Fluorescent lamps

 

— lamps of this type are equipped with a sealed tube, covered from the inside with a layer of special material and filled, most often, with mercury vapor. The glow occurs due to an electric discharge inside the tube — the inner coating (phosphor) reacts to it and begins to glow. The advantages of all luminescent models are low power consumption and long service life, the disadvantages are uneven colour reproduction, rather high cost, the inaccessibility of some special functions (for example, brightness control), as well as environmental hazard due to the use of mercury vapor.