Recent Advances in the Detection of Knock in S.I. Engines

Problem areas of general applicability in the field of detection of knock in commercial engines are discussed. These include (a) the expedients adopted to reduce the effect of noise on the sensibility of the measuring instrument, (b) the characteristics of the pass-band electronic filter employed in this type of instrumentation and possible distortion effects, (c) the type and mounting of the transducer employed, with emphasis on devices outside the combustion chamber, and (d) the interpretation of the phenomena as detected with the devices used and its relation to the energy released from knock and the danger of mechanical damage.