WHAT IS THE STANDARD METER? MAIN FEATURES - CULTURE VOCABULARY - 2025

The standard meter is a specially constructed measuring rod that was used as the standard for the construction of all other length measurements in the metric system.

The first standard meter was deposited in the archives of Paris in 1796. Today, it is housed in the Conservatory of Arts and Crafts in this French city.

Now the copy of this is known as the International Metro Prototype. By 1889 physical metallurgy and the design of measuring devices had improved significantly.

In particular, an artifact produced from the platinum-iridium alloy was rigorously tested and duly selected to replace its precursor. This remained the international measurement standard until 1960.

History

Background

Most historians agree that Gabriel Mouton was the father of the metric system. Mouton proposed a decimal system of measurement in 1670.

This vicar of the Church of Saint Paul in Lyon, France, based the system on the length of an arc minute of a great circle of the Earth.

This measurement is now called the nautical mile. He also proposed as the unit of length the oscillation of a pendulum with a frequency of one beat per second (about 25 cm).

However, these proposals faced endless arbitrary systems of weights and measures in force in France and the rest of Europe.

These were measurements used since medieval times, and ranged from the size of barley grains to the length of human feet.

The debate lasted for more than a century, until economic and scientific progress made it necessary to demand more rational measures.

The role of the French National Constituent Assembly

In 1790 the French National Assembly debated the desirability of a uniform system of weights and measures. This system would be applied in France and internationally.

So it had to be based on some unchanging unity of nature. Furthermore, it had to be easily reproduced and measured with a high degree of precision.

Thus, a commission of the French Academy of Sciences created a simple and scientific system. The unit of length had to be a portion of the circumference of the Earth.

And the measures of capacity (volume) and mass had to be derived from the unit of length. In this way the basic units of the system were related to each other and to nature.

In addition, it was determined that the standard meter should be constructed to equal one ten thousandth of the distance from the North Pole to the equator, along the working meridian.

This point was located near Dunkerque in France, and Barcelona in Spain. This would be the physical standard that the meter would represent.

The construction of the standard metro

The measurement team was led by Pierre-Francois-André Méchain and Jean-Baptiste-Joseph Delambre. The measurement took a total of six years.

So the meter was meant to equal 10-7 or one ten thousandth of the length of the meridian through Paris, from the pole to the equator.

However, the first prototype was missing 0.2 millimeters because the researchers miscalculated the flattening of the Earth due to its rotation. Still, this length became the standard.

References

1. Smith, GT (2016). Machine Tool Metrology: An Industrial Handbook. Hampshire: Springer.
2. Bureau International de Poids et Mesures. (s / f). The former Prototype Meter. Retrieved on November 28, 2017, from bipm.org
3. US Metric Association (s / f). Origin of the Metric System. Retrieved on November 28, 2017, from us-metric.org
4. Cochrane, RC (1966). Measures for Progress: A History of the National Bureau of Standards, Issue 275. National Bureau of Standards, US Department of Commerce.
5. US National Institute of Standards and Technology. (s / f). Historical context of the SI. Retrieved on November 28, 2017, from nist.gov