instruments
Wireless Bluetooth adapter for compatible HIOKI instruments enabling remote data transfer and mobile measurement documentation. HIOKI Z3210 available now.
CM4001
HIOKI CM4001 - Compact AC Leakage Clamp Meter with True RMS measurement, up to 600 A
Compact AC leakage clamp meter with True RMS measurement up to 600 A for precise leakage and load current testing. HIOKI CM4001 available now from HIOKI Europe.
CM4003
HIOKI CM4003 - AC Leakage Clamp Meter
True RMS AC leakage clamp meter for conductors up to Ø 40 mm, featuring waveform/RMS output and Bluetooth®-ready interface. Order online now at HIOKI Europe.
CM4002
HIOKI CM4002 - AC Leakage Clamp Meter
True RMS AC leakage clamp meter with 6 mA–200 A range and 15 Hz–2 kHz frequency band, fits conductors up to Ø 40 mm – ideal for industrial and service use. Order online now.
MR8870-20
MR8870-20 - Handheld 2-channel memory recorder with RMS data logging, 1 MS/s
Key Specifications2 isolated analog channels with BNC inputs 1 MS/s sampling rate, 12 bit resolution, DC to 50 kHz bandwidth RMS data logging with up to 1000 values per second Voltage measurement: 100 mV to 500 V, 12 ranges2 MWords internal memory per channel, removable memory card storage Typical ApplicationsCapture voltage drops, spikes, and transient power issuesDetect short voltage or current deviations over long periods using RMS logging Record inrush currents and motor control timing Diagnose PLC, relay, and control signal behavior Detailed Product OverviewThe MR8870 Memory Recorder is a compact, handheld data acquisition system designed for
technicians and engineers who require high-speed, isolated waveform capture in the field.
When configured as an RMS Recorder, the MR8870 calculates up to 1000 RMS values per
second, allowing short voltage or current deviations to be detected even during extended
monitoring. Equipped with two isolated analog channels with BNC inputs and four logic channels, the
MR8870 enables simultaneous measurement of analog waveforms and digital signals. Each
analog input supports direct voltage measurement up to 400 VDC and is isolated from earth
up to 300 VAC/DC in CAT II environments.Waveform recording and RMS loggingThe MR8870 records waveforms with a maximum sampling rate of 1 MS/s, 12-bit vertical
resolution and a bandwidth of DC to 50 kHz. Configurable trigger functions with adjustable
pre-trigger settings allow event-based recording aligned with the measurement task, for
example when capturing voltage or current transients, inrush currents or relay dropouts. When configured as an RMS Recorder, the MR8870 calculates up to 1000 RMS values per
second based on high resolution sampling. This enables detection of short duration voltage
or current deviations during extended monitoring periods without averaging them out. RMS
values can be stored at user defined intervals together with minimum and maximum values
for each interval. Current measurement with external sensors
The MR8870 also measures current using external current clamps or sensors with a voltage
output. AC current clamps with BNC connectors can be connected directly to the MR8870's
analog inputs for portable industrial measurements. Compatible HIOKI Rogowski sensors
support current measurements up to 5000 A, depending on the selected sensor. For higher accuracy or DC current applications, compatible current sensors with ME15W
connectors can be used in combination with an external sensor unit for sensor power supply.
The measurable current range and frequency response are defined by the selected external
sensor, while the overall system bandwidth of the MR8870 is DC to 50 kHz. Logic inputs and probes
The MR8870 provides four logic input channels for simultaneous recording of digital signals
with analog waveforms. The logic inputs can also be used as trigger source or for time
correlation of switching states with measured voltage and current signals. For low-voltage digital and contact signals, the Logic probe 9320-01 supports detection up to
50 V DC, including PLC outputs and open-collector signals, with pulse detection down to 500
ns. For relay drive and mains-level signals, the isolated Logic probe MR9321-01 enables
detection of AC or DC signals up to 250 V and can be used for monitoring contactors, relay
coils or power line interruptions.Memory, data handling and power supply
The MR8870 provides 2 MWords of internal memory per channel for event-based waveform
recording at the maximum sampling rate. For extended measurements or continuous
logging, data can be stored on a removable memory card. When connected to a PC via USB,
the MR8870 appears as a removable drive, providing direct access to files stored on the
memory card. Recorded data can be analyzed using compatible software including the
Dedicated Wave Processor Program for the 8870-20, WaveViewer or the 9335 Wave
Processor. The compact housing weighs approximately 600 g and is designed for handheld use in field
environments. The MR8870 can be powered using the included Z1005 AC adapter, an
external DC supply or an optional battery pack. Battery operation enables up to two hours of
autonomous measurement. The MR8870 is manufactured in Japan.
Z1013
Z1013 - Power supply unit for Hioki SP3000 and SP7150
Das HIOKI Z1013 ist ein Zubehörnetzteil für HIOKI CM4003, SP3000, SP7001-95, SP7150.
CM4001-90
HIOKI CM4001-90 - AC Leakage Clamp Meter, Bluetooth
Compact Bluetooth®-ready leakage clamp meter (0.60 mA-600 A) with slim φ24 mm jaws for tight spaces. Industrial & service-ready. Order online at HIOKI Europe.
CM4003-90
HIOKI CM4003-90 - AC Leakage Clamp Meter, Bluetooth
Advanced True RMS model with Bluetooth® module for compact conductor measurement up to Ø 40 mm, range 6 mA–200 A, ideal for industrial diagnostics. Order now at HIOKI Europe.
CM4002-90
CM4002-90 - AC Leakage Clamp Meter, Bluetooth
The CM4002-90 is a True RMS AC leakage meter with a measuring range of 6mA to 200A and a frequency range of 15 to 2000 Hz. Designed to cover conductors up to 40 mm in diameter, the CM4002 offers a range of advanced functions including Max/Min/AVG/PEAK MAX/PEAK MIN value display, display hold and auto-hold, backlight, automatic power-saving mode, acoustic signal (buzzer), event display, comparator, simple event recording, and inrush current measurement.The CM4002-90 is equipped with the Z3210 module for wireless data transmission via Bluetooth. Technical Details: Measuring range: 6 mA to 200 A Frequency range: 15 to 2000 Hz Cable diameter: Up to 40 mm Key functions: Max/Min/AVG/PEAK MAX/PEAK MIN, display hold, auto-hold, backlight, automatic power-saving mode, buzzer, event display, comparator, simple event recording, inrush current measurement Wireless data transmission: Via Bluetooth with Z3210 moduleLearn more in our blog What’s special about HIOKI’s AC Leakage Current Clamps?