| 摘要 |
<p>1. A device for detecting by eddy currents defects in a metal product travelling in front of at least one sensor (1a to 1d), this device being adapted to be integrated in a straightening machine having two rollers, one of which is a hyperbolic roller (9), said at least one sensor comprising two windings (7, 6) in series disposed at different distances from the product (2), a field winding (5) disposed in such manner as to produce in the two windings opposed magnetic fields, means for detecting the voltage (V) at the terminals of these two windings, and an electronic circuit (16 to 40) for detecting the variation of the argument (theta) of the vector representing this voltage relative to the field voltage vector (vphi), characterised in that the sensor (1a to 1d) is embedded in a guide bar (10) of said straightening machine, this bar being in confronting relation to the direction of rotation of the hyperbolic roller (9) and is protected by an interchangeable member (12).</p> |
