In general, light spectrum could be classified into discrete spectrum
and continuous spectrum. However, both absorption and emission are the main typical pattern for discrete spectrum. Unlike the discrete way mentioned above, typical continuous spectrum, in this experiment, will be investigated. Here a slice with 500line / mm grate will be used to observe the spectrum from incandescent lamps, sunlight and candles (experimental mechanism as shown in Fig.1). While the below condition is subjected, the wavelength of first order bright fringe (bright line spectrum) emitted from mercury-containing fluorescent lamps and LED lamps could be accessed as you view from the grating, whose corresponding intensity will be displayed in Fig.2. Symbols d, l, s individually designate the grating spacing, half width of first order bright line and the distance from light source to grating.