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It spans a wide range of manufacturing procedures and optical test configurations. The manufacture of a conventional spherical lens typically begins with the generation of the optic's rough shape by grinding a glass blank. [1] This can be done, for example, with ring tools. Next, the lens surface is polished to its final form.
Optical lens design is the process of designing a lens to meet a set of performance requirements and constraints, including cost and manufacturing limitations. Parameters include surface profile types (spherical, aspheric, holographic, diffractive, etc.), as well as radius of curvature, distance to the next surface, material type and optionally tilt and decenter.
Surface metrology is the measurement of small-scale features on surfaces, and is a branch of metrology.Surface primary form, surface fractality, and surface finish (including surface roughness) are the parameters most commonly associated with the field.
A 1951 USAF resolution test chart is a microscopic optical resolution test device originally defined by the U.S. Air Force MIL-STD-150A standard of 1951. The design provides numerous small target shapes exhibiting a stepped assortment of precise spatial frequency specimens.
Equipment rental was first developed in Anglo-Saxon countries. It emerged in the UK after the First World War and has now become a multi-billion euro business providing a wide range of construction and industrial equipment for customers globally.The American Rental Association was founded as early as 1955, [1] and the first waves of consolidation took place in the 1970s in North America ...
Some rental businesses give "free days" on rental contract billing processes, for example on a national or public holiday, and therefore the equipment does not earn any money on those days, even though it is physically on rent. Some companies charge minimum rates, for example you may rent an excavator for 1 day, but be charged a three-day minimum.
In the UK Crane Rental industry in the UK, which is one of the most highly developed crane rental industries in the world, special regulations for health and safety and rental procedures are in place. These are maintained as the CPA regulations. [1] In Europe, European Rental Association is the trade body representing the equipment rental industry.
Optical glass refers to a quality of glass suitable for the manufacture of optical systems such as optical lenses, prisms or mirrors.Unlike window glass or crystal, whose formula is adapted to the desired aesthetic effect, optical glass contains additives designed to modify certain optical or mechanical properties of the glass: refractive index, dispersion, transmittance, thermal expansion and ...