User:Stan Zurek/Measurement system A

Operating principle
This measurement system follows the principles described in the international standard: IEC 60404-6, Magnetic materials - Part 6: Methods of measurement of the magnetic properties of magnetically soft metallic and powder materials at frequencies in the range 20 Hz to 200 kHz by the use of ring specimens

Description

 * PC - desktop PC with Windows XP operating system
 * LabVIEW - National Instruments LabVIEW 2012, {accessed 23 Nov 2012}
 * Data acquisition card - National Instruments DAQ PCI-6120, {accessed 23 Nov 2012}
 * Power amplifier - Analogue Associates / Crown Macro-Tech 3600VZ Power Amplifier (MA3600VZ), {accessed 23 Nov 2012}
 * Isolating transformer - 1 kVA, 50-50-250-250 (to block DC offset of the power amplifier)
 * Shunt resistor - non-inductive high-power shunt resistor, 1Ω for higher flux density range, 50Ω for lower range
 * Toroidal sample - sample under test provided already in toroidal shape
 * Single strip tester - a tester capable of measuring single samples with Epstein frame dimensions
 * B-coil - a search coil wound around the sample under test to detect the dB/dt signal

Digital feedback
The system uses digital feedback algorithm developed at Wolfson Centre for Magnetics, Cardiff University, UK, which was described in this paper:


 * Zurek S., Marketos P., Meydan T., Moses A. J., Use of novel adaptive digital feedback for magnetic measurements under controlled magnetizing conditions, IEEE Transactions on Magnetics, Vol. 41, No. 11, November 2005, p. 4242-4249,

The system is capable of controlling the shape of waveform of flux density or magnetic field strength to within +/- 1% as specified in the above-mentioned IEC standard.

Calibration
The results of this system were compared to a system used at Wolfson Centre for Magnetics. For grain-oriented electrical steel grade M4, for toroidal samples the reproducibility of the power loss values was found to be better than 1.5% and permeability within 5%.