Smithsonian - National Museum of American History, Behring Center

 
Physical Sciences Collection - Surveying and Geodesy

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Alidade
Altitude and Azimuth Instrument
Chain, Tape and Base Bar
Compass, Pocket
Compass, Railroad
Compass, Solar
Compass, Surveyor's
Cross, Surveyor's
Electromagnetic Distance Measurement (EDM)
Gradienter
Graphometer
Heliotrope
Holland Circle
Level
Range Finder
Repeating Circle
Theodolite
Transit
Transit and Equal Altitude
Transit, Geodetic
Universal Instrument
Vertical Circle
Waywiser
Zenith Telescope
Miscellaneous

 

Electromagnetic Distance Measurement (EDM)

Astronomers in the 17th century understood that a beam of light could be used to measure the distance from one point to another, but it was the rapid development of electronics during and after World War II that made the practical implantation of this idea possible. The Geodimeter, the first EDM using visible light, was produced in Sweden in 1953. The Tellurometer, the first EDM using microwave radiation, was produced in South Africa in 1954. Infrared EDMs became available in the late 1960s. EDMs were substantially more expensive than chains and tapes, but also substantially more precise, and they quickly displaced these traditional distance measuring instruments.

Ref: Ronald Cox, "Distance-Measurement, Electromagnetic," pp. 177–180 in Robert Bud and Deborah Warner, eds., Instruments of Science (New York and London, 1998).

Collection:

AGA (Geodimeter Model 2)
AGA (Geodimeter Model 4A)
AGA (Geodimeter Model 4B)
AGA (Geodimeter Model 6)
AGA (Geodimeter Model 76)
AGA (Geodimeter Model 8)
Alpha Electronics
Cubic (Cubitape DM-60)
Cubic (Electrotape DM-20)
Hewlett Packard (Model 3800B)
Keuffel & Esser
Laser Systems & Electronics
Laser Systems & Electronics (Ranger)
Precision International (Beetle 500)
Spectra-Physics (Geodolite)
Tellurometer (CA 1000)
Tellurometer (M/RA 1)
Wild (DI-10)
Zeiss (Total Station)