Low-noise four-wire system measuring device and method

Abstract

The invention provides a low-noise four-wire system measuring device which comprises a measuring bus, the measuring bus comprises two voltage measuring wires and two current excitation wires, and the voltage measuring wires and the current excitation wires are distributed on the two sides of a resistor R to be measured. The low-noise four-wire system measuring clamp has the advantages that when the low-noise four-wire system measuring clamp is used for measuring, the two measuring connecting lines are placed on the two sides of the measured resistor, so that the current loop and the voltage loop do not have other intersections except the measured resistor; due to the fact that the current loop, the voltage loop and the measured resistor are the common intersection of the current loop, the voltage loop and the measured resistor, but according to the electromagnetic induction principle, due to the fact that the intersection area of the two loops is very small, the influence of noise on measurement data is greatly reduced. And the generated induced electromotive force is very small, so that the generated noise influence is very small.

Description

【Technical field】 [0001] The invention relates to the field of electronic technology, in particular to a low-noise four-wire measuring device and method. 【Background technique】 [0002] The application of Kelvin four-wire detection method in weak signal measurement. Since the amplitude of the weak (voltage, current, resistance) signal itself is too small, and the amplitude of the noise signal may be several times that of the weak signal, this causes the useful weak signal itself to be submerged by the noise signal, and the weak signal is in the necessary amplification process. Noise signals are also amplified, making accurate measurements of weak signals difficult. Many physical quantities must be converted into electrical signals before they can be measured. The signals of these physical quantities are very weak themselves, and they are even weaker after they are converted into electrical signals. Therefore, accurate measurement of weak signals is a common problem that is ...

AI Technical Summary

Problems solved by technology

Are 4-wire measurements not available at the nano-ohm level? Faced with this problem, many measuring instruments that use AC signal sources in practical applications solve it by adding band-pass filters to the circuit. Although the noise signal can be reduced at a great cost, it cannot be completely eliminated; using a DC signal source The measuring instrument reduces the noise by adding and dividing the two times of current forward and reverse measurements, but it cannot be completely eliminated; after a lot of repeated experiments, a solution to greatly reduce the noise signal is found

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