摘要 |
929,715. Photo-electric gaugeing. M. C. PFISTER. Oct. 29, 1959 [Nov. 27, 1958], No. 4022/62. Divided out of 929,711. Class 40 (3). The width of an object is measured by scanning it in opposite senses by scanning heads as described in Specification 929,711, connecting the outputs in series, and measuring the sum output voltage with a self-balancing potentiometer. The axes of sensitivity of the scanning heads 54, 55, Fig. 3, are rendered perpendicular to the object 56 by a parabolic mirror 57. The outputs of the scanning systems 54, 55 are analogues of the distances X and Y so that the sum output equals G + b which, since G is constant, varies linearly with b. The outputs U54 and U55, Fig. 4, are connected in series and in opposition to a potentiometer 58 fed from a rectifier energized by the same mains as the scanning systems 54, 55. Any resultant current energizes a servomotor 61 to balance potentiometer 58. Servomotor 61 may also actuate an indicator or perform a process control. The object to be measured may be steel strip from a rolling mill or a rolled tube in which case scanning heads 54, 55 may be relatively displaced in the plane of Fig. 3. |