Define standards. State and explain classification of standards.

Define standards. State and explain classification of standards.
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1 Answer

Answer :

Standards:-Standard is a physical representation of a unit of measurement. A known accurate measure of physical quantity is termed as standard. These standards are used to determine the values of other physical quantities by comparison method.

Classifications:-

1) International standards:

International standards are fixed and develop by international agreement.

These standards are maintained at International Bureau of Weights and Measures in

France.

This standard gives different unit having best accuracy.

To preserve best accuracy these standards are periodically check by absolute measurement.

These standards are used to calibrate primary standard only.

These are not available to ordinary user for measurement.

2) Primary standards

These standards are preserved and maintained by National Standard Laboratories which are located at different part of the world.

e.g.-NBS (National Bureau of Standards) located at Washington.

These standards are periodically calibrated by International standards.

3) Secondary standards

These standards are also called as basic standards.

These standards are used by industries and calibration laboratories.

Each industry has its own laboratory.

4) Working standards

These standards are used in general laboratories.

These standards are used to check components and calibrating laboratory instruments to achieve good accuracy and better performance.
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