Working principle of fluorescent lamp pdf

This term was first coined by the british scientist sir george stokes in 1852, following his observations on the mineral fluorite which glows when irradiated with ultraviolet light. Today the term is defined as the emission of light by a substance which has absorbed radiation of. The efficiency of an equivalent tungsten lamp is about 40 lumens per watt, about three times the efficiency of an equivalent filament lamp. Rk primer of school lighting lamps and maintenance. A fluorescent lamp, or fluorescent tube, is a lowpressure mercuryvapour gasdischarge lamp that uses fluorescence to produce visible light. The normal luminous viability of fluorescent lighting frameworks is 50 to100 lumens per watt, which is a few times the adequacy of incandescent lamps with equivalent light yield. In present days, incandescent lamps are available in different wattage ratings such as 25, 40, 60, 75, 100 and 200 watts etc.

Then we connect the fluorescent tube and a starter across it. Read this article to learn about the working of fluorescence microscope. Working principle of fluorescent lamp polytechnic hub. When we switch on the supply, full voltage comes across the lamp and as well as across the starter. The basic principles of the most commonly used lamp types and the circuitry which makes them operate are. Working principle of fluorescence microscope with figure. The most common form of germicidal lamp looks similar to an ordinary fluorescent lamp but the tube contains no fluorescent phosphor. A fluorescent lamp or a fluorescent tube is a lowpressure mercuryvapor gasdischarge lamp that uses fluorescence to produce visible light.

It is possible to active quite high lighting intensities without excessive temperature rise and owing to the nature of light sources, the danger of galore is minimized. Here we connect one ballast, and one switch and the supply is series as shown. Due to operation at higher frequency, discharge process in fluorescent lamp is at higher rate. Of course most school systems wash their lighting equipment each summer, but if this is not done thoroughly, they may start. The tube is then finally sealed at low pressure with two filament electrodes each at its both ends. It is possible to active quite high lighting intensities without excessive temperature rise and owing to the. Fluorescent lamps require ballasts to provide the starting voltage and limit the electrical current during lamp operation. Because of the even distribution of the dirt over the fixture, it can go unnoticed. Fluorescent lighting has a great advantage over other light sources in any application. An electric current in the gas excites mercury vapor which produces shortwave ultraviolet light that then causes a phosphor coating on the inside of the bulb to glow. In the end, are underlined the for general lighting, fluorescent lamps are known. Fluorescent lamp and working principle of fluorescent lamp. Before going through the working principle of a fluorescent lamp, we will first show the circuit of a fluorescent lamp in other words circuit of tube light.

A fluorescent lamp has changed over electrical energy into useful light energy to a great deal more proficiently than incandescent lamps. The basic principles of the most commonly used lamp types. A fluorescent lamp basically consists of a long glass gas discharge tube. In addition, rather than being made of ordinary borosilicate glass, the tube is made of fused quartz or sodalime glass which allow the 185nm andor 253. Its inner surface is coated with phosphorous and is filled with an inert gas, generally argon, with a trace of mercury. In fluorescent lamps the current flows through a gaseous conductor, instead of a solid state conductor where electrons simply flow from negative end to the. The fluorescent tube produces visible light by the process of fluorescence.