Hioki AC Clamp Meter CM4141 and CM4142

■ Development Background

Regular maintenance and management are essential in order to keep electrical equipment operating properly in buildings and manufacturing plants.  Clamp meters make it easy to measure current simply by clamping the jaws of the instrument around the cable being measured, and as a result they have entered into wide use in maintenance management applications.
Distribution panels have been shrinking in recent years, with the result that the wires inside them are packed closer together. Less space between adjacent cables makes it harder for technicians to do their jobs.
In addition, separately available flexible sensors can be used to measure thick, high-current cables but must be affixed to the clamp meter in order to do so. Such sensors are bendable, loop-shaped devices that are used by routing one end around the cable to be measured and back to the instrument, posing the risk of contact with energized terminals inside distribution panels.
By improving the shape of their sensors’ jaws, Hioki was able to design the new clamp meters so that they can be more safely and easily routed around thick, high-current cables.

■ CM4141, CM4142 Features


1. New, thinner jaw profile that can be more easily inserted into narrow spaces between cables and clamped around thick cables
Hioki reduced the width of the jaws near the opening to 11 mm to make the instrument easier to clamp around wires (jaw thickness at the same position ranged from 15 mm to 22 mm in previous products).
In addition, whereas the CM3289, which was launched last year with a design that is easier to clamp, can measure cables with a diameter of about 33 mm, the CM4141 and CM4142 can measure cables with a diameter of up to 55 mm, providing the ability to measure even thick cables without needing to connect a flexible sensor.


2. Robust jaws that are strong enough to push and pull wires
Sometimes the jaws have to be pried into place when a large number of cables are packed into a small space. Despite their thin dimensions, the CM4141 and CM4142’s jaws are strong enough to withstand being maneuvered into place.


3. Measure up to 2000 A AC using the true RMS method
The CM4141/CM4142 delivers accurate results even when measuring AC current waveforms that have been distorted by a device such as an inverter or switching power supply.  Whereas the previous model was able to measure currents of up to 1000 A AC, the new models can measure up to 2000 A AC. Since they offer three ranges (60.00 A, 600.0 A, and 2000 A), they can be used in a variety of applications.


4. Significantly reduced workload thanks to a weight of just 300 g
The CM4141/CM4142 is more than 100 g lighter than a conventional clamp meter of the same size. As a result, the load on the hand when holding the instrument for an extended period of time has been significantly reduced.








5. Extensive measurement functionality
The CM4141/CM4142 can measure multiple parameters, including AC current, AC/DC voltage, frequency, continuity, resistance, capacitance, diode, and temperature.


6. Bluetooth® wireless technology (CM4142 only)
HIOKI’s free smartphone app GENNECT Cross can be used to transfer measured values from the CM4142 to a smartphone. In addition to creating simple reports (in PDF format), the app can save data as a CSV file for later editing in Excel.


■ Principal applications and locations of use
• Verifying whether circuit breakers’ current ratings are appropriate
• Verifying the starting current (inrush current) of electrical equipment and conducting maintenance inspections
• Carrying out electrical work, building maintenance, plant maintenance, etc.


■ Series Lineup
AC Clamp Meter CM4141
AC Clamp Meter CM4142  (with Bluetooth® wireless communication)