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Subtense Bar - click to enlarge

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Subtense Bar

Catalogue number:
1996.0186.02

Inscriptions:
"WILD HEERBRUGG SWITZERLAND No. 86845"

Dimensions:
length 2 meters

Discussion:

A subtense bar is a bar of known length, with targets at either end. It is usually made of a stable material such as invar. When used with a theodolite, it serves as a quick and convenient method of measuring distances indirectly. The subtense technique is similar to that involving a tachymeter and graduated rod. Subtense bars were in use in Europe by 1930.

Ref: Wild Heerbrugg, Wild GBL 2m Subtense Bar (Heerbrugg, 1972).

F. Ackerl, "Entfernungsmessungen mit der Wildschen Invar-Basislatte," Zeitschrift für Instrumentenkunde 9 (1932): 393-400.

Further Information:

Range Finder
Wild

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