High Pressure Mercury Vapour Lamp Construction And Working

The outer bulb may be clear or coated with a phosphor.

High pressure mercury vapour lamp construction and working.

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. As pressure increases the chance of. This is different from fluorescents which use the mercury vapor arc to create a weaker light that mainly creates uv light to excite the phosphors. A low pressure sodium vapor lamp or lpsv lamp is termed as a miscellaneous discharge lamp as it possesses some characteristics of high intensity discharge hid lamps as well as it resembles fluorescent lamps in other areas.

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. When high voltage is applied we can observe that the neon gas which was originally in pink color will change into orange color by heating. In either case the outer bulb provides thermal insulation protection from the ultraviolet radiation the. Figure 1 a typical high pressure mercury lamp.

Working of mercury vapor lamp the mercury vapor and neon gas pink in color present in the bulb requires high voltage at the starting to illuminate light. Two varieties of such lamps exist. It uses an arc through vaporized mercury in a high pressure tube to create very bright light directly from it s own arc. Again transition of the electrons requires least amount of input energy from a colliding electron.

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. 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. At the heart of the lamp is an arc tube which is fabricated from quartz with a tungsten electrode disposed at either end. Basically an lpsv lamp is a gas discharge lamp that uses sodium in an excited state to produce light.

The mercury vapor lamp is similar in construction to the sodium vapor lamp. It consists of a discharge envelope enclosed in an outer bulb of.