prototype meterの例文

• In 1908, two teams of researchers, one led by Michelson, defined the length of the international prototype meter in terms of light waves.
• Because the definition of the meter is now based on a light wavelength, the international prototype meter is not quite as indispensable as it once was.
• In contrast, the reference standard for the meter is no longer defined by a physical object ( as the former international prototype meter ( IPM ) or originally the " m鑤re des Archives " ).
• This agreement replaced the 1889 international prototype meter located in Paris, which was a metal bar made of a platinum-iridium alloy ( one of a series of standard meter bars, originally constructed to be one ten-millionth of a quadrant of the Earth's polar circumference ).
• At the same time, the International Prototype Meter was used as standard for the length of a meter until 1960, when at the General Conference on Weights and Measures the meter was defined in terms of the orange-red emission line in the electromagnetic spectrum of the krypton-86 atom in vacuum.