| 摘要 |
1,213,121. Measuring surface characteristics electrically. NATIONAL RESEARCH DEVELOPMENT CORP. Nov. 22, 1967 [Sept. 9, 1966], No.40304/66. Heading G1N. An electrically conductive body 11 whose surface characteristics e.g. roughness, it is desired to measure is brought into contact with an electrically conductive ball 14 of known surface characteristics which is suspended from an adjustable support 17, 18, a source of potential 22 is applied between the body and ball by closure of switch 24, and then a force sufficient to separate the ball from the body by overcoming the electrostatic attraction therebetween is applied by adjustment of support 17, 18. A measure of the force is determined by a displacement gauge 20 and is stated to be dependent on the surface characteristics of the body and ball, and the potential of source 22. In another arrangement, Fig. 2 (not shown), the body under test is disposed horizontally and contacted by a light cup-shaped member carried at the end of a pivoted rod, the other end of which may be subject to an adjustable, electro-magnetically applied force so as to lift the member away from the body after a potential difference has been applied between them. The cup-shaped member is formed of a smooth metal foil. A measure of the force is obtained from the current supplied to the electro-magnet. |
