Abstract
A laser speckle photographic technique is used for measuring temperature profile inside a gaseous flame. Patrick et al. see Appl. Opt., vol.23, p.1055, 1984, used speckle photography to obtain full field temperature data. In his paper for cited experimental conditions the fringe spacing becomes large and indistinct as distance from the centre of the flame exceeds 0.7 cm. Consequently the temperature data was not available for radii beyond this point. The authors have optimized the experimental parameters to measure temperature field over the entire volume of the flame. Experimental results are compared with the values measured by thermocouple. Very good agreement is seen between the temperature measured by thermocouple and speckle photography.