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Proton Magnetometer
A proton magnetometer, also known as a proton precession magnetometer (PPM), uses the principle of Earth's field nuclear magnetic resonance (EFNMR) to measure very small variations in the Earth's magnetic field, allowing ferrous objects on land and at sea to be detected. It is used in land-based archaeology to map the positions of demolished walls and buildings, and at sea to locate wrecked ships, sometimes for recreational diving. PPMs were once widely used in mineral exploration. They have largely been superseded by Overhauser effect magnetometers and alkali vapour (cesium, rubidium, and potassium) or helium magnetometers, which sample faster and are more sensitive. Principles of operation A direct current flowing in a solenoid creates a strong magnetic field around a hydrogen-rich fluid (kerosine and decane are popular; water can also be used), causing some of the protons to align with that field. The current is then interrupted, and as protons realign themselves with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1967 Proton Magnetometer
Events January * January 1 – Canada begins a year-long celebration of the 100th anniversary of Canadian Confederation, Confederation, featuring the Expo 67 World's Fair. * January 5 ** Spain and Romania sign an agreement in Paris, establishing full consular and commercial relations (not diplomatic ones). ** Charlie Chaplin launches his last film, ''A Countess from Hong Kong'', in the UK. * January 6 – Vietnam War: United States Marine Corps, USMC and Army of the Republic of Vietnam, ARVN troops launch ''Operation Deckhouse Five'' in the Mekong Delta. * January 8 – Vietnam War: Operation Cedar Falls starts. * January 13 – A military coup occurs in Togo under the leadership of Étienne Eyadema. * January 14 – The Human Be-In takes place in Golden Gate Park, San Francisco; the event sets the stage for the Summer of Love. * January 15 ** Louis Leakey announces the discovery of pre-human fossils in Kenya; he names the species ''Proconsul nyanzae, Kenyapithecus africanus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
