DC galvanometer
Date: circa 1925
Inventory Number: 0427
Classification: Galvanometer
Subject:
Maker: General Radio Company (1915-present)
User: Department of Physics, Harvard University (founded 1884)
User: Cruft Laboratory, Harvard University (founded 1914)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
12.5 × 12 × 12.5 cm (4 15/16 × 4 3/4 × 4 15/16 in.)
Description:
A galvanometer in a wooden case, resting on four feet, with a wooden lid held in place by screws. The top of the instrument has a leather carrying strap, and the side has two bakelite binding posts.
The face of the instrument has a fan-shaped instrument display window, through which can be seen an instrument scale, marked from 1-100, and a knife-blade shaped indicator needle.
A metal cylindrical housing is mounted on the face of the instrument case, centered at the bottom. On top of the housing are two metal adjustment knobs, labeled, "ZERO SET" and "LOCK & FREE."
The face of the instrument has a fan-shaped instrument display window, through which can be seen an instrument scale, marked from 1-100, and a knife-blade shaped indicator needle.
A metal cylindrical housing is mounted on the face of the instrument case, centered at the bottom. On top of the housing are two metal adjustment knobs, labeled, "ZERO SET" and "LOCK & FREE."
Signedon instrument display: GALVANOMETER / TYPE 189A SERIAL NO. 17 / RES. 10 OHMS. FULL SCALE 121 MICRO AMPS / GENERAL RADIO CO. / CAMBRIDGE, MASS.;
Inscribedprinted on two metal adjustment knobs on instrument case: ZERO SET; LOCK & FREE;
FunctionGalvanometer, measures the electrical current in a circuit. For direct current.
Historical AttributesGreen triangle indicates it was used ibut green triangle indicates it was used in the student's labs at the Cruft Laboratory (Harvard) 1925.
Curatorial RemarksRes 10 Ohms Full scale 121 Microamps.
Zero adjust Lock free.
Zero adjust Lock free.
ProvenancePhysics Department, Harvard University. Found in Jefferson Laboratory, 1956.