Renseignements généraux

Nº de série

S/O

Nº de partie

1

Nombre total de parties

14

Ou

U-TUBE

Brevets

S/O

Description générale

STAINLESS STEEL

Dimensions

Remarque : Cette information reflète la taille générale pour l’entreposage et ne représente pas nécessairement les véritables dimensions de l’objet.

Longueur

S/O

Largeur

S/O

Hauteur

S/O

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Météorologie

Catégorie

Mesure de la pression atmosphérique

Sous-catégorie

S/O

Fabricant

Ou

MSC

Pays

Canada

État/province

Inconnu

Ville

Inconnu

Contexte

Pays

Canada

État/province

Ontario

Période

LATE 1950'S UNTIL AT LEAST C. 1970

Canada

CANADIAN DESIGNED & BUILT STANDARD BAROMETER USED AS CANADIAN PRIMARY STANDARD BAROMETER BY METEOROLOGICAL SERVICE OF CANADA.

Fonction

A SPECIALLY CONSTRUCTED INSTRUMENT THAT MEASURED ATMOSPHERIC PRESSURE & WAS USED AS CANADA'S PRIMARY BAROMETER, THAT IS, THE BAROMETER BY WHICH OTHERS ARE CALIBRATED (1).

Technique

U-TUBE BAROMETER DESIGNED BY BINDEN & VOCKEROTH AS MSC PRIMARY BAROMETER; IT HAD INVAR PROBES (WITH STEEL POINTS, GRATICULES, & REFECTING PRISMS) PROJECTING INTO TUBES, LIGHTS ON ENDS OF SEPARATE RODS, SCALES OBSERVED BY TELESCOPES, & HAD AN ACCURACY OF 20 MICRONS (REF. 1). THE BAROMETER CONSISTED ESSENTIALLY OF A STAINLESS STEEL U-TUBE OF 3 INCH I.D. THE TOPS OF THE ARMS OF THE U-TUBES WERE CAPPED AND THE HEIGHT DIFFERENCE OF THE FREE MERCURY SURFACES ON THE HIGH VACUUM ARM AND THE TEST PRESSURE ARM ARE WAS MEASURED DIRECTLY BY INVAR PROBES WHICH WERE INTRODUCED VERTICALLY INTO THE ARMS BY O-RING SEALS. PROVISION WAS MADE FOR TO OBSERVE THE COINCIDENCE OF THE MERCURY POINTS ON THE MERCURY SURFACE VISUALLY. THE DECISION ON THE EXACT SETTING OF THE POINTS ON THE SURFACE WAS MADE BY OBSERVING THE DISTORTION OF THE REFLECTION OF A GRID OF STRAIGHT LINES CAUSED BY THE DEFORMATION OF THE MERCURY SURFACE ON THE ENTRY OF THE PROBE POINT. THE PROBE ARMS WERE GRADUATED IN MILLIMETRES & THE HEIGHT DIFFERENCE BETWEEN THE FREE SURFACES OF THE MERCURY WAS MEASURED BY MEANS OF TWO MICROMETER TELESCOPES FIXED ON A STEEL PILLAR. THE ZERO DIFFERENCE BETWEEN THE POINTS WASW ESTABLISHED BY ALLOWING THE TWO FREE MERCURY SURFACES TO FORM A LEVEL SURFACE BY EQUALIZING THE PRESSURE IN BOTH ARMS. THE MEAN TEMPERATURE OF THE MERCURY COLUMN WAS ESTIMATED BY A SERIES OF 10 TEMPERATURE PROBES SPOTTED AT EQUAL INTERVALS THROUGHOUT THE MERCURY COLUMN. IT WAS ESTIMATED THAT THE PRESSURE COULD BE DETERMINED TO AN ACCURACY OF 20 MICRONS IN THE ROUTINE USE OF THIS STANDARD. (REF. 2).

Notes sur la région

Inconnu

Détails

Marques

NONE

Manque

LATHE BEDS, OTHER PARTS From CA of 11/03/1993 by Tony Missio: Undetermined According to MSC meteorologist (Oct. 2007), this artifact comprises only a portion of the original barometer and is missing a good part of its ancillary contstruction.

Fini

STAINLESS STEEL

Décoration

S/O