Currently indexing
standard non-inductive resistance, 1.0^6 Ohms
Date: late 19th-early 20th Century
Inventory Number: 0359
Classification: Resistance Standard
Subject:
Maker: Nalder Brothers & Company (founded 1884)
User: Department of Physics, Harvard University (founded 1884)
Cultural Region:
Place of Origin:
City of Use:
Dimensions:
4 × 7.5 × 22.5 cm (1 9/16 × 2 15/16 × 8 7/8 in.)
Material:
Description:
A high (10^6 W or 1.0^6 W) noninductive resistance is made by filling a groove on the underside of a hard rubber strip with graphite paint (!) Binding posts on top have their studs and nuts in the paint. The resistance material is protected by a sheet of hard rubber which becomes the base.
SignedEngraved on base: NALDER BROS & CO. / LONDON / NO. 3840
InscribedEngraved on base: 10^6 OHMS
FunctionA resistance standard of 10^6 ohms. Non-inductive resistances are meant to have negligible inductance, so they tend to be straight, short segments of relatively non-resistive materials.
Curatorial RemarksSee Provenance.
ProvenanceFrom Harvard University physics department. Blue triangle on instrument denotes its use for physics 3 course in the late 1920s.