standard milli-voltmeter
Datecirca 1925
Inventory Number0531a
ClassificationVoltmeter
Subject
Maker
Weston Electrical Instrument Corporation
founded 1888
User
Lyman Laboratory of Physics, Harvard University
founded 1931
User
Department of Physics, Harvard University
founded 1884
Cultural Region
Place of Origin
Place of Use
Dimensions11.2 × 39 × 35.8 cm (4 7/16 × 15 3/8 × 14 1/8 in.)
Material
Accessoriesshunt (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)
DescriptionA Weston voltmeter, housed in a fan-shaped brass case, mounted on a rectangular walnut base. The Voltmeter has an arc-shaped display window, through which may be seen an arc-shaped scale, above an arc-shaped mirror strip and moveable knife-edge indicator needle. The instrument is a permanent-magnet moveable-coil type.
Alongside the metal housing on the base is a glass thermometer.
The wooden base has a spirit level, two bakelite binding posts, one of which marked "+," and press button.
Alongside the metal housing on the base is a glass thermometer.
The wooden base has a spirit level, two bakelite binding posts, one of which marked "+," and press button.
Signedscroll-shaped plaque on the instrument's face is inscribed: WESTON DIRECT READING LABORATORY STANDARD / MILLI-VOLTMETER / WESTON ELECTRICAL INSTRUMENT CO. / MANUFACTURERS NEWARK, N.J. U.S.A. / PATENTED / NOV. 6 1888 NO 342306 & NO. 392307 MAY 14 1889 NO. 403311 / APR. 29, 1890 NO. 426992 & NO. 427022 JUNE 10, 1890 / NO. 19895 & NO. 19096 / NO. 90.
Inscribedslip with accessories: (front) 531 / Weston No. 90 / (reverse) both out / and in / also shunt!
Curatorial RemarksWas first incorreclty catalogued as 1997-1-0219a, so slide shows it with that number.
FunctionThis is a standard voltmeter, for callibration. Hence its high accuracy of 1/10 of 1%. A thermometer is included to guarantee measurements at the right temperature.
ProvenanceWas originally part of new standards room, Lyman Laboratory, Harvard University, ca. 1935.
Brought to the collection from the Jefferson Physical Laboratory, Physics Department, Harvard University, 4/27/1970. Blue triangle indicates it was used in the Physics 3 course.
Historical AttributesThis instrument wsa originally part of new standards room, Lyman Laboratory, Harvard University, ca. 1935.
Weston Electrical Instrument Corporation
Date: circa 1921
Accessories: petri dish (1997-1-1059b) containing three loose binding posts, short lengths of wires, and an array of small mismatched screws, bolts, and washers
Object number: 1997-1-1059a,b
Weston Electrical Instrument Corporation
Date: 1911
Accessories: shunt (0438b)
Object number: 0438a
Weston Electrical Instrument Corporation
Date: late 19th Century
Accessories: two shunts (#0270b and #0270c); special leads
Object number: 0270a
Weston Electrical Instrument Corporation
Date: circa 1914
Accessories: multiplier in case of instrument; standardization certificate from the Weston Laboratory, Newark, N.J. Feb.1914 on lid of wooden case
Object number: 0278
Weston Electrical Instrument Corporation
Date: late 19th Century
Accessories: petri dish attached containing small parts and paper reading: "531; Weston no. 90"
Object number: 0270c
Siemens & Halske AG
Date: circa 1910
Accessories: seven shunts (0560b-h)
Object number: 0560a
Weston Electrical Instrument Corporation
Date: 1900-1917
Accessories: wooden instrument case (0526d); shunts (0526b and 0526c)
Object number: 0526a
Siemens & Halske AG
Date: circa 1900
Accessories: wooden carrying case; instrument testing report by Siemens & Halske's New York office, 1913
Object number: 0276a,b
Weston Electrical Instrument Corporation
Date: 1894
Accessories: Weston portable multiplier (0279b); standardization certificate on back of lid
Object number: 0279a
See also/See also
