FAQ | Feb 16,2023
The main equipment used to detect the current sensor is: standard current sensor, sensitivity S=0.01V/A, the maximum allowable error +1%; Digital oscilloscope, analog bandwidth 2.5GHz, maximum allowable error of vertical deflection factor ±1%; Surge generator, maximum output voltage 30kV, maximum allowable error ±5%, maximum output short-circuit current 20kA, leading edge and pulse width (8/20us), maximum allowable error ±5%. The detection process is: the standard current sensor and the calibrated current sensor are simultaneously connected to the short-circuit current output wire of the surge generator, and the induced voltage output end of the current sensor is connected to the oscilloscope. In general, the standard current sensor is connected to channel 1(CH1) of the oscilloscope, and the calibrated current sensor is connected to channel 2(CH2) of the oscilloscope.
After the connection is completed, the output voltage on the surge generator panel is set to give the excitation signal. At this time, the waveform of the standard current sensor and the calibrated current sensor is displayed on the oscilloscope, and the waveform parameters are selected as pulse voltage amplitude and pulse width. Because the standard current sensor used and the calibrated current sensor are the same level, so the direct comparison method is used in the detection. The standard current sensor is traceable and has a measurement error of 0.5%, so it can be directly used to detect other types of current sensors with a measurement error range of ±1.5%. During detection, the wire through which the current is calibrated passes through the center of the coil, and the voltage value at both ends of the wire is obtained according to the principle of electromagnetic induction. This voltage value is also the voltage value through the standard current sensor, according to the sensitivity of the standard current sensor can be calculated. Because it comes from the same wire, the current value of the calibrated current sensor is equal to the current value of the standard current sensor, that is, is labeled. The voltage value of the calibrated current sensor is obtained by detailed counting of oscilloscope, and the sensitivity of the calibrated current sensor is calculated by proportional relation.
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