A four-terminal method high-value capacitive impedance measuring device and its measuring method

Abstract

The invention relates to a four-terminal high-value capacitance measuring device and its measuring method. The measuring device includes an induction shunt, a capacitor box, a standard resistor, a resistance box, a capacitor to be tested, a digital voltmeter, and a power supply; the induction shunt includes a turn A pair of windings with a ratio of 1:1; the capacitor box and the standard resistor are connected in series to form the measurement circuit A; the resistance box and the capacitor to be tested are connected in series to form the measurement circuit B; a pair of windings of the induction shunt is reversely connected to the two measurement circuits Middle; the standard resistor and the capacitor to be tested are respectively connected by the four-terminal method; this measurement method makes the current values ​​in the two measurement loops equal by adjusting the impedance balance, and then obtains the measured value through the discrete Fourier transform method and synchronous sampling technology. The series equivalent capacitance value and loss factor of the capacitor; the invention realizes isolation and floating measurement, which can not only eliminate the interference of the power supply to the measurement device, but also avoid the influence of the current on the calibration result, and greatly improve the accuracy of capacitance measurement .

Description

technical field [0001] The invention relates to a measuring device in the field of electromagnetic measurement, in particular to a four-terminal method high-value capacitive impedance measuring device and a measuring method thereof. Background technique [0002] In recent years, domestic and foreign manufacturers have produced various physical and equivalent high-value standard capacitors, with an accuracy of 0.05% to 2%, and a capacity of mF level. These standard capacitors are in urgent need of verification or calibration; commonly used impedance measuring instruments, Such as GR7600, Agilent4284A, etc., also need to be verified or calibrated in the range of high value capacity. However, my country has not established a traceability system for high-value capacitors. When measuring high-value capacitors, some manufacturers and metrology departments often use uncalibrated impedance measuring instruments for measurement, which cannot guarantee the reliability and accuracy of ...

AI Technical Summary

Problems solved by technology

[0009] In order to solve the problem of relatively large measurement errors in the prior art, the present invention provides a four-terminal high-value capacitive impedance measuring device and measurement method, which utilizes a new four-terminal high-value capacitive measurement that combines inductive shunt technology and sampling technology. The method realizes the capacity measurement of capacitors with a capacity range of 10μF to 1mF and a frequency range of 100Hz to 1kHz

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