Low Pressure Mercury Vapour Lamp Diagram

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.

Low pressure mercury vapour lamp diagram.

Again transition of the electrons requires least amount of input energy from a colliding electron. As pressure increases the chance of multiple collisions gets increased. One would tip the lamp and electrical contacts on each side of the lamp would send electricity through a liquid mercury which started the lamp. Two varieties of such lamps exist.

The lamps can be constructed to emit primarily in the uv a around 400 nm or uv c around. In low pressure mercury vapor lamps only the lines at 184 nm and 254 nm are present. This coating covers more than 70 of the diameter of the lighted length of the lamp. 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 first mercury vapor lamps were in a lower pressure tube. Amalgam lamps use a mercury amalgam mix to control mercury vapor pressure. In medium pressure mercury vapor lamps the lines from 200 600 nm are present. 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.