High Pressure Mercury Vapour Lamp Ppt

These lamps can be operated in any position and have low sensitivity to voltage fluctuation.

High pressure mercury vapour lamp ppt.

1906 higher pressure mercury vapor light in a fuzed quartz tube is developed kuch retschinsky siemens munich 1936 the modern high pressure mercury vapor lamp is developed type mb philips nederlands no individual names are available. The uv fraction 250 380 nm is about 30 but depending on. High pressure sodium lamp hps lamp the hps lamp is the most ubiquitous lamp for street lighting on the planet. When a mercury vapor lamp is first turned on it will produce a dark blue glow because only a small amount of the mercury is ionized and the gas pressure in the arc tube is very low so much of the light is produced in the ultraviolet mercury bands.

While many applications are ideal for mercury vapor lamps they are being challenged by the higher efficiency and better color balance of metal halide. The aperture phosphor coated lamps that jelight company produces employ the same basic design as the double bore low pressure mercury vapor lamps with the exception of a special phosphor coating. The inner surface of the lamp is coated with a fluorescent and often slightly phosphorescent coating made of varying blends of metallic and rare earth. Application areas are commercial industrial shops roadways where color redention is important.

The arc then heats up the mercury and the mercury vapor then lights giving the lamp a bluish color. A low pressure sodium vapor lamp or lpsv lamp is termed as a miscellaneous discharge lamp as it possesses some characteristics of high intensity discharge hid lamps as well as it resembles fluorescent lamps in other areas. The pressure inside the lamp is around 0 3 of atmospheric pressure. This coating covers more than 70 of the diameter of the lighted length of the lamp.

Basically an lpsv lamp is a gas discharge lamp that uses sodium in an excited state to produce light. The mercury vapor raises the gas pressure and operating voltage and the sodium vapor produces light when the pressure within the arc tube is sufficient. A typical hg high pressure discharge lamp with a power of 400 w has a wall plug efficiency of 20 i e. This phosphor technology offers better color rendition than the more efficient high or low pressure sodium vapor lamps but still falls short of metal halide and ceramic metal halide sources.

As the main arc strikes and the gas heats up and increases in pressure the light shifts into the visible range and the high gas pressure causes. High pressure mercury vapour lamps are ideal source for indoor lightning. High pressure sodium lamps are the most efficient artificial white light source with about 29 of the energy used by the lamp producing light. Blended lamps do not need any control gear for lighting and can be directly used.