separated flame

in flame spectroscopy
Also contains definition of: shielded flame in flame spectroscopy
https://doi.org/10.1351/goldbook.S05612
In a @P04815@, sometimes provision is made to screen the observed portion of the flame gases from direct contact with the surrounding air. This may be done either mechanically by placing a tube on top of the burner around the flame, which produces a zonal separation (separated flame), or aerodynamically by surrounding the flame with a sheath of @I03027@ that emerges from openings at the rim of the burner top (shielded flame).
Source:
Orange Book, 2nd ed., p. 166 [Terms]