High Pressure Mercury Vapour Lamp Pdf

Low pressure and high pressure low pressure sodium lamps are highly efficient electrical light sources but their yellow light restricts applications to outdoor lighting such as street lamps where they are widely used.

High pressure mercury vapour lamp pdf.

While many applications are ideal for mercury vapor lamps they are being challenged by the higher efficiency and better color balance of metal halide. High pressure mercury vapor lamps are commonly used for general lighting purposes. The mercury vapor raises the gas pressure and operating. New high power amalgam lamps are significantly more powerful than low pressure lamps.

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 heat generated by the arc then vaporizes the mercury and sodium. 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. Two varieties of such lamps exist.

The mercury vapor fluorescent lamps can be either of low pressure lp or medium pressure mp i e gas pressure inside the lamp with nominal power that may vary in the ranges 4 115 w and 400 17 000 w philips 2017 respectively. A sodium vapor lamp is a gas discharge lamp that uses sodium in an excited state to produce light at a characteristic wavelength near 589 nm. The lamp is an improvement over the lps lamp in that it has more acceptable color with the great efficiency of the sodium lamp. The uv irradiation power can be as high as approximately 30 of the nominal power.

Later cooper hewitt mercury vapor tubes and historic fixture. Liquid mercury droplets collect at the lamp s cold spot once the mercury droplets reach their peak temperature maximum uvc output occurs. They emit primarily in the blue and green. In medium pressure mercury vapor lamps the lines from 200 600 nm are present.

In a high pressure sodium lamp a compact arc tube contains a mixture of xenon sodium and mercury. The arc then heats up the mercury and the mercury vapor then lights giving the lamp a bluish color. 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. High pressure sodium lamp hps lamp the hps lamp is the most ubiquitous lamp for street lighting on the planet.

Medium pressure lamps produce the greatest uv output per unit length of lamp of the 3 lamp types. This coating covers more than 70 of the diameter of the lighted length of the lamp. The lamps can be constructed to emit primarily in the uv a around 400 nm or uv c around 250 nm.