High Pressure Mercury Lamp Construction

Again transition of the electrons requires least amount of input energy from a colliding electron.

High pressure mercury lamp construction.

1901 the first commercial mercury vapor lamp peter cooper hewitt new york city had a history of innovations in other fields and when he set about on the project of the mercury vapor lamp in 1898 it only took 3 years to develop the first reliable lamp with a acceptable color of light. Two varieties of such lamps exist. 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. Most models produce a bluish white light.

The tube contains a few milligrams of mercury and around 25 50 torr of pure argon as a buffer gas to carry the discharge while the lamp warms up producing. Ushio germicidal lamps are low pressure mercury arc lamps that emit radiation peaking at 253 7nm uv c. Mercury vapor lamps have found the greatest use in industrial applications and outdoor lighting because of their low cost and long life and lamp sizes of up to 1 000 watts. The lamp is an improvement over the lps lamp in that it has more acceptable color with the great efficiency of the sodium lamp.

Mercury vapor lamps are gas discharge lamps that uses an electric arc through vaporized mercury to produce light. Mercury vapor lamps were the first high intensity discharge lamps to be commercially available for a wide variety of lighting applications. High pressure mercury vapor lamps are commonly used for general lighting purposes. At the heart of the lamp is an arc tube which is fabricated from quartz with a tungsten electrode disposed at either end.

In case of fluorescent lamp the mercury vapour pressure is maintained at lower level such that 60 of the total input energy gets converted into 253 7 nm single line. As pressure increases the chance of multiple collisions gets increased. In medium pressure mercury vapor lamps the lines from 200 600 nm are present. Because mercury lamps are so prevalent in current outdoor lighting and still safe when properly installed in a serviceable fixture the need for these products will.

The lamps can be constructed to emit primarily in the uv a around 400 nm or uv c around 250 nm. Figure 1 a typical high pressure mercury lamp. They emit primarily in the blue and green. 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.