Patent ID: 7448254

Claim:
Apparatus for measuring knocking in an internal combustion engine, comprising: a high temperature, acceleration compensated pressure transducer positioned within the cylinder of said engine and providing an output signal indicative of the combustion signal together with the knocking signal, said pressure transducer comprising two substantially identical deflecting regions, one of said deflecting regions being exposed to pressure in said cylinder while said second deflecting regions being sealed from said pressure, each of said deflecting regions generating a signal that is combined to represent said output signal; a tunable band-pass filter for filtering said output signal to provide a filtered signal indicative of only said knocking signal, said filter having a range between 500-5000 Hz centered about a frequency dependent upon the revolutions per minute (RPM) of said engine; means for processing said filtered signal and said output signal to provide a measurement of the extent of said knocking.