GB786817A - Improvements in and relating to apparatus for the measurement of magnetic flux - Google Patents

Abstract

786,817. Flux meters. BRUSH ELECTRICAL ENGINEERING CO., Ltd. Sept. 16, 1965, No. 26532/55. Class 37. Apparatus for the measurement of magnetic flux comprises a narrow probe composed of a central conductor member disposed between and laterally displaceable in relation to two outer conductor members. As shown, probe g, Fig. 3, inserted in test flux Hy, Fig. 1, consists of a central conductor c and fixed outer conductors a. A steady current Iz in central conductor c produces a field which interacts with test flux Hy to cause deflection of central conductor c. As shown in Fig. 4, the conductors a, c are encircled by an insulating sheath hand are mutually separated by insulating pads i whilst an earthed screen surrounds sheath h. Also conductors a, c are suitably connected to a supply circuit via double screened leads e, Fig. 3, so that with c earthed and fixed at both ends force Fx produces curvature deflection of c and thus change in capacitance of outer conductors a to earth. The change in capacitance is measured by an electronic circuit (not shown) and depends on the value of the applied field Hy and direction of motion of inner member c so that in one position a capacitance meter has a maximum reading and when probe g is rotated from this position through 90 degrees the reading is a minimum; thus by suitable calibration and orientation probe g will detect the value and direction of the flux. The measuring circuit may comprise an oscillograph which indicates transient or periodic variations in flux Hy.