Consistent, High-precision Current Testing Across a Wide Temperature Range



Hioki AC/DC clamp sensors are best-in-class current sensors for use with power meters, Memory HiCorders and high performance oscilloscopes. The CT6841 is DC to 1 MHz/20 A sensors, ideal for capturing signals during the efficiency testing of batteries, inverters and power conditioners.

Key Features
• Ideal for use in environmental testing with broad -40˚C to 85˚C temperature range
• High precision with a clamp-type design, ±0.3% amplitude accuracy, ±0.1° phase accuracy
• Wide-bandwidth DC to 1 MHz
• Single-handed operation and robust locking mechanism
• Reduced effects from magnetic fields, conductor position, and noise from nearby wires
• For EV/HEV battery charge and discharge efficiency measurement and inverter and power conditioner conversion efficiency evaluation

Model No. (Order Code)

CT684120 A AC/DC
CT6841-0520 A AC/DC, ME15W terminal

Note: These products cannot be used alone. The optional SENSOR UNIT is required in order to supply power and connect the clamp to a Memory HiCorder or other instrument. Products can be directly connected to the compatible Power Meters and Power Analyzers.

Good Design
3 year


Germany iF Design Award

High-accuracy current sensors ideal for use with oscilloscopes and power meters

Compared to current sensors that use Hall elements, flux gate type current sensors are not prone to measurement error caused by variations in the external temperature. In addition, they can measure extremely low input (current values) and current waveforms with phase that lags by 90° with a high degree of precision. The CT6840 Series AC/DC Current Probes are ideal for measuring power waveforms with a digital oscilloscope and power meters.

Ideal for thermostatic chambers and engine rooms

The CT6841 series is ideal for operational evaluations of devices inside equipment that is subject to extreme temperature changes, offering tough, high-precision testing thanks to its broad temperature characteristics and an operating temperature range of -40°C to 85°C. The clamp sensor's tough performance helps ensure you can make the measurements you need.

Measure the charge and discharge efficiency of EV/ HEV batteries

In many situations, it is not possible to use high-accuracy pass-through sensors to evaluate EVs and HEVs since their wiring cannot be easily disconnected. The CT6841’s clamp-type design and resin casing make them more resistant to deformation from heat than that used in legacy products, allowing you to take measurements under the hood with extremely high precision.

Basic specifications (Accuracy guaranteed for 1 year, Post-adjustment accuracy guaranteed for 1 year)

Rated current20 A AC/DC
Max. allowable input40 A rms (requires derating)
Frequency characteristicsAmplitude: DC to 1 MHz
Phase: DC to 300 kHz
Amplitude and Phase accuracyDC ±0.3 % rdg. ±0.05 % f.s. (Phase: Not defined)
DC < f ≤ 100 Hz ±0.3 % rdg. ±0.01 % f.s. (Phase: ±0.1°) Defined to 1 MHz
Power consumption5 VA max. (at 20 A/55 Hz, ±12 V power requirement)
Output voltage0.1 V/A (CT6841), 0.01 V/A (CT6843)
(voltage output with the Sensor Unit, use with a device having a 1 MΩ input resistance or higher)
Core diameterφ 20 mm (0.79 in)
Operating temperature, humidity-40 °C to +85 °C (-40 °F to 185 °F), 80% rh or less (with no condensation)
Power supply±11 V to ±15 V DC (Power suppled via the Sensor Unit, which supports 100 to 240 V AC)
Dimensions and mass153 mm (6.02 in)W × 67 mm (2.64 in)H × 25 mm (0.98 in)D, 350 g (12.3 oz), cord length: 3 m (9.84 ft)
AccessoriesInstruction manual ×1, Mark bands ×6, Carrying Case ×1

Compatible models...CT6841 (-05)

Compatible modelsCT6841CT6841-05
Power Analyzer PW6001, PW3390△ (Requires CT9900)OK
Power Analyzer 3390OK△ (Requires CT9901)
Power HiTester 3193 seriesOK△ (Requires CT9901)
Current Unit 8971△ (Requires the 9318)△ s (Requires the 9318, CT9901)
F/V Unit 8940△ (Requires the 9318, 9705)△ (Requires the 9318, 9705, CT9901)



SENSOR UNIT CT9555, CT9556, CT9557


Technical Notes


High-precision, Wideband, High Stable Current Sensing Technology

Declaration of Conformity

AC/DC CURRENT PROBE CT6841,CT6841-05,CT6843,CT6843-05,CT6844,CT6844-05 [100KB]

User Guides

Electrical Measurements of Lithium-Ion Batteries

Current Measurement Method for Electric Wire with Shield