Digital multimeter non-linear error compensation method

Abstract

The invention discloses a digital multimeter non-linear error compensation method which comprises the following steps: a range of reference values input by an amplifier input end is divided into five sections, the number of segments of the sections is set according to a ratio between non-linear absolute error in the sections and non-linear absolute error allowed in the sections, and each section is evenly segmented according to the number of segments; for each segment, a number of groups of data is obtained; each group of data comprises a reference value and a corresponding measured value, reference values of two groups of data are positioned at end points of a segment, a measured value range corresponding to the segment is obtained according to corresponding measured values, each segment is subjected to polynomial fitting operation according to fitting data, a polynomial formula is therefore obtained, a corresponding polynomial formula is chosen according to the measured value range corresponding to the measured values during actual measurement processes, and a corrected value is obtained via calculation. Via the digital multimeter non-linear error compensation method, non-linear error caused by an amplifier and an ADC in a digital multimeter can be compensated, and linear performance of the digital multimeter can be improved.

Description

technical field [0001] The invention belongs to the technical field of digital multimeters, and more specifically relates to a nonlinear error compensation method for digital multimeters. Background technique [0002] During the manufacturing process of the digital multimeter, due to the errors of various components, it is difficult to guarantee the accuracy of the measurement results. Among the major measurement functions of the digital multimeter, amplifiers and digital-to-analog conversion circuits need to be applied in the measurement circuit. Each measurement signal is amplified by the amplifier and sent to the digital-to-analog conversion circuit for acquisition, quantification and subsequent processing. Amplifier errors are mainly offset errors, gain errors, nonlinear errors, offset and gain drift errors caused by temperature. The digital-to-analog conversion circuit errors mainly include ADC (Analog-to-Digital Converter, analog-to-digital converter) integral nonline...

AI Technical Summary

Problems solved by technology

At present, the main means to solve the nonlinear error of the digital multimeter in the industry is to choose a device with better linear performance, but this also increases the cost of the digital multimeter accordingly, and the linear performance of the device will gradually decrease with use, and the non-linear The error is gradually increasing, and it is difficult to guarantee the accuracy of the digital multimeter measurement results for a long time

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