High Pressure Mercury Vapour Lamp Pdf

Two varieties of such lamps exist.

High pressure mercury vapour lamp pdf.

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. In medium pressure mercury vapor lamps the lines from 200 600 nm are present. They emit primarily in the blue and green. This coating covers more than 70 of the diameter of the lighted length of the lamp.

In a high pressure sodium lamp a compact arc tube contains a mixture of xenon sodium and mercury. New high power amalgam lamps are significantly more powerful than low pressure lamps. The lamps can be constructed to emit primarily in the uv a around 400 nm or uv c around 250 nm. High pressure mercury vapor lamps are commonly used for general lighting purposes.

Liquid mercury droplets collect at the lamp s cold spot once the mercury droplets reach their peak temperature maximum uvc output occurs. The mercury vapor raises the gas pressure and operating. Even though more cleaning may be required for medium and amalgam lamp based systems because they have a smaller number of lamps in the uv unit these systems can. The heat generated by the arc then vaporizes the mercury and sodium.

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 xenon gas which is easily ionized facilitates striking the arc when voltage is applied across the electrodes. The uv irradiation power can be as high as approximately 30 of the nominal power. 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.

Another low pressure mercury lamp option is our standard and high output ho uvc lamps that use mercury vapor to emit uvc light. The lamp is an improvement over the lps lamp in that it has more acceptable color with the great efficiency of the sodium lamp. 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. Later cooper hewitt mercury vapor tubes and historic fixture.

The arc then heats up the mercury and the mercury vapor then lights giving the lamp a bluish color. 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. Medium pressure lamps produce the greatest uv output per unit length of lamp of the 3 lamp types.