Helmholtz Coil
name: label: maker
content: Schonstedt Instrument Company
notes: label: Description
content: This Helmholtz coil is part of a Vector Airborne Magnetometer. For other pieces of this instrument, see records 1981.0687.01-.13.
label: Description
content: A Vector Airborne Magnetometer measures the three components of the earth's magnetic field, but orients them so as to null out two of them, thus putting the third component in the direction of the magnetic field. This type of instrument served for 25 years as the heart of Project MAGNET, an airborne magnetic survey of ocean areas that began operation in April 1953 under the command of the Naval Hydrographic Office. Project MAGNET continues to this day, though with other sorts of detectors. This example is marked "U.S. NAVY HYDROGRAPHIC OFFICE VAM-2A3." The Naval Oceanographic Office transferred it to the Smithsonian in 1979.
label: Description
content: <p>Eric Schonstedt and Henry Irons developed the design while working at the Naval Ordnance Laboratory. It is a refinement of the Magnetic Airborne Detector that the Naval Ordnance Laboratory and Bell Telephone Laboratories developed during World War II, in order to locate submerged submarines.</p>
label: Description
content: <p>Ref: E. O. Schonstedt and H. R. Irons, "Airborne Magnetometer for Measuring the Earth's Magnetic Vector,"<i>Science</i> 110 (1949): 377-378; E. O. Schonstedt and H. R. Irons, "Airborne Magnetometer for Determining All Magnetic Components,<i>" Transactions of the American Geophysical Union</i> 34 (1953): 363-378; E. O. Schonstedt and H. R. Irons, "NOL Vector Airborne Magnetometer Type 2A," <i>Transactions of the American Geophysical Union</i> 36 (1955): 25-41; <i>Magnetic Airborne Detector Programs. Summary Technical Report. Division 6, National Research and Development Committee</i>, vol. 6 (1946); William Anspacher, et. al., <i>The Legacy of the White Oak Laboratory</i> (Dahlgren, Va., 2000), chapter 10.</p>
place: label: place made
content: United States: Maryland, Silver Spring
setName: label: See more items in
content: Medicine and Science: Physical Sciences
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1981.0687.04
label: catalog number
content: 1981.0687.04
label: accession number
content: 1981.0687
objectType: label: Object Name
content: helmholtz coil, vector airborne magnetometer
physicalDescription: label: Measurements
content: overall: 60 cm x 60 cm x 58.5 cm; 23 5/8 in x 23 5/8 in x 23 1/32 in