General Information

Serial #

391

Part Number

1

Total Parts

2

AKA

N/A

Patents

N/A

General Description

metal and synthetic

Dimensions

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

Length

16.0 cm

Width

16.0 cm

Height

29.0 cm

Thickness

N/A

Weight

N/A

Diameter

N/A

Volume

N/A

Lexicon

Group

Physics

Category

Geophysics

Sub-Category

N/A

Manufacturer

AKA

Texas Instruments

Country

United States of America

State/Province

Texas

City

Houston

Context

Country

Canada

State/Province

Unknown

Period

Purchased by NRCan 01/11/1955

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.

Function

Instrument used in Geophysical Exploration to measure the earth's gravitational field.

Technical

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.

Area Notes

Unknown

Details

Markings

Mfr's plate reads: "WORDEN GRAVITY METER/ SERIAL NO. 391/ TEXAS INSTRUMENTS INCORPORATED/ INDUSTRIAL INSTRUMENTATION DIVISION/ MADE IN U.S.A./ HOUSTON, TEXAS/ PAT 2,674,887"/ White label below with black print and red Canada flag logo: "[Canadian flag logo]/ NRCan/ RNCan/ A051018/ [bar code]"/ Black label with black print: "GR 62007", red print reads: "DO NOT REMOVE THIS TAG"/ Black label with silver print: "DIAL CONSTANT/ .3998 (7) [print in yellow]/ MILLIGALS [/] DIVISION"/ Yellow label with red print reads: "CAUTION/ RADIOACTIVE/ MATERIAL"/

Missing

RADIO ACTIVE; ARTIFACT NOT MARKED WITH CATALOGUE NUMBER.

Finish

Silver metal and black synthetic.

Decoration

N/A