| 摘要 |
An optical viewing tube having an eyepiece at one end and a viewing prism at an optical tip at the other end is provided with an optical system therebetween which will provide a focus for an object being viewed. A distance indicating disk or device on said tube is movable by a focusing mechanism to indicate the distance from the optical tip of the viewing tube to a viewed object. A camera is provided to be attached to the viewing tube to take a picture of the viewed object, and an eyepiece with a properly marked reticle is placed on the photograph taken, to indicate proper distances between spaced points on the object as seen in the photographs. The viewing tube is calibrated along its length so that tube penetration can be accurately known and a retention adapter is used with the tube to rigidly fix it in place. The retention adapter includes a compass rose which indicates the position of the viewing prism. An alignment adapter can also be used to insure proper alignment of the tube with a housing to which it is being connected. A modification of the tube has a focus numeral indicating device and an eyepiece containing a measuring device, with this modification the proper distance between spaced points on an object is obtained by obtaining a focus numeral from the indicating device and after obtaining units of distance between the spaced points from a measuring device, a divisional value for a specific reference numeral indicating unit size is multiplied by the number of units obtained from the measuring device to get the actual distance. |
