Abstract: A method and apparatus is provided for the sensing, collection, and analysis of information on combustive and mechanical events occurring within an operating internal combustion engine through the measurement of mechanical stress waves present within the engine. The system includes a magnetostrictive sensor placed in mechanical compliance with the engine, preferably the engine block, which detects and translates stress waves into an electrical signal that is filtered and amplified for recording and/or for analysis. Information regarding the frequency, amplitude, and timing changes within the signal is utilized to characterize the ordinary operation of the engine and to identify anomalous events. The system includes a means for maintaining a signal record and comparing signal features with past records for a particular engine or with standard signal features associated generally with certain engine events.

Abstract: A pressure transducer suitable for use in measuring the pressures created by the combustive events that occur in internal combustion engines. The transducer utilizes the magnetostrictive effect to measure stress waves present in magnetized metallic components associated with sparkplug devices typically placed in apertures into internal combustion engine cylinders. The present invention includes a replacement sparkplug device that incorporates a pickup coil for measuring magnetostrictive events within the magnetized metal components of the sparkplug device and alternatively a sparkplug boot cover that separately incorporates a removable pickup coil for measuring the stress waves. In either embodiment, the present invention utilizes the magnetostrictive sensor signals measured as a basis for identifying internal combustion cylinder pressures and for identifying the characteristics of the ignition events within the cylinder.