Signal conditioning circuit of ACFM (Alternating Current Field Measurement) digital detector

Abstract

The invention provides a signal conditioning circuit of an ACFM (Alternating Current Field Measurement) digital detector, comprising a signal input circuit, a program control gain amplification circuit, a band-pass filtering circuit, a gain adjustable amplification circuit, a true effective value conversion circuit, a signal output circuit, an MCU (Micro-programmed Control Unit) interface and a self-adapting clock signal. The signal conditioning circuit is characterized in that: the signal input circuit is connected with the program control gain amplification circuit; the program control gain amplification circuit is connected with the band-pass filtering circuit; the band-pass filtering circuit is connected with the gain adjustable amplification circuit; the gain adjustable amplification circuit is connected with the true effective value conversion circuit; the true effective value conversion circuit is connected with the signal output circuit; the MCU interface is connected with the program control gain amplification circuit and the band-pass filtering circuit; and the self-adapting clock signal is connected with the band-pass filtering circuit. The signal conditioning circuit has the technical effects that: the defects that the applicability of the existing ACFM signal conditioning circuit is poor, the measurement type is single, the measurement precision is not high and the digital control cannot be realized are overcome; the signal conditioning circuit has the characteristics of wide applicable range, high detection precision, digital controllability and stable and reliable work, and can be applied to the signal conditioning circuit of the ACFM digital detector with the high cost performance.

Description

Technical field [0001] The invention relates to a signal conditioning circuit, in particular to a signal conditioning circuit of an ACFM digital detector. Background technique [0002] In recent years, based on eddy current testing and magnetic flux leakage testing, a new non-destructive testing technology has been developed-Alternating Current Field Measurement (ACFM). This technology uses conductive materials under the action of alternating current, and the defects and cracks of the material will change the distribution of the induced current around it, thereby changing the distribution of the induced magnetic field on the surface of the ferromagnetic test piece. By measuring the change of the induced magnetic field on the surface, and according to the inversion of the mathematical model, the length and depth of the crack defect are determined. [0003] During the use of ferromagnetic components, under the action of stress corrosion, fatigue load, internal working medium or exte...

AI Technical Summary

Problems solved by technology

[0009] The technical effect of the present invention is: it overcomes the disadvantages of the current ACFM signal conditioning circuit, such as poor applicability, single measurement type, low measurement accuracy and incapable of digital control, and has the characteristics of wide application range, high detection accuracy, digital controllability, stable and reliable operation , can be used in the signal conditioning circuit of cost-effective ACFM detection instrument

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