Design of measuring amplifiers for magnetic measurement

The purpose of this paper is a design of a measuring preamplifier for a fluxmeter which was designed in Department of Theoretical and Experimental Electrical Engineering which is used for hysteresis loops on ferromagnetic materials measurements. Having respect to measure coils characteristics and processed voltage levels with ranges in nV and μV, there was necessary to in-vestigate measure principles of such low voltage. And then choose an appropriate operational am-plifier. Mainly with minimum input residual voltage and offset temperature dependency. Also was necessary to propose effective zero compensation and eliminate thermoelectric influence in the whole designed device. There was applied noise optimization of selected operational amplifier in PSpice software. And in the last part of the paper will be show results of noise measurement on the amplifier. The given results will be evaluated together with possibilities of application for a meas-urement purposes in labs.