Abstract: An improved high speed photographic data plotting system is disclosed. This system uses a modulated laser light which is moved or scans a photographic film on a concave cylindrical surface from source location on a central axis. The scan is in a direction transverse to the length of the film. The laser light source location on the central axis can be incrementally stepped between each scan so that exposure of the film is in lines along the length of the film. The system includes means for feeding a film to a concave surface, means for securing the film to the surface, and means for cutting the film into a segment. The laser light source is exterior to the photographic chamber and the light beam is modulated and is transmitted along a central axis onto a rotating surface (source location) which projects the light beam normal to the central axis and onto the film.

Abstract: Disclosed is a system for monitoring the speed at which a pipe string is lowered into or pulled out of a well bore during a well drilling operation. The system includes a unit which derives an electrical signal as a function of instantaneous pipe speed and a monitoring system which compares signals representative of instantaneous velocities with respect to predetermined velocity limits and provides physiological indications whenever such limits are transgressed. Also included are visual indicator means and recorder means, as well as a loop control system for automatic regulation of the speed.