COORDINATE READER AND CARD PUNCH OR TABULATOR,
JOHNS HOPKINS UNIV SILVER SPRING MD APPLIED PHYSICS LAB
Pagination or Media Count:
The equipment was designed to be used in either of two modes as dictated by the requirements of the information which is to be transcribed. The first mode is one of reading relative values of coordinates which are randomly or otherwise scattered about, such as particles in a fluid. The positions of the particles may change as a function of time, and the successive readings will show their behavior and can be mathematically analyzed. This may be recorded on a number of successive single-exposure frames of a photographic film, or on one frame with successive exposures. In each of these cases both coordinate values are unknown. In the second mode, readings are made at prescribed intervals along one axis, such as in the conversion of strip-chart records and oscillograph records to punched cards, where equal steps along one usually the horizontal axis are desired the position of the other coordinate being the intersection of the first one and the recorded trace. Initial read-out of calibration traces allows an interpolation by machine calculation which produces linearized data.
- Computer Hardware