Portable alternating field measuring instrument based on magnetostriction principle

Abstract

The invention relates to a portable alternating magnetic field measuring instrument based on a magnetostrictive principle in the technical field of mensuration. The portable alternating magnetic field measuring instrument comprises: at least one magnetostrictive alloy bar is connected with a piezoelectric sheet by an elastomer; a conductive sheet is jointed with the underside of the piezoelectricsheet; the magnetostrictive alloy bar is exposed in air; a contact ring is fixed on the bottom of the a shell of the measuring instrument; exit sides of the conductive sheet are connected and communicated with conducting wires of the bottom of the shell of the measuring instrument respectively; the conducting wires are contacted with two contact rings respectively; a voltage signal wire is led out from the contact ring and is connected with a measuring display circuit; the measuring display circuit consists of a voltage amplifier and a controller; an input end of the voltage amplifier is connected with the contact ring; an output end of the voltage amplifier is connected with the controller; and the controller is connected with an A / D conversion module, a power management module, a liquidcrystal display module and a key-press module. The portable alternating magnetic field measuring instrument can reduce dimension to a millimeter level, and has good sensitivity, good temperature stability and large measuring range.

Description

Technical field [0001] The invention relates to an instrument in the technical field of measurement, in particular to a portable alternating magnetic field measuring instrument based on the principle of magnetostriction. Background technique [0002] There are basically two existing methods for measuring alternating magnetic fields. One is to use the induction method to measure the alternating magnetic field (coil type). An alternating current is passed through the Helmholtz coil, and the induced electromotive force generated by the detection coil in the Helmholtz coil is used to calculate the magnetic field strength at a certain point of the Helmholtz coil. When the angle between the normal direction of the detection coil and the axis of the Helmholtz coil is different, the amplitude of the induced electromotive force ε m Also different, its size is proportional to cosθ. Its measuring range can reach 7.96~7.96×10 4 A / m. The other is to use Hall elements to measure alternating...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a portable alternating magnetic field measuring instrument based on the principle of magnetostriction in view of the deficiencies of the prior art, which can reduce the size to millimeter level, has good sensitivity and good Excellent temperature stability and large measurement range, overcome the problems of existing coil type size and insufficient signal sensitivity, and at the same time solve the defects of poor temperature stability and small measurement range of Hall type, and solve the problem that the general alternating magnetic field measuring instrument must The problem with being powered by a cable or not being portable

Images