Metrology is the scientific study of weights and measures. Environmental metrology is the science of using instruments to measure the world around us all. After listening to the presentation, you may continue to click on the remaining slides.
12. The meter has its origin in August of 1793 when the Republican Government of France decreed the unit of the length to be 10- 7 of the Earth’s quadrant passing through Paris and that the unit be called the meter.
13. Five years later, the survey of the arc was completed and three platinum standards and several iron copies of the meter were made. Subsequent examination showed the length of the Earth’s quadrant had been wrongly surveyed , instead of altering the length of the meter to maintain the 10- 7 ratio, the meter was redefined as the distance between the two marks on a bar.
14. A practical scale for time for world-wide use has two essential elements: a realization of the unit of time and a continuous temporal reference. The reference used is International Atomic Time (TAI).
15. A time scale calculated at the BIPM using data from some two hundred atomic clocks in over fifty national laboratories. The Louis Essen caesium clock developed in 1938. (top) First Atomic Clock in 1949 (middle) Modern Atomic Clocks (bottom)
20. IFREMER Laboratory for Deep Environment. Devices of observation, samples and measurements (autonomous and on cable) controlled by acoustical navigation.