// JavaScript Document

var quotes = new Array;

quotes.push("<div><p><strong>Afocal</strong><br /> An optical system with object and image points at infinity. Literally, without focal length.</p></div>");
quotes.push("<div><p><strong>Ambient Light </strong><br /> Light present in the environment around a detecting or interpreting device, especially a machine vision system, and generated from outside sources.  Such light must be treated as noise by the system.</p></div>");


quotes.push("<div><p><strong>Anode</strong><br /> The part of an electrical circuit in which the electrons leave (a cathode-ray tube) or enter (an electrolytic cell) a unit in the circuit.</p></div>");


quotes.push("<div><p><strong>Arc Discharge </strong><br /> The electric arc that is a particular discharge between two electrodes in a gas or vapor which is characterized by high cathode densities and a low voltage drop.</p></div>");


quotes.push("<div><p><strong>Arc Spectrum</strong><br /> The spectrum of the light produced by vaporizing an element in an electrical arc.</p></div>");


quotes.push("<div><p><strong>Aperture Stop</strong><br /> A physical constraint, often a lens retainer, that limits the diameter of the axial light bundle allowed to pass through a lens.</p></div>");

quotes.push("<div><p><strong>Convex</strong><br /> Denoting a spherically shaped surface; curved outward.</p></div>");

quotes.push("<div><p><strong>Convergence</strong><br /> In optics, the bending of light rays toward each other, as by a convex or positive lens.</p></div>");


quotes.push("<div><p><strong>Core</strong><br /> The light conducting portion of an optical fibe, defined by the region of high refractive index.</p></div>");

quotes.push("<div><p><strong>Collimated light</strong><br /> Light in which every ray from any given object point can be considered to be parallel to every other. This is never completely the case, even light from a star is really diverging and all collimators have aberrations.</p></div>");

quotes.push("<div><p><strong>Depth of Field </strong><br /> The distance through which satisfactory definition can be obtained when the lens is in focus or a particular distance. </p></div>");

quotes.push("<div><p><strong>Depth of Focus </strong><br /> The range of image distances that corresponds to the range of object distances covered by the depth of field.</p></div>");

quotes.push("<div><p><strong>Diode</strong><br /> A two electrode device with an anode and a cathode that passes current in only one direction.  It may be designed as an electron tube or as a semiconductor device.</p></div>");

quotes.push("<div><p><strong>Electro-optics </strong><br /> The science and technology concerned with use of applied electrical fields to generate and control optical radiation.  The term electro-optic (E-O) often is used erroneously as a synonym for optoelectronic.</p></div>");

quotes.push("<div><p><strong>Ellipsoidal Reflector </strong><br /> A concave reflector that has the form of an ellipsoid of revolution. All light rays emitted from one focal point of the ellipsoid will pass through the second foci of the ellipsoid.</p></div>");

quotes.push("<div><p><strong>Filter</strong><br /> A device used to attenuate particular wavelengths or frequencies while passing others with relatively no change.</p></div>");

quotes.push("<div><p><strong>Fixed Focused </strong><br /> Describes devices that are not provided with a means of focusing.</p></div>");

quotes.push("<div><p><strong>Flicker</strong><br /> The fluctuation in apparent illumination that has a rate comparable to the reciprocal of the period of persistence in vision.</p></div>");

quotes.push("<div><p><strong>Focal Length </strong><br /> The effective focal length (EFL) is the distance from the principal point to the focal point.  The back focal length (BFL) is the distance from the vertex of the last lens to the second focal point. The front focal length (FFL) is the distance from the first lens surface to the first focal point.</p></div>");

quotes.push("<div><p><strong>Focal Point </strong><br /> The point on the optical axis of a lens, to which and incident bundle of parallel light rays will converge.</p></div>");

quotes.push("<div><p><strong>Foot Candle </strong><br /> (fc) unit of illuminance equal to one lumen square foot.</p></div>");

quotes.push("<div><p><strong>Getter</strong><br />In vacuum deposition, a device that removes contaminants from the vacuum chamber.</p></div>");

quotes.push("<div><p><strong>Halogen</strong><br /> Any of the five elements: astatine, chlorine, fluorine, bromine, and iodine, grouped because their chemical properties are similar.</p></div>");

quotes.push("<div><p><strong>Illumination</strong><br /> The general term for the application of light to a subject.  It should not be used in place of the specific quantity illuminance.</p></div>");

quotes.push("<div><p><strong>IR</strong><br /> Infra-red is the invisible portion of the electromagnetic spectrum that lies between about 0.75 and 1000 micro meters. Radiation in the near-infrared (0.75 - 3 micro meters) produces a sensation of heat.</p></div>");

quotes.push("<div><p><strong>Lux</strong><br /> The SI unit of luminous incidence or illuminance, equal to ONE lumen per square meter.</p></div>");

quotes.push("<div><p><strong>Lumen</strong><br /> The SI unit of luminous flux, equal to the luminous flux emitted per unit solid angle by a standard point  source having a luminous intensity of 1 candela.</p></div>");

quotes.push("<div><p><strong>NA</strong><br /> Numerical aperture is the sine of the vertex angle of the largest cone of meridional rays that can enter or leave an optical system, multiplied by the refractive index of the medium in which the cone is located.</p></div>");

quotes.push("<div><p><strong>Paraboloidal Reflector </strong><br /> A concave mirror that has the form of a paraboloid of revolution. All axial, parallel light rays are focused at the focal point of the paraboloid without spherical aberration, and conversely all light rays emitted from an axial source at the focal point are reflected as a bundle of parallel rays without spherical aberration.</p></div>");


quotes.push("<div><p><strong>SI</strong><br /> Systeme Internationale d'Unites, the international metric system of units.</p></div>");


quotes.push("<div><p><strong>Steradian</strong><br />The unit solid angle subtended at the center of a sphere by an area on its surface equivalent to the square of the radius; the unit of solid angular measurement, often used in problems of illumination.</p></div>");


quotes.push("<div><p><strong>UV</strong><br /> ultra violet light is the invisible portion of the electromagnetic spectrum that lies between 1 and 400 nano meters. (UVa 320 -400; UVb 280 - 320; UVc 100-280) UVc light in oxygen produces ozone which is toxic. UVb causes sun burn and skin irritation.</p></div>");


document.write(quotes[(Math.floor(Math.random() * quotes.length))]);