General Information

Serial #

M8608

Part Number

1

Total Parts

2

AKA

Mercury triple point temperature standard

Patents

N/A

General Description

metal casing, control panel, handles, parts/ synthetic knob, panel, power cord, parts/ rubber? corks

Dimensions

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

Length

60.0 cm

Width

49.0 cm

Height

98.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Metrology

Category

Temperature

Sub-Category

N/A

Manufacturer

AKA

YSI

Country

United States of America

State/Province

Ohio

City

Yellow Springs

Context

Country

Canada

State/Province

Ontario

Period

Unknown

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

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

Technical

An example of a temperature standard used in a laboratory for the calibration of meteorological thermometers. In 2006, both Isothermal Technology Ltd. of England and YSI Temperature of the U.S. still offered the model 17725 temperature standard and the 17725 mercury cell for sale (Ref. 1-2). A triple point is the temperature and pressure at which the gaseous, liquid and solid phases of a given substance coexist at equilibrium. The triple point of mercury is.-38.8344°C. at a pressure of 0.2 mPa. (Ref. 3-4) This apparatus is a free-standing, self-contained mechanically refrigerated cryostat. The mercury cell (2004.0324.2) is placed in its well, which is operated in the form of an essentially gradient-free heat pipe. A unique control system provides a precise means for regulation of the cell and well temperature over the range from -36 °C to -42 °C, allowing the mercury triple point to be approached optionally from the freezing or melting direction. Two auxiliary wells are pre-chilling thermometers to be calibrated. The cell containment is a plasma-arc welded stainless steel shell. The mercury contained has impurities of less than 15 parts per billion. The purity of the metals such that triple point plateaux are flat to 100 microkelvins (0.0001 °C) (Ref. 2).

Area Notes

Unknown

Details

Markings

incised black lettering on front plate reads 'YSI MODEL 17725/ MERCURY TRIPLE POINT/ TEMPERATURE STANDARD/ (Requires YSI Model 17724 Mercury Triple Point Cell)/ [logo reading YSI] YSI Incorporated/ Yellow Springs, Ohio 45387 USA'/ label on back reads 'YSI Incorporated YELLOW SPRINGS INSTRUMENT CORP. INC./ YELLOW SPRINGS, OHIO 45387-0279 USA/ Model 17725 Sn M8608/ V 110 A 15 Hz 60'/ black synthetic label on synthetic top panel reads '-38.84041/ ITS90 -38.8331'

Missing

unknown - appears complete

Finish

glossy dark grey painted casing/ brushed metal control panel plate on front with black synthetic knob and brushed metal handles/ textured grey synthetic panel on top with two black rubber corks/ black power cord

Decoration

N/A