# Hioki CT6904 AC/DC Current Sensor, 500 A, 4 MHz # Hioki CT6904 AC/DC Current Sensor, 500 A, 4 MHz ## Key Features At A Glance - Rated primary current: 500 A AC/DC for measurement of large currents - 4 MHz (±3 dB typical) measurement frequency range - Basic measurement accuracy: ±0.02% rdg. ±0.007% f.s. (45 Hz to 65 Hz) - Linearity: ±10 ppm typical at 23°C - Common-Mode Rejection Ratio: 140 dB or greater at 50/60 Hz; 120 dB or greater at 100 kHz - Maximum rated voltage to ground: 1000 V CAT III - Diameter of measurable conductors: φ32 mm or less - Output voltage: 4 mV/A, connects via ME15W 12-pin terminal interface The Hioki CT6904 is an ultra-high performance AC/DC current sensor rated for 500 A AC/DC primary current with a 4 MHz (±3 dB typical) measurement frequency range. The sensor uses a Zero Flux (Fluxgate Detection) measurement method, combining a fluxgate element for DC to low frequency current detection with newly developed opposed split coil winding technology for high frequency current detection. This architecture delivers a wide measurement range from DC to 4 MHz from a single sensor body that accepts conductors up to φ32 mm in diameter. The CT6904 is designed for current measurement applications where both wide bandwidth and high accuracy are required at the same time. Applications described on the datasheet include high-precision efficiency testing of SiC and GaN inverters, where the sensor measures both the fundamental wave current and the switching frequency current and its harmonics during PWM output, and reactor and transformer loss analysis in power converter development, where switching current that has been obscured by noise on conventional sensors can be measured accurately. The sensor is built to support the demands of the power electronics, natural energy, and automotive industries. ## Accessories Supplied - Instruction manual - Carrying case - Color labels (for channel identification) ## Product Core & Specifications Category Specification Value Basic Specifications Rated primary current 500 A AC/DC Diameter of measurable conductors φ 32 mm (1.26 in) or less Maximum input current Within derating shown in figure. Up to ±1000 A peak allowable if within 20 ms (design value). When measuring current in the vicinity of derating, use a cooling time that is 10x or more greater than current input time. Output voltage 4 mV/A Maximum rated voltage to ground 1000 V CAT III; Expected transient overvoltage: 8000 V Linearity ±10 ppm Typical (23°C / 73°F) Offset voltage ±10 ppm Typical (23°C / 73°F, no input) Accuracy Guarantee Conditions Guaranteed accuracy period 1 year Guaranteed accuracy period after adjustment by Hioki 1 year Temperature and humidity for guaranteed accuracy 23°C ±5°C (73°F ±9°F), 80% RH or less Warm-up time 30 min. or more Input waveform / Connection Sine wave; measuring instrument with input resistance of 0.9 MΩ to 1.1 MΩ; terminal-to-ground voltage 0 V; no external magnetic field; conductor center position Accuracy (Amplitude / Phase) DC ±0.025% rdg. ±0.007% f.s. DC < f < 16 Hz ±0.2% rdg. ±0.02% f.s. / ±0.1° 16 Hz ≤ f < 45 Hz ±0.1% rdg. ±0.02% f.s. / ±0.1° 45 Hz ≤ f ≤ 65 Hz ±0.02% rdg. ±0.007% f.s. / ±0.08° 65 Hz < f ≤ 850 Hz ±0.05% rdg. ±0.007% f.s. / ±0.12° 850 Hz < f ≤ 1 kHz ±0.1% rdg. ±0.01% f.s. / ±0.4° 1 kHz < f ≤ 5 kHz ±0.4% rdg. ±0.02% f.s. / ±0.4° 5 kHz < f ≤ 10 kHz ±0.4% rdg. ±0.02% f.s. / ±(0.08×f)° 10 kHz < f ≤ 50 kHz ±1% rdg. ±0.02% f.s. / ±(0.08×f)° 50 kHz < f ≤ 100 kHz ±1% rdg. ±0.05% f.s. / ±(0.08×f)° 100 kHz < f ≤ 300 kHz ±2% rdg. ±0.05% f.s. / ±(0.08×f)° 300 kHz < f ≤ 1 MHz ±5% rdg. ±0.05% f.s. / ±(0.08×f)° Frequency range 4 MHz (±3 dB Typical) Effects of Temperature Range \-10°C to 18°C (14°F to 64°F) or 28°C to 50°C (82°F to 122°F) Amplitude sensitivity ±0.005% rdg./°C Offset voltage ±0.005% f.s./°C Phase ±0.01°/°C Noise Rejection Common-mode voltage rejection ratio (CMRR) 140 dB or greater (50 Hz/60 Hz); 120 dB or greater (100 kHz) Effect of conductor position ±0.01% rdg. or less (100 A input, 50 Hz/60 Hz), using wire with 10 mm (0.39 in) outer diameter General Specifications Operating environment Indoors, Pollution Degree 2, altitude up to 2000 m (6562.20 ft) Operating temperature and humidity \-10°C to 50°C (14°F to 122°F), 80% RH or less (no condensation) Storage temperature and humidity \-20°C to 60°C (-4°F to 140°F), 80% RH or less (no condensation) Dielectric withstand voltage 7.4 kV AC (sensed current of 1 mA), 50 Hz/60 Hz: 1 min (distance between feed-through window and cable output terminal) Power supply Supplied from PW6001, PW3390, and CT9555 Max. power consumption 7 VA (500 A/55 Hz measurement, with a power supply of ±12 V) Interface Dedicated interface (ME15W) Dimensions Approx. 139 mm (5.47 in) W × 120 mm (4.72 in) H × 52 mm (2.05 in) D (excluding protrusions and cables) Output cable length Approx. 3 m (9.84 ft) including relay box (10 m / 32.81 ft made-to-order option available) Bracket hole diameter φ 5.2 mm (0.20 in) (M5 screws, recommended tightening torque: 1.5 N·m to 2.0 N·m) Physical Mass Approx. 1.0 kg (35.3 oz); 10 m output cable variant approx. 1.3 kg (45.9 oz) Product warranty period 3 years Connectable Products Power Analyzer PW6001 Combined accuracy per datasheet table Power Analyzer PW3390 Add PW3390 accuracy and CT6904 accuracy (consider sensor rating when calculating f.s. error) Sensor Unit CT9555 Combined accuracy: sensor accuracy × 1.5 (when output coaxial cable is no longer than 1.6 m / 5.25 ft) **Important:** Maximum input current must remain within the derating curve shown on the datasheet. Up to ±1000 A peak is allowable if within 20 ms (design value). When measuring current in the vicinity of derating, use a cooling time that is 10× or more greater than the current input time.**Important:** Power for the CT6904 is supplied through the dedicated ME15W interface from a connectable host instrument (Hioki POWER ANALYZER PW6001, POWER ANALYZER PW3390, or SENSOR UNIT CT9555). The sensor cannot be operated standalone; a compatible host must be ordered or already owned.**Important:** When measuring current in the vicinity of the derating curve, use a cooling time that is 10x or more greater than the current input time. Up to ±1000 A peak input is allowable only if within 20 ms (design value).**Important:** Specifications for the 10 m (32.81 ft) output cable length variant differ from the standard 3 m configuration: add amplitude accuracy of ±(0.015×f)% rdg. for 50 kHz < f ≤ 1 MHz, and the frequency range is reduced to 2 MHz (±3 dB Typical). With the PW3390 host and a 10 m cable, the frequency range is 1 MHz (±3 dB Typical).**Important:** The Fastening Bracket and the 10 m output cable configuration are made-to-order options and are not stocked items — lead time and availability should be confirmed at order.Recommended pairing: connect the CT6904 to the Hioki PW6001 Power Analyzer via the ME15W interface for the combined current and power accuracy values published in the datasheet, including the phase compensation function used in reactor and transformer loss measurements. **Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.** ## Details - **Price:** 5250.0 USD - **Vendor:** Hioki - **Type:** Curr Probe - **Tags:** Current, Hioki, Manufacturers, Other Equipment, Probe, product_manual_group_3, Product_new ## Variants | Variant | Price | Available | |---------|-------|-----------| | Default Title | 5250.00 USD | In stock | ## Images - Hioki CT6904 AC/DC Current Sensor, 500 A, 4 MHz --- > Source: [ValueTronics](https://valuetronics.com/products/ct6904-hioki-current-probe-new) > Updated: 2026-05-30