A Model of the Calibration Blocks of the Magnetic Susceptibility of Disperse Materials for Devices Intended for Magnetic Susceptibility Measurements: III. Metrological Assessment of Calibration Blocks

Abstract

Methods for the metrological assessment of the magnetic susceptibility of calibration blocks χ CB made on the basis of a homogeneous disperse weakly magnetic mixture of ferromagnetic and paramagnetic materials are presented. For a confidence level of 0.95, the overall relative error in measurements of χ CB is 6.5% for the first specimen, 4% for the second specimen, and 3.5% for the third specimen. These results allow efficient use of the developed set of calibration blocks for calibrating devices for measuring magnetic susceptibility. INTRODUCTIONIn study [1], a set of three calibration blocks (CBs) is experimentally assessed. Mean arithmetic values of the magnetic susceptibility are found for the specimens, which equal = 535 × 10 -5 SI units for the first specimen, -= 1090 × 10 -5 SI units for the second, and = 2450 × 10 -5 SI units for the third. However, the developed set of the CBs can only be used for calibrating magnetic susceptibility measurement devices after its metrological characteristics have been assessed. The assessment has to determine the normalized error of each CB, which may not exceed 1/3 of the devices' error [2]. Therefore, during determination of the magnetic susceptibility of CBs made from a disperse weakly magnetic mixture, it is necessary to investigate in detail the sources of error involved.The aim of this part of the study is to provide a metrological assessment of the errors during determination of the magnetic susceptibility of CBs in a broad range of the susceptibility's variation.