|
Caliper
A caliper (British spelling also calliper, or in plurale tantum sense a pair of calipers) is a device used to measure the dimensions of an object. Many types of calipers permit reading out a measurement on a ruled scale, a dial, or a digital display. Some calipers can be as simple as a compass with inward or outward-facing points, but no scale. The tips of the caliper are adjusted to fit across the points to be measured and the dimension read by measuring between the tips with another measuring tool, such as a ruler. It is used in many fields such as mechanical engineering, metalworking, forestry, woodworking, science and medicine. Plural vs. singular A single tool might be referred to as a "caliper" or as "calipers", like a pair of scissors or glasses (a "plural only" or ''plurale tantum'' form). In colloquial usage, the phrase "pair of verniers" or just " vernier" might refer to a vernier caliper. Colloquially these phrases can also refer to dial calipers, although they in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caliper Detail View
A caliper (British spelling also calliper, or in plurale tantum sense a pair of calipers) is a device used to measure the dimensions of an object. Many types of calipers permit reading out a measurement on a ruled scale, a dial, or a digital display. Some calipers can be as simple as a compass with inward or outward-facing points, but no scale. The tips of the caliper are adjusted to fit across the points to be measured and the dimension read by measuring between the tips with another measuring tool, such as a ruler. It is used in many fields such as mechanical engineering, metalworking, forestry, woodworking, science and medicine. Plural vs. singular A single tool might be referred to as a "caliper" or as "calipers", like a pair of scissors or glasses (a "plural only" or ''plurale tantum'' form). In colloquial usage, the phrase "pair of verniers" or just " vernier" might refer to a vernier caliper. Colloquially these phrases can also refer to dial calipers, although they in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vernier Scale
A vernier scale, named after Pierre Vernier, is a visual aid to take an accurate measurement reading between two graduation markings on a linear scale by using mechanical interpolation, thereby increasing resolution and reducing measurement uncertainty by using vernier acuity to reduce human estimation error. It may be found on many types of instrument measuring linear or angular quantities, but in particular on a vernier caliper which measures internal or external diameter of hollow cylinders. The vernier is a subsidiary scale replacing a single measured-value pointer, and has for instance ten divisions equal in distance to nine divisions on the main scale. The interpolated reading is obtained by observing which of the vernier scale graduations is coincident with a graduation on the main scale, which is easier to perceive than visual estimation between two points. Such an arrangement can go to a higher resolution by using a higher scale ratio, known as the vernier constant. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Micrometer (device)
A micrometer, sometimes known as a micrometer screw gauge, is a device incorporating a calibrated screw widely used for accurate measurement of components in mechanical engineering and machining as well as most mechanical trades, along with other metrological instruments such as dial, vernier, and digital calipers. Micrometers are usually, but not always, in the form of calipers (opposing ends joined by a frame). The spindle is a very accurately machined screw and the object to be measured is placed between the spindle and the anvil. The spindle is moved by turning the ratchet knob or thimble until the object to be measured is lightly touched by both the spindle and the anvil. Micrometers are also used in telescopes or microscopes to measure the apparent diameter of celestial bodies or microscopic objects. The micrometer used with a telescope was invented about 1638 by William Gascoigne, an English astronomer. History The word ''micrometer'' is a neoclassical coinage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pierre Vernier
Pierre Vernier (19 August 1580 at Ornans, Franche-Comté (at that time ruled by the Spanish Habsburgs, now part of France) – 14 September 1637, same location) was a French mathematician and instrument-inventor. He was the inventor and eponym of the vernier scale used in measuring devices. Life He was born in Ornans, France, in 1580. He was taught science by his father. He became captain and castellan of the castle at Ornans, for the King of Spain. He was also later councillor and director general of economy in the County of Burgundy. In Brussels, in the year 1631, Vernier published his treatise ''La construction, l'usage, et les propriétés du quadrant nouveau de mathématique'', and dedicated it to the Infanta. In it, he described the ingenious device which now bears his name, the vernier scale. To a quadrant with a primary scale in half degrees Vernier proposed to attach a movable sector, thirty-one half degrees in length but divided into thirty equal parts (each pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metalworking
Metalworking is the process of shaping and reshaping metals to create useful objects, parts, assemblies, and large scale structures. As a term it covers a wide and diverse range of processes, skills, and tools for producing objects on every scale: from huge ships, buildings, and bridges down to precise engine parts and delicate jewelry. The historical roots of metalworking predate recorded history; its use spans cultures, civilizations and millennia. It has evolved from shaping soft, native metals like gold with simple hand tools, through the smelting of ores and hot forging of harder metals like iron, up to highly technical modern processes such as machining and welding. It has been used as an industry, a driver of trade, individual hobbies, and in the creation of art; it can be regarded as both a science and a craft. Modern metalworking processes, though diverse and specialized, can be categorized into one of three broad areas known as forming, cutting, or joining processes. Mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Compass (drafting)
A compass, more accurately known as a pair of compasses, is a technical drawing instrument that can be used for inscribing circles or arcs. As dividers, it can also be used as a tool to mark out distances, in particular, on maps. Compasses can be used for mathematics, drafting, navigation and other purposes. Prior to computerization, compasses and other tools for manual drafting were often packaged as a set with interchangeable parts. By the mid-twentieth century, circle templates supplemented the use of compasses. Today those facilities are more often provided by computer-aided design programs, so the physical tools serve mainly a didactic purpose in teaching geometry, technical drawing, etc. Construction and parts Compasses are usually made of metal or plastic, and consist of two "legs" connected by a hinge which can be adjusted to allow changing of the radius of the circle drawn. Typically one leg has a spike at its end for anchoring, and the other leg holds a drawing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American And British English Spelling Differences
Despite the various List of dialects of English, English dialects spoken from country to country and within different regions of the same country, there are only slight regional variations in English orthography, the two most notable variations being British and American spelling. Many of Comparison of American and British English, the differences between American English, American and British English date back to a time before spelling standards were developed. For instance, some spellings seen as "American" today were once commonly used in Britain, and some spellings seen as "British" were once commonly used in the United States. A "British standard" began to emerge following the 1755 publication of Samuel Johnson's ''A Dictionary of the English Language'', and an "American standard" started following the work of Noah Webster and, in particular, his ''Webster's Dictionary, An American Dictionary of the English Language'', first published in 1828. Webster's efforts at spellin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marking Out
Marking out or layout means the process of transferring a design or pattern to a workpiece, as the first step in the manufacturing process. It is performed in many industries or hobbies although in the repetition industries the machine's initial setup is designed to remove the need to mark out every individual piece. Manufacturing Marking out consists of transferring the dimensions from the plan to the workpiece in preparation for the next step, machining or manufacture. Typical tools include: * Surface plate or ''marking out table'' — provides a true surface from which to work * Angle plates — assist in holding the workpiece perpendicular to the table * Scriber — is the equivalent of a pen or pencil. It literally scratches the metal surface leaving behind a fine, bright line * Height gauge or ''scribing block'' — allows lines to be scribed at a preset distance, from the tables surface * Surface gauge — an ungraduated comparison measuring tool that pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forestry
Forestry is the science and craft of creating, managing, planting, using, conserving and repairing forests, woodlands, and associated resources for human and environmental benefits. Forestry is practiced in plantations and natural stands. The science of forestry has elements that belong to the biological, physical, social, political and managerial sciences. Forest management play essential role of creation and modification of habitats and affect ecosystem services provisioning. Modern forestry generally embraces a broad range of concerns, in what is known as multiple-use management, including: the provision of timber, fuel wood, wildlife habitat, natural water quality management, recreation, landscape and community protection, employment, aesthetically appealing landscapes, biodiversity management, watershed management, erosion control, and preserving forests as " sinks" for atmospheric carbon dioxide. Forest ecosystems have come to be seen as the most important componen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chinese Era Name
Chinese era names were titles used by various Chinese dynasties and regimes in Imperial China for the purpose of year identification and numbering. The first monarch to adopt era names was the Emperor Wu of Han in 140 BCE, and this system remained the official method of year identification and numbering until the establishment of the Republic of China in 1912 CE, when the era name system was superseded by the Republic of China calendar. Other polities in the Sinosphere—Korea, Vietnam and Japan—also adopted the concept of era name as a result of Chinese politico-cultural influence. Description Chinese era names were titles adopted for the purpose of identifying and numbering years in Imperial China. Era names originated as mottos or slogans chosen by the reigning monarch and usually reflected the political, economic and/or social landscapes at the time. For instance, the first era name proclaimed by the Emperor Wu of Han, ''Jianyuan'' (; lit. "establishing the origin"), was r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
