Signedon metal plaque on front of case: WESTON ELECTRICAL INSTRUMENT CORP. / NEWARK N.J. U.S.A. / Model 440 No 5985
on paper scale: WESTON GALVANOMETER
Inscribedon metal plaque on front of case (serial number): 5985
marked on bottom "018"
on on scale: RES = 3.6 OHMS 1 DIV = 2.2 x 10^-6 AMP
FunctionThis portable pointer galvanometer is a sensitive instrument that was used for measuring current in the classroom. It consists of a coil with an attached needle suspended between the poles of a magnet. When an electric current is introduced into the coil, it induces a magnetic field, causing the coil to rotate in proportion to the current. This galvanometer was designed to be used in circuits where two currents are balanced against each other using a bridge or potentiometer until the scale reads zero. There are two push buttons on either side of the scale opening labeled "1" and "2." Button No 1 closes the galvanometer circuit through a high resistance to prevent damage if the circuits to be tested are considerably out of balance. No 2 closes galvanometer circuit directly to obtain maximum sensitivity.
ProvenanceFrom Department of Physics, Jefferson Laboratory, Harvard University, 1/19/1972.