FREMGANGSMAADE OG APPARAT TIL AT MAALE AFSTANDEN MELLEM SUCCESSIVE VINDINGER AF EN TRAAD, OPVIKLET SPIRALFORMET PAA ET LANGSTRAKT LEGEME

摘要

A method and apparatus for gauging the separation of successive turns of a wire helically wound on a fluid pervious, cylindrical body to form a wire screen for a subterranean well comprising the scanning of two adjacent wire turns after they are formed on the rotating cylindrical body with a video camera having a magnifying lens, projecting the resultant enlarged image of two adjacent wire turns on a video screen and simultaneously projecting on the same video screen parallel visible lines alignable with the amplified space between the two wire images, with the spacing of said parallel lines calibrated to represent a prescribed maximum and minimum tolerance dimension for the magnified spacing of the wire turns.