|
Tribrach (instrument)
A tribrach with an optical plummet (the black cylinder pointing to the left lower corner of the image). A tribrach is an attachment plate used to attach a surveying instrument, for example a theodolite, total station, GNSS antenna or target to a tripod. A tribrach allows the survey instrument to be repeatedly placed in the same position over a surveying marker point with sub-millimetre precision, by loosening and re-tightening a lock to adjust the instrument base in a horizontal plane. Components of a tribrach The device consists of two triangular metal plates connected at their corners by leveling thumbscrews, a bubble level, a locking mechanism and often an optical plummet. The centre of the bottom plate of the tribrach has a 5/8-11 UNC thread bolt hole which is used to attach the tribrach to the tripod. The top plate has three small holes or slots spaced 120˚ apart above leveling thumbscrews, and a locking mechanism which enables a survey instrument or target to be accu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tribrach For Surveying Instruments , a device used in surveying for mounting an instrument on a surveyor's tripod.
{{Disambig ...
Tribrach can refer to: *Tribrach (poetry), a metrical foot of three short syllables. *Tribrach (instrument) A tribrach with an optical plummet (the black cylinder pointing to the left lower corner of the image). A tribrach is an attachment plate used to attach a surveying instrument, for example a theodolite, total station, GNSS antenna or target to a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thumbscrew (fastener)
At a minimum, a screw drive is a set of shaped cavities and protrusions on the screw head that allows torque to be applied to it. Usually, it also involves a mating tool, such as a screwdriver, that is used to turn it. The following heads are categorized based on frequency, with some of the less-common drives being classified as "tamper-resistant." Most heads come in a range of sizes, typically distinguished by a number, such as "Phillips #00". These sizes do not necessarily describe a particular dimension of the drive shape, but rather are arbitrary designations. Slotted drives Slot Slot screw drives have a single horizontal indentation (the ''slot'') in the fastener head and is driven by a "common blade" or flat-bladed screwdriver. This form was the first type of screw drive to be developed, and for centuries, it was the simplest and cheapest to make. Additionally, it is unique compared to other common drives, due to it being straightforward to manufacture the slot h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asphalt
Asphalt, also known as bitumen (, ), is a sticky, black, highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term asphaltum was also used. Full text at Internet Archive (archive.org) The word is derived from the Ancient Greek ἄσφαλτος ''ásphaltos''. The largest natural deposit of asphalt in the world, estimated to contain 10 million tons, is the Pitch Lake located in La Brea in southwest Trinidad (Antilles island located on the northeastern coast of Venezuela), within the Siparia Regional Corporation. The primary use (70%) of asphalt is in Road surface, road construction, where it is used as the glue or binder mixed with construction aggregate, aggregate particles to create asphalt concrete. Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roofs. In material sciences an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reflector On Tribranch
Reflector may refer to: Science * Reflector, a device that causes reflection (for example, a mirror or a retroreflector) * Reflector (photography), used to control lighting contrast * Reflecting telescope * Reflector (antenna), the part of an antenna that reflects radio waves * Reflector (cipher machine), a component of some rotor machines in cryptography *Reflector (microsatellite), space debris research microsatellite * ''Reflector'', the newsletter of the Boston section of the Institute of Electrical and Electronics Engineers * Reflector, in math, the left adjoint in a reflective subcategory * Neutron reflector, in physics Computing * .NET Reflector, code browser utility * Reflector, in an electronic mailing list, a single email address that reflects (sends/remails) a copy of an email sent to it to other email addresses * Reflector router, used in a distributed reflected denial of service attack (DRDoS) * Reflector (cellular automaton), a type of pattern * Reflector, conferenci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The first laser was built in 1960 by Theodore H. Maiman at Hughes Research Laboratories, based on theoretical work by Charles Hard Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light which is ''coherent''. Spatial coherence allows a laser to be focused to a tight spot, enabling applications such as laser cutting and lithography. Spatial coherence also allows a laser beam to stay narrow over great distances (collimation), enabling applications such as laser pointers and lidar (light detection and ranging). Lasers can also have high temporal coherence, which allows them to emit light with a very narrow spectrum. Alternatively, temporal coherence can be used to produce ultrashort pulses of ligh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cross-hair
A reticle, or reticule also known as a graticule, is a pattern of fine lines or markings built into the eyepiece of an optical device such as a telescopic sight, spotting scope, theodolite, optical microscope or the screen of an oscilloscope, to provide measurement references during visual inspections. Today, engraved lines or embedded fibers may be replaced by a digital image superimposed on a screen or eyepiece. Both terms may be used to describe any set of patterns used for aiding visual measurements and calibrations, but in modern use ''reticle'' is most commonly used for weapon sights, while ''graticule'' is more widely used for non-weapon measuring instruments such as oscilloscope display, astronomic telescopes, microscopes and slides, surveying instruments and other similar devices. There are many variations of reticle pattern; this article concerns itself mainly with the most rudimentary reticle: the crosshair. Crosshairs are typically represented as a pair of perpe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plumb Bob
A plumb bob, plumb bob level, or plummet, is a weight, usually with a pointed tip on the bottom, suspended from a string and used as a vertical reference line, or plumb-line. It is a precursor to the spirit level and used to establish a vertical datum. It is typically made of stone, wood, or lead, but can also be made of other metals. If it is used for decoration, it may be made of bone or ivory. The instrument has been used since at least the time of ancient EgyptDenys A. Stocks. Experiments in Egyptian archaeology: stoneworking technology in ncient Egypt'. Routledge; 2003. . p. 180. to ensure that constructions are "plumb", or vertical. It is also used in surveying, to establish the nadir with respect to gravity of a point in space. It is used with a variety of instruments (including levels, theodolites, and steel tapes) to set the instrument exactly over a fixed survey marker or to transcribe positions onto the ground for placing a marker. Etymology The ''plu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optics
Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultraviolet, and infrared light. Because light is an electromagnetic wave, other forms of electromagnetic radiation such as X-rays, microwaves, and radio waves exhibit similar properties. Most optical phenomena can be accounted for by using the classical electromagnetic description of light. Complete electromagnetic descriptions of light are, however, often difficult to apply in practice. Practical optics is usually done using simplified models. The most common of these, geometric optics, treats light as a collection of rays that travel in straight lines and bend when they pass through or reflect from surfaces. Physical optics is a more comprehensive model of light, which includes wave effects such as diffraction and interference that cannot be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanism (engineering)
In engineering, a mechanism is a Machine, device that transforms input forces and movement into a desired set of output forces and movement. Mechanisms generally consist of moving components which may include: * Gears and gear trains; * belt drive, Belts and chain drives; * Cams and cam follower, followers; * Linkage (mechanical), Linkages; * Friction devices, such as brakes or clutches; * Structural components such as a frame, fasteners, bearings, springs, or lubricants; * Various machine elements, such as splines, pins, or keys. The German scientist Franz Reuleaux defines ''machine'' as "a combination of resistant bodies so arranged that by their means the mechanical forces of nature can be compelled to do work accompanied by certain determinate motion". In this context, his use of ''machine'' is generally interpreted to mean ''mechanism''. The combination of force and movement defines Power (physics), power, and a mechanism manages power to achieve a desired set of forces and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bubble Level
A spirit level, bubble level, or simply a level, is an instrument designed to indicate whether a surface is horizontal (level) or vertical (plumb). Different types of spirit levels may be used by carpenters, stonemasons, bricklayers, other building trades workers, surveyors, millwrights and other metalworkers, and in some photographic or videographic work. Construction Early tubular spirit levels had very slightly curved glass vials with constant inner diameter at each viewing point. These vials are incompletely filled with a liquid, usually a colored spirit or alcohol, leaving a bubble in the tube. They have a slight upward curve, so that the bubble naturally rests in the center, the highest point. At slight inclinations the bubble travels away from the marked center position. Where a spirit level must also be usable upside-down or on its side, the curved constant-diameter tube is replaced by an uncurved barrel-shaped tube with a slightly larger diameter in its midd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surveyors Tripod Head
Surveying or land surveying is the technique, profession, art, and science of determining the terrestrial two-dimensional or three-dimensional positions of points and the distances and angles between them. A land surveying professional is called a land surveyor. These points are usually on the surface of the Earth, and they are often used to establish maps and boundaries for ownership, locations, such as the designed positions of structural components for construction or the surface location of subsurface features, or other purposes required by government or civil law, such as property sales. Surveyors work with elements of geodesy, geometry, trigonometry, regression analysis, physics, engineering, metrology, programming languages, and the law. They use equipment, such as total stations, robotic total stations, theodolites, GNSS receivers, retroreflectors, 3D scanners, LiDAR sensors, radios, inclinometer, handheld tablets, optical and digital levels, subsurface locators, dron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Tribrach (instrument)")
_crop.jpg "Click for more on -> Surveyors Tripod Head")