The design features of an automatic oscillograph reader

The Northrop oscillograph reader is an automatic device designed and built to eliminate the previously laborious task of reducing data gathered from telemetering and other engineering tests. Most of the members of this convention are in fields of engineering that require oscillographic recording as a means of capturing data. It is assumed that most engineers are familiar with the old inaccurate system of sharpened pencils and fifty division to the inch rulers and to the era of data reducers with the so called calibrated eyeballs. The procedure in reducing an oscillograph record is to determine the displacement of each trace from a reference line and store this information so that at a later time, by means of a previously determined calibration curve, the displacement can be converted into terms of the original input variable. Recently, several companies have brought forth devices employing manually operated movable crosshairs to represent the two coordinates of deflection and time. These employ analogue-to-digital converters to record the observed data on tabulators or punched cards. While these later machines have a great deal of appeal to the data reducer, any large amount of data to be reduced still represents a very tedious job with accuracies depending for the most part on the physical condition of the operator. In order to produce results from a large amount of data with extreme accuracy, the automatic reader was developed. Initial work was started in October, 1953 and completion took place by October, 1954.