Metrology - Standards

Standards

See also: Standard (metrology)

Standards are objects or ideas that are designated as being authoritative for some accepted reason. Whatever value they possess is useful for comparison to unknowns for the purpose of establishing or confirming an assigned value based on the standard. The design of this comparison process for measurements is metrology. The execution of measurement comparisons for the purpose of establishing the relationship between a standard and some other measuring device is calibration.

The ideal standard is independently reproducible without uncertainty. This is what the creators of the “meter” length standard were attempting to do in the 19th century when they defined a meter as one ten-millionth of the distance from the equator to one of the Earth’s poles. Later, it was learned that the Earth’s surface is an unreliable basis for a standard. The Earth is not spherical and it is constantly changing in shape. But the special alloy meter bars that were created and accepted in that time period standardized international length measurement until the 1950s. Careful calibrations allowed tolerances as small as 10 parts per million to be distributed and reproduced in metrology laboratories worldwide, regardless of whether the rest of the metric system was implemented and in spite of the shortfalls of the meter’s original basis.

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Famous quotes containing the word standards:

    With his brows knit, his mind made up, his will resolved and resistless, he advances, crashing his way through the host of weak, half-formed, dilettante opinions, honest and dishonest ways of thinking, with their standards raised, sentimentalities and conjectures, and tramples them all into dust. See how he prevails; you don’t even hear the groans of the wounded and dying.
    Henry David Thoreau (1817–1862)

    Today so much rebellion is aimless and demoralizing precisely because children have no values to challenge. Teenage rebellion is a testing process in which young people try out various values in order to make them their own. But during those years of trial, error, embarrassment, a child needs family standards to fall back on, reliable habits of thought and feeling that provide security and protection.
    Neil Kurshan (20th century)

    Chief among our gains must be reckoned this possibility of choice, the recognition of many possible ways of life, where other civilizations have recognized only one. Where other civilizations give a satisfactory outlet to only one temperamental type, be he mystic or soldier, business man or artist, a civilization in which there are many standards offers a possibility of satisfactory adjustment to individuals of many different temperamental types, of diverse gifts and varying interests.
    Margaret Mead (1901–1978)