resistance standard (0.1 Ohm)
Date: 1903-c1930
Inventory Number: 2007-1-0108
Classification: Resistance Standard
Subject:
Maker: Leeds & Northrup Company (1903 - 1995)
User: Jefferson Physical Laboratory, Harvard University (founded 1884)
User: Department of Physics, Harvard University (founded 1884)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
16.2 × 8.5 × 17.5 cm (6 3/8 × 3 3/8 × 6 7/8 in.)
Material:
Description:
Coil of manganin wound on a tube supported in a perforated nickel-plated case with a hard rubber top. Four terminals, all with adjustment knobs with knurled-edges, protrude from the hard rubber top; (2) are "L" shaped, and (2) are post-style. Ther hard rubber top has cylindrical center knob.
Signedstamped on top: The Leeds & Northrup Co. / Philadelphia
Inscribedinscribed on top: THE LEEDS & NORTHRUP CO. / PHILADELPHIA / 25407
FunctionFor suspension in mercury to a standard bridge set in an oil bath.
A resistance standard is not to measure the resistance of an electric conductor but rather to compare such a conductor to a temperature-fixed resistance. In other words, such a device is used to determine the value of an unknown current. To do so, a current in the conductor would pass through mercury (for the older type of standard resistance), into which the two leads from the resistor dip.
A resistance standard is not to measure the resistance of an electric conductor but rather to compare such a conductor to a temperature-fixed resistance. In other words, such a device is used to determine the value of an unknown current. To do so, a current in the conductor would pass through mercury (for the older type of standard resistance), into which the two leads from the resistor dip.
Curatorial Remarksobjects 2007-1-0108, 2007-1-0109, 2007-1-0110 were likely stored together and were used at the same location.
ProvenanceTriangle indicates it was used for the Physics 3, Jefferson Laboratory, Harvard University.
