microammeter
Datecirca 1914
Inventory Number0469
ClassificationAmmeter
Subject
Maker
Robert W. Paul Instrument Company
1891 - 1919
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Place of Origin
Place of Use
Dimensions17.5 × 18.2 × 8.8 cm (6 7/8 × 7 3/16 × 3 7/16 in.)
Material
DescriptionAn ammeter consisting of a wooden case with a rounded, fan-shaped window for the instrument display. The display has a scale that goes from 0-10-120 amperes in intervals of 10. Over the scale moves a needle-shaped pointer with a circular loop midway along its length. There is a reflecting band under the scale.
The case has two electrical connectors, or binding posts on the front, and a round metal plate with a screw and an adjustment knob. Between them, inside an oval, is inscribed, "CLAMP FOR TRANSIT DEPRESS AND TURN," with an icon of an arrow. "UNIPIVOT" is stamped below the arrow.
Scale: 1-120 microamperes.
Resistance: 52.2 OHMS AT 20°C.
The case has two electrical connectors, or binding posts on the front, and a round metal plate with a screw and an adjustment knob. Between them, inside an oval, is inscribed, "CLAMP FOR TRANSIT DEPRESS AND TURN," with an icon of an arrow. "UNIPIVOT" is stamped below the arrow.
Scale: 1-120 microamperes.
Resistance: 52.2 OHMS AT 20°C.
Signedprinted on instrument display: MICROAMPERES / NO. KVI8 / RES. 52.2 OHMS AT 20° / ROBT. W. PAUL / LONDON / PATENTED;
on a metal plaque centered under the instrument display: Robt. W. Paul / 1. East 42nd Street / New York
FunctionAmmeter, for measuring electrical current in a circuit, in microamperes
ProvenanceRecovered from the Lyman Laboratory Attic, Harvard University, 2/2/65. Triangle indicates it was used in the Physics 3 course at Harvard.
Rawson Electrical Instrument Company
Date: circa 1930
Object number: 0428
Date: circa 1935
Accessories: four brochures for the Lightning Calculators, types A - D in library (Lib.4598a-d)
Object number: 1998-1-1349
Weston Electrical Instrument Corporation
Date: 1901-1930
Accessories: standardization certificate on inner surface of lid
Object number: 1997-1-1101
