# Current measurement including multiple frequency components (Current sensor)

## QI'd like to use a Hioki current sensor to measure a current that contains multiple frequency components. What is the measurable current value? (AC/DC Current Probe, AC/DC Current Sensor, AC/DC Current Box)

A

Follow the calculation example below.
Hioki products include two types of current sensors that use the zero-flux gate method: wide-band current probes and high-accuracy current sensors.
These two types of current sensors use different technologies for magnetic cores and windings, and have slightly different concepts for the measurable range based on frequency derating.

In the case of a high-accuracy current sensor which uses a fluxgate:
Referring to the product specifications, the sum of the squares of the ratios of the frequency derating value and the measured value for each frequency shall not exceed 1.

(A: Frequency measured value / A: Derating value at frequency)^2 + (B: Frequency measured value / B: Derating value at frequency)^2 + (C ...) ≤ 1

(Calculation example)
In the case of Model CT6904A
Derating value for each frequency: 550 A(DC) + 25 A (1 MHz)
Measured value: 500 A (DC) + 10 A (1 MHz)
(500/550)^2+(10/25)^2 ≒ 0.99 (Alright because it is less than 1.0)

- Applicable models
Only the current available products on 22nd Feb., 2022 are listed:
AC/DC Current Probe CT6841A, CT6843A, CT6844A, CT6845A, CT6846A
AC/DC Current Sensor CT6862-05, CT6863-05, CT6872, CT6872-01, CT6873, CT6873-01
AC/DC Current Sensor CT6875A, CT6875A-1, CT6876A, CT6876A-1, CT6877A, CT6877A-1
AC/DC Current Sensor CT6904A, CT6904A-1, CT6904A-2, CT6904A-3
AC/DC Current Box PW9100A-3, PW9100A-4