DC galvanometer
Datecirca 1925
Inventory Number0427
ClassificationGalvanometer
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
Place of Use
Dimensions12.5 × 12 × 12.5 cm (4 15/16 × 4 3/4 × 4 15/16 in.)
Material
DescriptionA 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
Curatorial RemarksRes 10 Ohms Full scale 121 Microamps.
Zero adjust Lock free.
FunctionGalvanometer, measures the electrical current in a circuit. For direct current.
ProvenancePhysics Department, Harvard University. Found in Jefferson Laboratory, 1956.
Historical AttributesGreen triangle indicates it was used in the student's labs at the Cruft Laboratory (Harvard) 1925.
Weston Electrical Instrument Corporation
Date: 1911
Accessories: shunt (0438b)
Object number: 0438a
Rawson Electrical Instrument Company
Date: circa 1930
Object number: 0428
Weston Electrical Instrument Corporation
Date: circa 1925
Accessories: shunt (0531b); box of 6 screws, two modified bolts, and one small piece of wood (all these originally housed in petri dish, now transferred to archival box)
Object number: 0531a
Weston Electrical Instrument Corporation
Date: 1900-1917
Accessories: wooden instrument case (0526d); shunts (0526b and 0526c)
Object number: 0526a
