High-precision Current Testing

Hioki's clamp type AC/DC current sensors can be connected directly to Hioki Power Analyzers and Memory HiCorders.
Also, it can be connected to Power Meters, Oscilloscopes, DMMs, etc. by using an optional sensor unit.

Use with an instrument with a high input impedance of 1 MΩ or higher.

Key Features

  • Frequency bandwidth DC to 2 MHz
  • Rated current 20 A AC/DC
  • Power supplied via the measurement instrument (when connecting Hioki Power Analyzer or Memory HiCorder)
  • Ideal for use in environmental testing with broad -40°C to 85°C temperature range
  • Ideal for EV inverter evaluation and PV power generation PCS evaluation
  • Single-handed operation and robust locking mechanism

Model No. (Order Code)

Note: These products cannot be used alone.

Clamp-type sensors that eliminates the need to cut lines

Clamp-style current sensors can be affixed without cutting the line under measurement. Thanks to that design, they can measure current in applications where it’s not possible to cut lines, including testing of EVs on chassis dynamometers and evaluation of operational solar power systems.

CT684xA feature image


Fuel efficiency testing that complies with the WLTP international standard

The CT6840A series can measure current in operating vehicles since there’s no need to cut cables. Combined with a power analyzer, these instruments can accurately integrate current and power during charging and discharging of system batteries in order to make WLTP-compliant fuel efficiency measurements.

Realizing unparalleled measurement precision in a clamp-style design

While clamp-style current sensors are generally praised for their convenience, they usually pose disadvantages in terms of measurement precision. However, the CT6840A series delivers unparalleled measurement precision in a clamp-style design, allowing accurate measurement of DC power in battery-powered EVs and solar power systems.

Five-model line with a maximum current rating of 1000 A

Rated current/Frequency band/Diameter of measurable conductors
CT6841A: 20 A/DC to 2 MHz/φ20 mm or less
CT6843A: 200 A/DC to 700 kHz/φ20 mm or less
CT6844A: 500 A/DC to 500 kHz/φ20 mm or less
CT6845A: 500 A/DC to 200 kHz/φ50 mm or less
CT6846A: 1000 A/DC to 100 kHz/φ50 mm or less

Accurate current measurement across a broad operating temperature range of -40°C to 85°C

Temperature characteristics are an issue for current sensors that can manage DC current. The CT6840A series uses the flux gate detection method. Unlike the standard Hall element detection method, the flux gate method is more resistant to temperature variations, allowing instruments to accurately measure current in a variety of test environments.

Compatible with the Power Analyzer PW8001’s automatic phase correction function

The CT6840A series provides automatic phase correction for automatically correcting current sensor phase just by connecting to the Power Analyzer PW8001. This function automates configuration of phase correction values, a process that previously had to be carried out manually, eliminating settings errors and facilitating accurate power measurement. (All current sensors have phase characteristics, and the Power Analyzer performs phase correction so that power can be measured accurately.)

Basic specifications

Accuracy guaranteed: 1 year
Rated current 20 A AC/DC
Frequency bandwidth DC to 2 MHz
Diameter of measurable conductors Max. φ 20 mm (0.79 in.)
Max. allowable input ±60 A peak
(Within 20 ms in an environment of 40°C/104°F or less)
Output voltage 100 mV/A
Output resistance 50 Ω ± 10 Ω
Accuracy (amplitude)
±(% of reading + % of full scale)
DC: 0.2% + 0.05%
DC < f ≤ 100 Hz: 0.2% + 0.01%
Linearity ±20 ppm Typical
Common-Mode Voltage Rejection Ratio
DC to 1 kHz:140 dB or greater
1 kHz to 10 kHz:125 dB or greater
10 kHz to 100 kHz:100 dB or greater
100 kHz to 1 MHz:80 dB or greater
(effect on output voltage and common mode voltage)
Automatic phase correction Automatically performs phase correction when connected to PW8001
Operating temperature, humidity -40°C to 85°C (-40°F to 185°F), 80% RH or less
Withstand voltage AC 4260 V
Power supply Power suppled via the Power Analyzer PW8001, PW6001, PW3390, Sensor Unit CT9555, CT9556, CT9557, or 3CH CURRENT UNIT U8977
Max. rated power 5 VA or less (When measuring 20 A/55 Hz with ±12 V power supply)
Dimensions and mass Approx. 153 mm W × 67 mm H × 25 mm D
(approx. 6.02 in. W × 2.64 in. H × 0.98 in. D), 370 g (13.1 oz.)
Cable length Approx. 3 m (9.84 ft.)
Included accessories Markup bands ×6, Carrying Case, Instruction Manual

External power supply, connection cord (5)

Conversion cable/extension cable (2)

The CT9902 connects up to 2 cables in series (Accuracy addition required)

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