| 摘要 |
1,071,683. Detecting flaws. LORRAINEESCAUT and LABORATOIRES D'ELECTRONIQUE ET D'AUTOMATIQUE DU NORD "LEANORD". June 1, 1964 [Oct. 21, 1963], No. 22515/64. Heading G1N. Flaws in rolled metallic products are detected by applying a high frequency field perpendicular to the thickness and measuring magnetic leakage at the other side of the product. As shown, differentially connected coils BE 1 , BE 2 surrounding a moving tube T produce a field in the radial plane P. Differentially connected pick-up coils BR 1 , BR 2 receive pulses when a flaw passes and operate a warning device through an amplifier and relay. The circuit may include a guard circuit to prevent actuation at the end of a tube. The signals may be stored. |
