DIGITAL READER OF OSCILLOSCOPE TRACE PHOTOGRAPHS

A device for reading ordinary Polaroid oscilloscope trace photographs has been assembled from an oscilloscope, an oscilloscope camera, a 400 channel analyzer, and some control circuitry. This device reads the coordinates of 400 points along a trace by scanning in the y direction until the trace is found for each of 400 x positions. A photomultiplier tube looking through the back of the Polaroid print detects the trace. The reading, which is stored digitally in the analyzer until printed out, has an accuracy of better than 1%. This technique can be adapted to other types of trace photographs and can use other digital devices as well. © 1968 The American Institute of Physics.