60266 - Acoustic Pyrometry Robustness to Time of Flight Estimation Errors 

Acoustic pyrometry is a widely used technique for contactless temperature measurement. This technique is based on the measurement of the time of flight of an acoustic wave through a medium. If multiple emitter-receiver couples are used, a reconstruction of a temperature map is also possible through some computational procedure.This technique is particularly suitable when large sections and mid-low temperatures are involved. It has several advantages such as a relatively high frequency response, no interactions with the flow and a limited equipment cost. On the other hand, many effects may reduce its accuracy. The effect of the inaccuracy in time of flight estimation on the capability to reconstruct a temperature map is studied here via a statistical approach. It turned out that when no time of flight inaccuracy is considered, the temperature reconstruction error can be lowered by simply increasing the number of cells in which the estimation is performed. However, when errors in the time of flight estimation are considered a different behavior is observed and an optimal configuration which minimizes the estimation errors was found. The robustness of the method can be increased by using a proper system configuration, thus containing the estimation errors of the temperature profile close to those of other well-established methods.