Abstract
Temperature measurements have been performed in a low-pressure flame by the technique of diode laser induced atomic fluorescence. The
experiments were done in a near-stoichiometric flat-flame of premixed
methane, oxygen and nitrogen, at a pressure of 5.3 kPa. Indium atoms
were seeded to the flame and probed using blue diode lasers; the
lineshapes of the resulting fluorescence spectra were used to determine
the flame temperature at a range of heights above the burner plate. The
particular issues associated with the implementation of this
measurement approach at low pressure are discussed, and it is shown to
work especially well under these conditions. The atomic fluorescence
lineshape thermometry technique is quicker to perform and requires less
elaborate equipment than other methods that have previously been
implemented in low-pressure flames, including OH-LIF and NO-LIF. There
was sufficient indium present to perform measurements at all locations
in the flame, including in the pre-heat zone close to the burner plate.
Two sets of temperature measurements have been independently performed
by using two different diode lasers to probe two separate transitions
in atomic indium. The good agreement between the two sets of data
provides a validation of the technique. By comparing thermocouple
profiles recorded with and without seeding of the flame, we demonstrate
that any influence of seeding on the flame temperature is negligible.
The overall uncertainty of the measurements reported here is estimated
to be +/- 2.5% in the burnt gas region.
Original language | English |
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Pages (from-to) | 907-914 |
Number of pages | 8 |
Journal | Applied Physics B: Lasers and Optics |
Volume | 93 |
Issue number | 4 |
DOIs | |
Publication status | Published - 31 Oct 2008 |
Keywords
- diode laser
- atomic fluorescence
- temperature
- measurements
- low-pressure flames