An acoustic pyrometer measures the average gas temperature across a wide
space of known distance, especially turbulent, high temperature gas loaded
with caustic particulates. It includes an acoustic signal generator that
generates a high amplitude acoustic signal with a short rise time and a
detector positioned adjacent the signal generator that detects the onset
of the acoustic signal in the signal generator and generates a first
electrical signal corresponding in time to the onset of the acoustic
signal in the signal generator. A receiver, positioned across the space
from the signal generator, receives acoustic signals from the space and
generates electrical signals corresponding to amplitude and frequency of
the acoustic signals received in the receiver. A signal processor
processes the electrical signals from the receiver to distinguish the
onset of the acoustic signal from background noise in the space as
detected in the receiver, and processes the electrical signals from the
receiver to produce a distinct differentiation between background noise
and the onset of the acoustic signal in the receiver. The signal processor
then compares the time of the onset of the acoustic signal in the receiver
with the onset of the acoustic signal in the signal generator to determine
the transit time of the acoustic signal to traverse the space, and also
calculates the temperature of the gas in the space based on the transit
time.
