| Abstract: | A non–stroboscopic system for freezing high speed rotational motion has been developed by WaddelI. The system depends on the fact that the image of a stationary object (e.g., turbine disc, crankshaft, grinding wheel) can be made to rotate accurately about one axis only (i.e., no oscillation which will blur the image) when the image is passed through a certain prism. The image of the object will rotate twice for one revolution of the prism. If the object now rotates, and a fixed velocity ratio is maintained between the object and the prism, the rotating image of the object is rendered optically stationary by the prism. The image is rendered stationary through 360 degrees of object rotation. A novel and inexpensive synchronising system has been evolved by Waddell to maintain a stationary image of the object for long periods and over a large range of speeds and to maintain that static image despite transients in the speed of the object. |
