General Information

Serial #

137AU

Part Number

1

Total Parts

2

AKA

N/A

Patents

N/A

General Description

invar

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

102.2 cm

Width

2.5 cm

Height

2.6 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Meteorology

Category

Miscellaneous

Sub-Category

N/A

Manufacturer

AKA

GAERTNER

Country

United States of America

State/Province

Illinois

City

Chicago

Context

Country

Canada

State/Province

Ontario

Period

Unknown

Canada

A piece of equipment used by the Meteorological Service of Canada. Part of a large collection of meteorological instruments acquired from the Meteorological Service of Canada (previously Atmospheric Environment Service) by the CSTM since 1967. MSC is the government agency responsible for collecting and disseminating meteorological data and forecasts in Canada. It was founded in 1871 in Toronto where it is still headquartered. The MSC was originally on the University of Toronto downtown campus but moved to Downsview in 1971 on land owned by UofT. The headquarters houses laboratories, research facilities and calibration and instrument maintenance facilities (now largely contracted out).

Function

A precise measure of length, based upon a government standard & used as a standard against which commercial & other measures could be verified.

Technical

An example of a precise rule made to be used to check that standards established were maintained in science and industry. This example is made of invar, an iron-nickel allow with an extremely low coefficient of expansion at temperatures ranging from cryogenic to ambient. Invar's almost non-existent expansion in response to temperature changes made it very useful for length standards (Ref. 2). Gaertner Scientific Corp. of Chicago was incorporated in 1923 . In 1969 Gaertner was sold to American Machine and Science Inc. of Elgin, IL and again in 1978 to its present owners. The company has since relocated to newer facilities in Skokie, IL (Ref. 1). This standard length was thus manufactured between 1923 and sometime after 1978.

Area Notes

Unknown

Details

Markings

incised lettering reading 'GAERTNER Scientific Corporation CHICAGO SERIAL NO. 137AU.' and 'INVAR COEFFICIENT OF EPX. = 2.0 X 10 (-6) PER DEG. C.'

Missing

appears complete

Finish

brushed

Decoration

N/A