PORTABLE PHOTOELECTRIC DISPLACEMENT MEASURING INSTRUMENT

• Main Authors: YAMAZAKI IWAO, IMAI HIROMICHI
• Format: Patent
• Language: English
• Published: 22.04.1991
• Subjects: ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVEREDIN A SINGLE OTHER SUBCLASS; MEASURING; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS; MEASURING LENGTH, THICKNESS OR SIMILAR LINEARDIMENSIONS; MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR; PHYSICS; TARIFF METERING APPARATUS; TESTING

PURPOSE:To prevent an external magnetic field from entering an image desector tube by composing a magnetic shield cases of an external cylinder and an internal cylinder which are arranged concentrically with each other, a top lid which has a projection part at an opening where light is made incident, and a bottom lid, and providing a separator between the two cylinders. CONSTITUTION:The shield case 6 consists of the external cylinder 70 and internal cylinder 71 which are arranged concentrically and the top lid 72 and bottom lid 74 are inserted and fixed to the external cylinder 70 on both ends. There is the opening 15 for guiding the external light to the inside in the center of the top lid 72 and the cylindrical projection part 73 which projects outward axially is formed at the source location. A gap 78 which maintains a specific gap is interposed between the external cylinder 70 and internal cylinder 71. Then, supports 11 and 11' are inserted into the internal cylinder 71 and brought into contact with each other to fix the image desector tube 10 to the magnetic shield case 6. Consequently, the external magnetic field is prevented from entering the image detector tube 10.