Infrared radiation from a Bunsen flame.

Many observers have studied th e infrared emi sion of a Bunsen flame [11. 2 The strongest band ocem s at about 4.4 Il and is produced by carbon dioxid e. Other bands have been found a t 0.95, 1.45, 2.0, and 2.8 Il , and are a ttributed to carbon dioxide and water vapor. Very little radiation has been observed in the region beyond 7 Il . In the visible and ultraviolet regions of the spectrum, considerahle progress has been made in the study of flames [21. By the use of instruments with good resolution and by detecting with pho tographic plates that average out the fluctuations of the flame, many band systems have been identified . The band systems include such atomic groups as OH, ON, NO, OH , and NH. The ques tion may be asked why the spectra of such groups have not been 'observed in the infrared region. The probable reason is tha t sufficiently high resolution has not been applied in the infrared region to separate properly the spectra of the different groups. Also, slight fluctuations in the flames make i t difficult to obtain accura te meas-