Low Pressure Mercury Lamp Spectrum

The german physicist leo arons 1860 1919 studied mercury discharges in 1892 and developed a lamp based on a mercury arc.

Low pressure mercury lamp spectrum.

Nyc subways were still using original mercury arc rectifiers to convert ac to dc power up until the end of the 20th century. Low pressure mercury lamps are very similar to a fluorescent lamp with a wavelength of 253 7 nm 1182 5 thz. Right around 1900 the mercury arc rectifier was developed this luminous device was very important for power conversion. These early low pressure lamps used a lot of mercury today s lamps use a tiny amount of mercury.

Lp lamps operate at about 40 c and have one useful disinfection output peak at 254nm. Rather than a cold spot the lamp s amalgam spot on pellet regulates mercury vapor pressure during operation and yields up to three times the uvc output of a standard low pressure mercury lamp of the same length. Aquafine lp lamps are considered to be monochromatic or single peak output lamps. The most common form of germicidal lamp looks similar to an ordinary fluorescent lamp but the tube contains no fluorescent phosphor in addition rather than being made of ordinary borosilicate glass the tube is made of fused quartz or vycor 7913 glass.

Charles wheatstone observed the spectrum of an electric discharge in mercury vapor in 1835 and noted the ultraviolet lines in that spectrum. In 1860 john thomas way used arc lamps operated in a mixture of air and mercury vapor at atmospheric pressure for lighting. Two varieties of such lamps exist. Black lamp is a low pressure mercury lamp whose envelope is covered with a phosphor such as strontium fluoroborate or barium disilicate.

An electric current in the gas excites mercury vapor which produces short wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow a fluorescent lamp converts electrical energy into useful light much more efficiently. A fluorescent lamp or fluorescent tube is a low pressure mercury vapor gas discharge lamp that uses fluorescence to produce visible light. 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 type of phosphor determines the spectral distribution of the lamp output forbes et al 1976 figure 16 4 shows a typical spectral distribution for λ 500 nm from a black lamp as well as the solar spectrum at two zenith angles where all curves have.

Low pressure discharge lamps. Fluorescent lamps a heated cathode lamp the most common lamp in office lighting and many other applications produces up to 100 lumens. Aquafine standard low pressure lp and amalgam low pressure lp lamp spectrum. Low pressure lamps have working pressure much less than atmospheric pressure.

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. Amalgam lamps use a mercury amalgam mix to control mercury vapor pressure. Low pressure mercury lamps have been manufactured in jelight company inc. Facts about aquafine standard low pressure lp lamps.