Photometry Testing
Photometry uses modern science to measure the visible light in terms of its perceived brightness to human vision. The basic unit of photometry is lumen (lm). The inverse square law and cosine law are the two main laws that are used in photometry. The inverse square law states that the intensity per unit area on the surface varies ins inversely proportional to the square of distance between the source and surface. While on the other hand, the cosine law indicates the intensity of light on a surface of a fixed area varies with the incident angle. Technically, the intensity falls off as the cosine of the angle.
“Light” is simply the radiation within this visible range. Hence, light has a wavelength range which human beings can see and observe. All radiation has its own energy. And light has its own energy to stimulate eyes. The human eye can detect radiations having wavelength ranging from 370 nm to 780 nm. The human eye is unable to stimulate the energy of radiation whose wavelength is more or less than the range of light. The radiation having wavelength more than light is known as infrared radiation. Whereas the radiation which having wavelength less than light is known as ultra-violet radiation. Photometry neither includes infrared nor ultraviolet radiations. Reflectance Photometry A reflectance photometer measures the reflectance of light from the surface. The reflectance of light is a function of wavelength. The white light is illuminated on the surface of a substance. The reflected light from a substance is measured after passing through a monochromator. The color of the surface can be measure by measuring the wavelength of reflected light. This method is used in paint industries to characterize the color of a surface. We at ITC India Pvt. Ltd. provide Photometry Testing Services for all kinds of LED lights and luminaries. Our Photometry Testing mainly includes testing against LM 79 and LM 80. Apart from these standards, we also provide LED and luminaire testing services against many other standards like IEC 60598, IEC 60529, IEC 60068 etc. At ITC India, Medical Device Testing, Electrical/Electronice Equipment testing, Environmental testing, NDT testing and many other Testing services are also available. For more information, contact [email protected] or fill the below form to get your Testing QUOTE today. |
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