Patent ID: 6386755
Filing Date: 2002-05-14
Classification: G01K

Abstract:
An acoustic pyrometer, comprising:means for generating an acoustic signal with a high amplitude sudden onset; means positioned adjacent said signal generating means for detecting the onset of said acoustic signal in said signal generating means and generating a first electrical signal corresponding in time to said onset of said acoustic signal in said signal generating means; a receiver positioned across a space of known distance from said signal generating means for receiving acoustic signals traversing said space from said acoustic signal generating means in a transit time that is a function of temperature of gas in said space, and for generating electrical signals corresponding to amplitude and frequency of said acoustic signals received in said receiving means; and means for processing said electrical signals from said receiver to distinguish the onset of said acoustic signal from background noise in said space as detected in said receiving means, and for comparing the time of said onset of said acoustic signal in said receiving means with said onset of said acoustic signal in said signal generating means to determine said transit time for said acoustic signal to traverse said space, and for calculating said temperature of said gas in said space based on said transit time, said signal processing means includes a time of flight module for determining the transit time of said acoustic signal to traverse said space; wherein said time of flight module produces a distinct differentiation between background noise and said onset of said acoustic signal in said receiver, said time of flight module including: a digital prefilter for modifying said signal received in said receiver to a modified signal having an increased ratio of amplitudes of said acoustic signal to said noise; and a stochastic model of said signal for determining the time of onset of said acoustic signal in said receiver.