Untitled

A Model of the Calibration Blocks of the Magnetic Susceptibility of Disperse Materials for Devices Intended for Magnetic Susceptibility Measurements: II. Experimental Estimates for the Parameters of Calibration Blocks

“…The magnetic susceptibility of a disperse ferromagnetic mixture used in CBs was determined according to the following formula: (1) where I CB is the amperage, in A, in the compensating coil determined using the condition of equality between the magnetic induction values of the leakage magnetic fields created by the compensating coil and the investigated CB.…”

“…As was shown in the first part of this study [1], calculation methods are only applicable for normalizing the limiting values of a disperse mixture's magnetic susceptibility and, in particular, the values close to 2 SI units, which are due to encasement of the mixture in a spherical shell made of a dielectric with a magnetic susceptibility of the material of ~ 10 -5 SI units. These calculations were used as a basis for making a calibration specimen that consists of a disperse ferromagnetic mixture made of grade 600 HH ferrite ( χ m > 400 SI units) encased in a spherical glass bulb and compressed to a volume concentration of C V ≅ 0.9, i.e., to 90%.…”

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

“…As follows from [4,5], during assessment of a random absolute error, its confidence levels can be determined according to the formula (1) where t P is Student's coefficient depending on adopted confidence level P and number n of the measurements of physical quantities, and x i and are the results of the i th measurement and the measurement of a physical quantity (i.e., the arithmetic mean for the corrected measurement results), respectively.…”

“…The vessel was placed at the center of the magnetizing solenoid of a measurement device. The vessel's neck was oriented in the direction away from the sensor of a fluxgate magnetometer (see Fig. in [1]). The amperage supplied to the compensating coil then was measured five times when the fluxgate magnetometer's readings were close to zero.…”

“…In 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.…”