Product Feb. 10, 2022

Reliable power measurement with both convenience and high accuracy: HIOKI will release 5 models of clamp-type current sensors

Hioki releases clamp-type current sensors: AC/DC current probes CT6841A, CT6843A, CT6844A, CT6845A and CT6846A. The conventional feature of clamp-type current sensor has the convenience of measuring the current without having to disconnect the measuring cable. The new clamp-type current sensors combine this convenience with reliable and accurate measurements. These features enable the accurate power consumption measurement required by the WLTP test, (Worldwide harmonized Light Vehicles Test Procedure - the international fuel economy standards for automobiles).

AC/DC Current Probe
(From the left CT6845A, CT6846A, CT6841A, CT6843A, CT6844A)

Background of development

In recent years, highly accurate power measurements are required in the development of electric vehicles. Cables in an assembled electric vehicle cannot be cut for power measurement. The conventional clamp-type current sensors have the convenience of measuring the current without disconnecting the cable, but the accuracy of the measurement needs to be improved.
HIOKI has achieved both convenience and high accuracy based on its the clamp-type sensors developed since 1971. These 2 features, convenience and high accuracy are very effective for the high-precision power measurement of equipment where cables cannot be cut. These current sensors are useful for measuring the power of installed equipment such as power generation equipment, fast charging devices, and batteries.


1. Highly accurate DC current measurement

Measurement accuracy has been improved from ±0.3% to ±0.2%. Highly accurate DC current measurement has been achieved by improving the structure of mounting part of the clamp tip and the optimized design of the magnetic circuit.

2. No need for special setting for high accuracy measurement

Our high precision power meter “Power analyzer PW8001” can be connected to different types of current sensors depending on the measurement. In order to measure the power accurately, the current sensor must be set correctly. The new AC/DC current probes are automatically set up by simply connecting to the PW8001. The new AC/DC current probes transmit the internal recording information, such as model name, serial number, calibration data and provide much accurate power measurement than before. This function prevents incorrect measurement due to operator setting error and enables measurements to be taken immediately.

3. Improved basic performance

The new AC/DC current probes not only provide improved accuracy, but also improved frequency band performance. CT6841A, which has the widest bandwidth has succeeded in improving performance up to 2MHz. CT6841A enables reliable measurement of high-frequency power in electric vehicles and PCS (power conditioning subsystem for solar power).

Main applications

- Power measurement in the WLTP fuel efficiency performance evaluation test of vehicles
- Power measurement of batteries for electric vehicles
- Efficiency evaluation of PV inverter (power conditioner for solar power)

Anticipated Customers

- Automotive manufacturers, especially of ecological vehicle such as EVs and FCVs (fuel cell vehicles)
- Electric component manufacturers of devices such as transformers, motors, and reactors
- Renewable energy-related manufacturers of equipment such as wind and solar power generators
- R&D engineers dealing with power supply equipment

Shipping Start Date

February 22, 2022

New Current Sensors Specifications

ModelRated currentFrequency bandCable length
AC/DC Current probe CT6841A20 ADC to 2 MHz3 m
AC/DC Current probe CT6843A200 ADC to 700 kHz3 m
AC/DC Current probe CT6844A500 ADC to 500 kHz3 m
AC/DC Current probe CT6845A500 ADC to 200 kHz3 m
AC/DC Current probe CT6846A1000 ADC to 100 kHz3 m


Established in 1935, HIOKI E.E. CORPORATION (TSE: 6866) has grown to become a world leader in providing consistent delivery of test and measuring instruments through advanced design, manufacturing, and sales and services. By offering over 200 main products characterized by safety and quality while meeting an expansive range of applications, we aim to contribute to the efficiency and value of our customers' work in research and development, production and electrical maintenance. Hioki products and services are available around the world through our extensive network of subsidiaries and distributors. For more information, visit us at