CT6904A Series AC/DC Current Sensor

Detailed Product Overview

The HIOKI CT6904A AC/DC pass-through current sensor is engineered for high-precision current measurements, supporting currents up to 500 A with a wide frequency bandwidth from DC to 4 MHz. Employing advanced zero-flux detection with flux gate technology, the sensor achieves exceptional linearity of ±5 ppm and a high common-mode rejection ratio of 120 dB at 100 kHz. In addition, the sensor features an exceptionally flat frequency response, ensuring stable performance across a wide bandwidth even in demanding test environments.

Easy connection to analyzers and DAQs 

The CT6904A works directly with HIOKI Power Analyzers and Memory Recorders, which supply power to the sensor via the ME15W connector. When combined with a HIOKI sensor unit (CT9555, CT9556, or CT9557), it can also be used with oscilloscopes or other DAQ systems, providing a voltage output ratio of 4 mV/A. Its robust construction, 32 mm (1.26 in) core diameter, 3-meter cable length, and maximum voltage rating of 1000 V CAT III ensure flexible installation and safe high-voltage operation across diverse applications. 

Unmatched accuracy across the full frequency range 

Outstanding measurement accuracy makes the CT6904A an ideal choice for applications where precision is critical. It achieves a basic accuracy of ±0.025% of reading plus ±0.007% of full scale for DC measurements. For AC measurements, the basic accuracy is ±0.02% of reading plus ±0.007% of full scale. Combined with its wide frequency bandwidth, this performance ensures reliable results across both low- and high-frequency applications. 

Another key advantage of the CT6904A is its exceptionally flat frequency response. Across a wide bandwidth, the group delay remains nearly constant, which is essential for accurate phase correction. Thanks to this stability, a single-point correction can effectively minimize phase error across the entire frequency range. This enables automatic phase correction with the HIOKI PW8001 Power Analyzer. It also allows straightforward deskew-type correction when using third-party analyzers or DAQ systems, ensuring consistent accuracy in a wide range of test environments.

Consistent results even at high frequencies

Compared to other current sensors on the market, the CT6904A minimizes the impact of conductor position on measurement values, ensuring highly reproducible results. While the effect of conductor position typically becomes more significant at higher frequencies, the CT6904A effectively reduces this impact, delivering stable and reliable measurements. This high reproducibility is especially valuable when comparing the losses of multiple inductors or transformers, establishing the CT6904A as a top choice for loss measurements in such applications. 

Thanks to its stable frequency characteristics, the CT6904A enables highly accurate phase correction across a wide bandwidth. This allows precise power analysis not only with HIOKI Power Analyzers such as the PW8001, but also with third-party analyzers and DAQ systems. These capabilities make the sensor ideally suited for evaluating high-frequency inductor and transformer losses, wireless charging systems, and EV inverter motors.