General Information

Serial #

1639537

Part Number

1

Total Parts

3

AKA

resistance thermometer

Patents

N/A

General Description

glass tube/ metal handle, wiring and connectors/ synthetic wire covering and parts

Dimensions

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

Length

57.0 cm

Width

N/A

Height

N/A

Thickness

N/A

Weight

N/A

Diameter

2.5 cm

Volume

N/A

Lexicon

Group

Metrology

Category

Temperature

Sub-Category

N/A

Manufacturer

AKA

Leeds Northrup

Country

United States of America

State/Province

Pennsylvania

City

Philadelphia

Context

Country

Canada

State/Province

Ontario

Period

Unknown

Canada

An instrument used in the Calibration Unit of the Instrument Division of the Meteorological Branch of the Department of Transport of the Government of Canada. The Meteorological Branch became the Atmospheric Environment Service in 1971 and so this instrument was probably manufactured before that date. 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

An instrument used in a meteorological instrument laboratory to calibrate thermometers.

Technical

An example of a standard platinum resistance thermometer. The model number of this Leeds and Northrup Thermohm is not marked on the thermometer but the case in which it is stored is labelled ‘8163 Platinum Resistance Thermometer'. Leeds and Northrup's 1940 and 1946 catalogues list the 8163 platinum resistance thermometer with a range of -19- to +500 Celsius; resistance about 25.5 ohms at O degrees; resistance change about 0.1 ohm per degree C.; Pyrex tube, 0.7 cm diameter, extends about 46 cm from head; sensitive portion about 2 cm long; four lead cable. This precision resistance thermometer was marketed for use with a temperature bridge (Refs. 1-2). In 1981 YSI acquired the rights to make the 8163 thermometer and was still marketing it in 2007 as a traditional standard platinum resistance thermometer, the world's working standard of temperature. It measures from -200 to +500 Celsius with a 6 second time constant (Ref. 3). In 2007 Isotech also was offering YSI's standard platinum resistance thermometer: the sensor element consists of a bifilar coiled coil of platinum. According to Isotech, this thermometer is a direct descendent of those developed by C.H. Meyers of the National Bureau of Standards in the early 1930's. Later Meyers transferred his business to Leeds and Northrup where they were produced for many years (Ref. 4).

Area Notes

Unknown

Details

Markings

white lettering on handle reads 'THERMOHM/ LEEDS & NORTHRUP CO./ PHILADELPHIA/ 1639537/ MADE IN U.S.A.'

Missing

appears complete

Finish

colourless transparent glass/ black crinkle painted handle/ black wire covering/ plated and gold coloured metal parts

Decoration

N/A