Search results
Results from the WOW.Com Content Network
6) defines the beam diameter as the distance between diametrically opposed points in that cross-section of a beam where the power per unit area is 1/e (0.368) times that of the peak power per unit area. This is the beam diameter definition that is used for computing the maximum permissible exposure to a laser beam.
Example of true position geometric control defined by basic dimensions and datum features. Geometric dimensioning and tolerancing (GD&T) is a system for defining and communicating engineering tolerances via a symbolic language on engineering drawings and computer-generated 3D models that describes a physical object's nominal geometry and the permissible variation thereof.
The beam width is the single most important characteristic of a laser beam profile. At least five definitions of beam width are in common use: D4σ, 10/90 or 20/80 knife-edge, 1/e 2, FWHM, and D86. The D4σ beam width is the ISO standard definition and the measurement of the M 2 beam quality parameter requires the measurement of the D4σ widths.
Means that a feature of size is at the limit of its size tolerance in the direction that leaves the least material on the part. Thus an internal feature of size (e.g., a hole) at its biggest diameter, or an external feature of size (e.g., a flange) at its smallest thickness. The GD&T symbol for LMC is a circled L.
In civil engineering, clearance refers to the difference between the loading gauge and the structure gauge in the case of railroad cars or trams, or the difference between the size of any vehicle and the width/height of doors, the width/height of an overpass or the diameter of a tunnel as well as the air draft under a bridge, the width of a ...
Geometrical Product Specification and Verification (GPS&V) [1] is a set of ISO standards developed by ISO Technical Committee 213. [2] The aim of those standards is to develop a common language to specify macro geometry (size, form, orientation, location) and micro-geometry (surface texture) of products or parts of products so that the language can be used consistently worldwide.
ISO 11146-1:2005 Part 1: Stigmatic and simple astigmatic beams; ISO 11146-2:2005 Part 2: General astigmatic beams; ISO/TR 11146-3:2004 Part 3: Intrinsic and geometrical laser beam classification, propagation and details of test methods; ISO 11151 Lasers and laser-related equipment – Standard optical components
When measuring the beam parameter product and M 2, one uses the D4σ or "second moment" width of the beam to determine both the radius of the beam's waist and the divergence in the far field. [ 2 ] The BPP can be easily measured by placing an array detector or scanning-slit profiler at multiple positions within the beam after focusing it with a ...