High Pressure Mercury Vapour Lamp Pdf

The lamps can be constructed to emit primarily in the uv a around 400 nm or uv c around 250 nm.

High pressure mercury vapour lamp pdf. This coating covers more than 70 of the diameter of the lighted length of the lamp. Another low pressure mercury lamp option is our standard and high output ho uvc lamps that use mercury vapor to emit uvc light. 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 xenon gas which is easily ionized facilitates striking the arc when voltage is applied across the electrodes.

The lamp is an improvement over the lps lamp in that it has more acceptable color with the great efficiency of the sodium lamp. Medium pressure lamps produce the greatest uv output per unit length of lamp of the 3 lamp types. Two varieties of such lamps exist. The arc then heats up the mercury and the mercury vapor then lights giving the lamp a bluish color.

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. 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. Later cooper hewitt mercury vapor tubes and historic fixture.

High pressure sodium lamp hps lamp the hps lamp is the most ubiquitous lamp for street lighting on the planet. 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. 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. Liquid mercury droplets collect at the lamp s cold spot once the mercury droplets reach their peak temperature maximum uvc output occurs.

In medium pressure mercury vapor lamps the lines from 200 600 nm are present. The uv irradiation power can be as high as approximately 30 of the nominal power. They emit primarily in the blue and green. In a high pressure sodium lamp a compact arc tube contains a mixture of xenon sodium and mercury.

High pressure mercury vapor lamps are commonly used for general lighting purposes. 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. The mercury vapor raises the gas pressure and operating.