Keuffel & Esser LO-VAR Surveyor's Tape

Description
This is marked "6285 TRADE LO-VAR MARK KEUFFEL & ESSER CO." and "NBS No 9228." With a coefficient of expansion of about .0000015 per degree Centigrade, Keuffel & Esser's LO-VAR tapes were said to be more stable than ordinary steel tapes that had a coefficient of expansion of .000016 per degree Centigrade. Keuffel & Esser also explained that since LO-VAR tapes were intended for precise base line measurements, they generally carry only the end marks and one or two intermediate marks. This example, however, is marked every 5 meters, and at 12.5 and 37.5 meters. It was tested by the National Bureau of Standards, and belonged to the U. S. Coast and Geodetic Survey. New, it cost $75.
Ref: Keuffel & Essser, Catalogue (New York, 1936), p. 535.
Location
Currently not on view
maker
Keuffel & Esser Co.
Measurements
overall length: 50 m; 164 1/32 ft
overall: 1 in x 18 in x 2 3/4 in; 2.54 cm x 45.72 cm x 6.985 cm
ID Number
1986.0395.14
accession number
1986.0395
catalog number
1986.0395.14
Credit Line
U.S. Department of Commerce, National Oceanic and Atmospheric Administration, National Geodetic Survey Division
See more items in
Medicine and Science: Physical Sciences
Measuring & Mapping
Surveying and Geodesy
Data Source
National Museum of American History

Comments

Add a comment about this object