Search results
Results From The WOW.Com Content Network
A tachometer that can indicate up to 7000 RPM (left) A tachometer (revolution-counter, tach, rev-counter, RPM gauge) is an instrument measuring the rotation speed of a shaft or disk, as in a motor or other machine. [1] The device usually displays the revolutions per minute (RPM) on a calibrated analogue dial, but digital displays are ...
Another device used in tacheometry to measure distance between the measuring station and a desired point is the subtense bar. [2] This is a rigid rod, usually of a material insensitive to change in temperature such as invar, of fixed length (typically 2 metres (6.6 ft)). The subtense bar is mounted on a tripod over the station to which the ...
Gradiometer any device that measures spatial variations of a physical quantity. For example, as done in gravity gradiometry. Parking meter measures time a vehicle is parked at a particular spot, usually with a fee. Postage meter measures postage used from a prepaid account. S meter measures the signal strength processed by a communications ...
In metrology (the science of measurement), a standard (or etalon) is an object, system, or experiment that bears a defined relationship to a unit of measurement of a physical quantity. [1] Standards are the fundamental reference for a system of weights and measures , against which all other measuring devices are compared.
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". [15] It establishes a common understanding of units, crucial to human activity. [2]
heat capacity: joule per kelvin (J⋅K −1) constant of integration: varied depending on context speed of light (in vacuum) 299,792,458 meters per second (m/s) speed of sound: meter per second (m/s) specific heat capacity: joule per kilogram per kelvin (J⋅kg −1 ⋅K −1) viscous damping coefficient kilogram per second (kg/s)
A unit of measurement, or unit of measure, is a definite magnitude of a quantity, defined and adopted by convention or by law, that is used as a standard for measurement of the same kind of quantity. [1] Any other quantity of that kind can be expressed as a multiple of the unit of measurement. [2] For example, a length is a physical quantity.
It is the only system of measurement with official status in nearly every country in the world, employed in science, technology, industry, and everyday commerce. The SI system is coordinated by the International Bureau of Weights and Measures which is abbreviated BIPM from French: Bureau international des poids et mesures.