Sparkplug/pressure sensor device

A transducer for measuring stress waves indicative of characteristics of combustive events present within an internal combustion engine, said transducer comprising:

• a ceramic cylinder;
• a first electrode coaxially surrounded by said ceramic cylinder, and exposed at both a first and second end of said ceramic cylinder;
• a magnetized ferromagnetic collar surrounding and adhered to a section of said ceramic cylinder, said collar comprising a threaded section appropriate for insertion into threaded apertures present in internal combustion engine cylinder heads, and a bolt section appropriate for receiving standard sparkplug wrenches in a manner that allows said transducer to be inserted into said cylinder head;
• a second electrode electrically conductive with and attached to said magnetized ferromagnetic collar, said second electrode positioned near said second end of said ceramic cylinder to form a spark gap between said first and second electrodes;
• and
• a wire coil wound on a bobbin, said bobbin removably surrounding said magnetized ferromagnetic collar, said wire coil terminating in signal conductors directed away from said transducer, said wire coil and said bobbin encased in a pliable boot, said boot configured to receive said first end of said ceramic cylinder and said first electrode exposed therein, and to position said coil around said magnetized ferromagnetic collar, said boot further encasing said signal conductors and directing said conductors away from said transducer;
• wherein said combustive events impart stress waves into said ceramic cylinder and said stress waves travel into said magnetized ferromagnetic collar and therein generate magnetic field fluctuations that in turn generate current flow in said wire coil, the said current flow having timing and amplitude characteristics indicative of said characteristics of said combustive events.