Equipment and materials

The Talydata graphical display system and modular electronics and recorders for use on all future RPI Talyrond roundness measuring instruments comprises a small, very fast, dedicated computer. Contained in just a few printed circuit boards, it will perform all the calculations needed to display the roundness graph on a cathode ray tube, and to display simultaneously either the least squares circle, or inscribed or circumscribed circles, or the minimum zone circles. During the first revolution of the measuring table signals from the measuring probe are fed into the computer store and a display obtained if required. During the second, the calculations made and applied to centre the workpiece; and a third revolution is required to obtain the centred least squares circle, or whatever measuring parameter is selected by pushbutton, displayed superimposed on the roundness graph. The graphical display means that in routine inspection applications the conventional paper disc polar graph need only be produced when something unusual is shown on the display.