Images(4)

portable galvanometer with moving coil

Datecirca 1920

Inventory Number0217

ClassificationGalvanometer

Subject

Maker Leeds & Northrup Company 1903 - 1995

User Department of Physics, Harvard University founded 1884

Cultural Region

Place of Origin

Place of Use

Dimensions11.5 × 12.7 × 6.5 cm (4 1/2 × 5 × 2 9/16 in.)

Material

DescriptionPortable galvanometer with four moveable pancake coils attached to pointer and located within a fixed rectangular magnet housed in rectangular wooden case. Case has three binding posts above circular glass window for viewing the scale and pointer. Scale is unlabeled.

Signedon metal plate above scale: THE LEEDS AND NORTHRUP Co. / SCIENTIFIC INSTRUMENTS / PHILADELPHIA / 6350

FunctionThis portable pointer galvanometer is a sensitive instrument that was used for measuring electric current. It was most likely used by students at Harvard. 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.

ProvenanceFrom the Department of Physics, Harvard University, 12/11/1956.