Схеми ввімкнення та основні розрахункові співвідношення індукційних магнітометрів

Abstract

Подано схеми ввімкнення та основні розрахункові співвідношення індукційних магнітометрів та розглянуто принцип дії та основні схеми ввімкнення індукційного магнітометра. Наведено передавальну функцію індукційного магнітометра, амплітудно-частотну характеристику вихідної напруги U0 в резонансному режимі. Описано три способи отримання такої характеристики.In article “Schemes of enabling and the basic calculated ratio of induction magnetometers (IM)” is considered the basic principle of IM operation and the basic scheme of it’s enabling. Analyzed frequency response of IM. The definition of IM sensitivity threshold is given in this article. Described the transfer function of IM. Analyzed the amplitudefrequency characteristic (AFC) of output voltage U0 in resonant mode. Described three ways of obtaining such AFC. Displayed the scheme and AFC with the current amplifier and equivalent circuit and AFC of IM with negative feedback on the magnetic field. Analyzed the AFC of IM. Presented noise signal scheme of IM with a feedback in the magnetic field and expressions of output voltage US, conversion factor of Gн(ω) and the phase shift of the voltage US relative to the measured magnetic field. Derived an equation for the frequency inflection, from which the expressions for the lower and upper frequency inflection was obtained. Presented the determine of sensitive threshold of IM and the physical meaning of sensitive threshold of IM. It is shown how the threshold is determined. Displayed the expression of resulting density of IM noise by it’s power WB and the expression of resulting density of IM noise in terms of measured magnetic field. To measure magnetic fields in applied geophysics, board space experiments, biomedical research, non-destructive testing and technical diagnostics in problems of electromagnetic compatibility and control side electromagnetic radiation devices and systems commonly used induction magnetometers (MI), which have very wide frequency range of effective application (from ~10-4 to ~106 Hz) and can measure magnetic fields in a large dynamic range (from fractions to tens of T) [1–6]. Their high sensitivity and ability to work in a wide frequency range combined with simplicity and high reliability and manufacturability explains the increased interest in these devices. The purpose of this work – to improve methods of calculating the transfer function of MI and their sensitivity threshold to improve IM settings used in geophysics.