Dial-reading translator for digital machine inputs

THE OPERATING COST of large transonic wind tunnels, such as the Southern California Co-operative Wind Tunnel (CWT), is so high that it is important that the data be recorded as quickly and efficiently as possible without sacrificing reliability. The time-consuming task of permanently recording the many measurements required during the testing of modern airplanes has led to the recent development of several automatic recording devices which read the position of a force-measuring instrument, translate the reading into a whole number, and then print the number on a data sheet. None of these devices seemed to be suited particularly to the reading of the potentiometers which are currently used at the CWT for indicating forces by means of resistance strain gauges mounted on small balances within the model.