Search results
Results from the WOW.Com Content Network
In manufacturing and mechanical engineering, flatness is an important geometric condition for workpieces and tools. Flatness is the condition of a surface or derived median plane having all elements in one plane. [1] Geometric dimensioning and tolerancing has provided geometrically defined, quantitative ways of defining flatness operationally.
A typical range of surface roughness that can be obtained without resorting to special equipment would fall in the range of 1 to 30 units Ra (average roughness), usually microinches. Surface accuracy or flatness is usually measured in units of helium light band (HLB), one HLB measuring about 280 nm (1.1 × 10 −5 in). Again, without resort to ...
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. It is important to many disciplines and is mostly known for the machining of precision ...
The surface gravity, g, of an astronomical object is the gravitational acceleration experienced at its surface at the equator, including the effects of rotation. The surface gravity may be thought of as the acceleration due to gravity experienced by a hypothetical test particle which is very close to the object's surface and which, in order not to disturb the system, has negligible mass.
Surface force denoted f s is the force that acts across an internal or external surface element in a material body. Normal forces and shear forces between objects are types of surface force. All cohesive forces and contact forces between objects are considered as surface forces.
Gibbs emphasized that for solids, the surface free energy may be completely different from surface stress (what he called surface tension): [13]: 315 the surface free energy is the work required to form the surface, while surface stress is the work required to stretch the surface. In the case of a two-fluid interface, there is no distinction ...
Flatness refers to the shape of a liquid's free surface. On Earth, the flatness of a liquid is a function of the curvature of the planet, and from trigonometry, can be found to deviate from true flatness by approximately 19.6 nanometers over an area of 1 square meter, a deviation which is dominated by the effects of surface tension.
Optical flats in case. About 2.5 centimetres (1 in) in diameter. The third flat from the left is standing on edge, showing the thickness. A λ/20 optical flat that has been coated with aluminum, making a first-surface mirror Two optical flats tested using 589 nm laser-light.