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An early definition of the metre was one ten-millionth of the Earth quadrant, the distance from the North Pole to the Equator, measured along a meridian through Paris.. The history of the metre starts with the Scientific Revolution that is considered to have begun with Nicolaus Copernicus's publication of De revolutionibus orbium coelestium in 1543.
There are two basic types of cased measuring tapes: spring return tape measures and manual return tape measures. While spring return tape measures are compact and self-retracting, manual return measures are designed for longer distances and often require manual winding, often via hand crank.
The formal definition of calibration by the International Bureau of Weights and Measures (BIPM) is the following: "Operation that, under specified conditions, in a first step, establishes a relation between the quantity values with measurement uncertainties provided by measurement standards and corresponding indications with associated measurement uncertainties (of the calibrated instrument or ...
A coordinate-measuring machine (CMM) is a device that measures the geometry of physical objects by sensing discrete points on the surface of the object with a probe. Various types of probes are used in CMMs, the most common being mechanical and laser sensors, though optical and white light sensors do exist.
Measuring shaft of the nilometer on Roda Island, Cairo. A nilometer is a structure for measuring the Nile River's clarity and water level during the annual flood season in Egypt. [1]
An early surveyor's wheel depicted in the hand of late 18th century British road builder John Metcalf.. The origins of the surveyor's wheel are connected to the origins of the odometer.
North African, 9th century CE, planispheric astrolabe. Khalili Collection. A modern astrolabe made in 2013, in Tabriz, Iran.. An astrolabe (Ancient Greek: ἀστρολάβος astrolábos, ' star-taker '; Arabic: ٱلأَسْطُرلاب al-Asṭurlāb; Persian: ستارهیاب Setāreyāb) is an astronomical instrument dating to ancient times.
Laser scanning is the controlled deflection of laser beams, visible or invisible. [1] Scanned laser beams are used in some 3-D printers, in rapid prototyping, in machines for material processing, in laser engraving machines, in ophthalmological laser systems for the treatment of presbyopia, in confocal microscopy, in laser printers, in laser shows, in Laser TV, and in barcode scanners.