tangent galvanometer with moving magnet
Date1900-1910
Inventory Number0195a-e
ClassificationTangent Galvanometer
Subject
Maker
Edelmann
fl. 1880 - 1920
Cultural Region
Place of Origin
Place of Use
Dimensions29 × 50 × 18 cm (11 7/16 × 19 11/16 × 7 1/16 in.)
Material
DescriptionGalvanometer with paper scale encased in cylindrical glass case with vertical brass suspension tube mounted on wood and brass support set in a track (0195d). Two removeable coils also slide in this track. One coil with many turns of fine wire (0195b) and other coil with one turn of copper strapping (0195c). Brass scale (0195e) graduated from 0-30 cm mounted on one side of the track. Rectangular wooden base (0195a) with two leveling screws on one end (two missing from other end) and two binding posts.
Signedon paper scale: Dr. Edelmann, München
on brass scale: EDELMANN / MÜNCHEN QUEEN & CO. AGENTS
Inscribedtagged "G.L. Anderson"; tagged "G.L.A." twice and stamped "GLA" 3 times.
Curatorial RemarksCataloged by Lew Law 2/23/95; re-cataloged 7/24/97. Paper scale marked "Dr. Edelmann, München" brass scale marked "Edelmann, München, Queen & Co, Agents" Old Nos: tagged "G L Anderson", tagged "GLA" twice, and stamped GLA three times
FunctionA tangent galvanometer measures the strength of an electric current. It has a circular coil with a turn of wire and a magnetic needle at the center that is either balanced on a point or suspended by a fiber of silk or quartz. The meter has to be first aligned in the north-south direction and thus the instrument takes into account the earth's magnetic field. When a current is sent through the coil, the needle is deflected according to the vector sum of the field produced by the earth and by the unknown current in the coil. The tangent of the needle's angle of deflection is proportional to the strength of the unknown current producing it.
For more information, go to the following website.
For more information, go to the following website.
ProvenanceFrom the Department of Physics, Harvard University, 11/23/1956.
Department of Physics, Harvard University
Date: circa 1893
Accessories: extra scale (0190b)
Object number: 0190a
