Signedon face of right meter: 62 / OHMS PER UNITS / WESTERN ELECTRICAL INSTRUMENT CO., NEWARK, N.J., U.S.A. / MODEL 301 NO. 966071
on face of left meter: 62 / OHMS PER UNITS / WESTERN ELECTRICAL INSTRUMENT CO., NEWARK, N.J., U.S.A. / MODEL 301 NO. 882620
FunctionThis is a custom-built electrocardiograph that contains two identical recording systems mounted on the same table. The main components are the string galvanometers that are mounted on top. Each of them consists of a pair of electromagnets, arranged to have a small vertical space between them through which a thin metal wire ("string") passes. This wire is part of a circuit and carries a current proportional to the imput signal recorded from the patient. A light source would cast a shadow from this string onto a photographic recording mechanism at the opposite end of the lense arrangement.
A dual electrocardiograph would allow to make a simultaneous recording originating from different signals, usually of the same patient.
Historical AttributesElectric cardiograph especially built for Dr. Paul Dudley White and Dr. Howard Sprague, c. 1940, by the Sanborn Company.
ProvenanceGiven by Dr Howard S Sprague, April 26 1969.