| 摘要 |
<p>The current probe has four active windings(10a - 10d) whose shape and electromagnetic characteristics are sensibly identical. They have their geometric centres(12a - 12d) arranged in a square situated in a plane designed to be oriented parallel to a face of a piece to be tested. The principal geometric axes(18a - 18d) pass through a point(19) situated on a normal to this plane passing through the centre of the square, or parallel to this normal. The windings(10a,10c; 10b,10d) whose geometric centres are at the opposite tops of the square are connected in series in pairs, so as to produce magnetic fields which are summed along each diagonal of the square, when a current is passed through the windings. The windings(10a - 10d) are connected to a supply source(20) so as to form an emitter. The two nearest windings of this emitter are connected to each other differentially and are connected to a measuring device(22) so as to form a receiver. The fourth active winding is unused.</p> |
