A generic term for a device designed to produce electromagnetic radiation in the form of light, heat, ultraviolet energy, or a combination of the three. The term lamp is applied to the entire range of sources, including flame sources (such as kerosine lamps or gas lamps with Welsbach mantles), incandescent sources, and electric arc discharge sources. Used with a modifier, such as ultraviolet, infrared, or sun, the term lamp is used to indicate sources that radiate energy in the ultraviolet or infrared portions of the electromagnetic spectrum (plus some radiation in the visible part of the spectrum).