Renseignements généraux

Nº de série

1293

Nº de partie

1

Nombre total de parties

1

Ou

S/O

Brevets

S/O

Description générale

Wood casing with metal control panel. Synthetic and metal controls. Synthetic galvanometer window.

Dimensions

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

Longueur

52,0 cm

Largeur

31,0 cm

Hauteur

20,5 cm

Épaisseur

S/O

Poids

S/O

Diamètre

S/O

Volume

S/O

Lexique

Groupe

Communications

Catégorie

Son

Sous-catégorie

S/O

Fabricant

Ou

Weston

Pays

United States of America

État/province

New Jersey

Ville

Newark

Contexte

Pays

Canada

État/province

Inconnu

Période

Inconnu

Canada

Taken from Acquisition proposal: Quoting from the NRCan web site: http://www.geod.nrcan.gc.ca/aboutus/gravity/grvinsts_e.php The Geodetic Survey Division owns and operates two absolute gravity instruments, JILA-2, and the A-10. It also collaborates with the GSC in the operation of a second instrument, FG5-106. The JILA-2 was acquired in November, 1985 and FG5-106 in April 1993. The A-10 instrument was acquired in 2000. The JILA-2 has been upgraded four times since it's acquisition with new computer control, new lasers, GPS clock and ancillary equipment. These upgrades were necessary in order to make it more efficient, field worthy, lighter and easier to use. Instrument modifications and tests are essential for Canada to remain at the leading edge in gravimetry. Because of their high accuracy of a few parts per billion, the instruments are used to establish, strengthen and expand the Canadian Gravity Standardization Net. Large calibration ranges are also established for the purpose of calibrating the complement of relative gravimeters owned by the Gravity and Geodetic Section. Smaller calibration ranges are maintained for industry so that companies can evaluate and compare their instruments against the established standard. Examples are the small calibration ranges between Ottawa and Gananoque and between Orangeville and Collingwood. The absolute gravimeters participate on a regular basis in international campaigns and comparisons in order to maintain the high standards of accuracy required of these instruments. The two most recent comparisons were done at the Bureau International des Poids et Mesures in Sevres, France, in 2001, and at Boulder, Colorado, USA, in 1995. The BIPM comparisons for instance occur every four years. Comparisons at the Canadian Absolute Gravity Site (CAGS) have been carried out every year with some exceptions since 1988 with the National Oceanic and Atmospheric Administration (NOAA) under an MOU.

Fonction

The 650 uses a "microphone hummer" as the ac oscillator to drive the bridge circuits. With headphones, used to detect the null balance.

Technique

These items have all played a role in Canada's position at the leading edge of gravimetry. Obviously the leading edge of 30 years ago is no longer the leading edge so NRCan has upgraded its instruments on a regular basis.

Notes sur la région

Inconnu

Détails

Marques

Print reads: "IMPEDANCE BRIDGE/ TYPE 650-A SERIAL NO. 1293/ GENERAL RADIO CO./ CAMBRIDGE MASS. U.S.A."/ Gauge reads: "GALVANOMETER/ GENERAL RADIO CO./ MF'D BY/ WESTON ELECTRICAL INSTRUMENT CORP, NEWARK, N.J. U.S.A."/

Manque

S/O

Fini

Wood stained brown. Black textured covering on control panel. Black synthetic controls. Plated and metallic parts. Black painted metal dials. Clear window over gauge.

Décoration

S/O