Scanning system for calculation of profile areas - has synchronised motor driven laser and detector with electronic counter

摘要

The contour scanning system for determining the surface areas of profiles is suitable for investigations on aerodynamic models. The model stands on a support platform (1) at each end of which, at right angles is a vertical frame comprising upright posts (6) and a cross bar (12). A horizontal guide rail (15) supports a slide to which is attached a laser light source (27). The laser is made to traverse the width of the frame by a reversing motor drive shaft (21). The guide rail is moved vertically be means of a stepping motor (10) and vertical feed screws (8,9). A similar frame at the other end of the model carries a photo-detector driven in a similar fashion and synchronised with the moving laser. An electronic counter gives an output during the scan when the laser beam is interrupted by the model's 'shadow' to provide a measurement of the profile area.