Recording local fluctuations of physicochemical parameters in a combustion wave in condensed systems

A method for recording fluctuations of physicochemical parameters in a combustion wave in condensed systems is proposed that makes it possible to estimate the frequency of these fluctuations experimentally. Experiments with a Zr + WO$_3$ pyrotechnic mixture using this method show that in the combustion wave there are fluctuation modes with frequencies $\approx$200 and $\approx$20 Hz corresponding to characteristic dimensions of heterogeneities of the system of order 0.1 and 1 mm, respectively.