Measuring Instruments

Measuring instrument is a device for determining the value of some quantity in terms of a standard unit. In the physical sciences, quality assurance, and engineering, measurement is the activity of obtaining and comparing physical quantities of real-world objects and events. Measuring instruments, and formal test methods which define the instrument's use, are the means by which these relations of numbers are obtained. All measuring instruments are subject to varying degrees of instrument error and measurement uncertainty.

Scientists, engineers and other humans use a vast range of instruments to perform their measurements. These instruments may range from simple objects such as rulers and stopwatches to electron microscopes and particle accelerators. Virtual instrumentation is widely used in the development of modern measuring instruments. A wide variety of measuring instruments is used for different purposes, for example:

•Scale – for measuring weight,

•Altimeter – for measuring altitude,

•Bolometer; Radiometer – for measuring radiant energy,

•Thermometer; Calorimetry – for measuring heat,

•Interferometer; Photometry – for measuring light,

•Clocks and Watches; Sundial; Clepsydra – for measuring time, and others.

METROLOGY is the science of measurement. Metrology includes all theoretical and practical aspects of measurement. Metrology is defined by the International Bureau of Weights and Measures (BIPM) as "the science of measurement, embracing both experimental and theoretical determinations at any level of uncertainty in any field of science and technology." Metrology is a very broad field and may be divided into three subfields:

Subfield	Definition
Scientific or fundamental metrology	concerns the establishment of quantity systems, unit systems, units of measurement, the development of new measurement methods, realisation of measurement standards and the transfer of traceability from these standards to users in society.
Applied or industrial metrology	concerns the application of measurement science to manufacturing and other processes and their use in society, ensuring the suitability of measurement instruments, their calibration and quality control of measurements.
Legal metrology	concerns regulatory requirements of measurements and measuring instruments for the protection of health, public safety, the environment, enabling taxation, protection of consumers and fair trade.

Дата добавления: 2015-10-21