Piezoelectric pressure sensor suitable for sensing pressure at high temperatures

A piezoelectric pressure sensor for detecting pressure in a combustion chamber of an internal combustion engine, comprising:

• a backing plate having a planar surface, said backing plate being secured within a housing;
• a resilient prestress plate having a planar surface and being stacked on said backing plate, said resilient plate being formed of silicone elastomer;
• a sensor element having a planar surface and being stacked on said resilient plate, said sensor element being composed of a piezoelectric material formed by mixing lead titanate and lead zirconate in a molar ratio in the range of from about 40:60 lead titanate:lead zirconate to about 60:40 lead titanate:lead zirconate;
• a thermally insulating plate having a planar surface and being stacked on said sensor element;
• and
• a diaphragm plate having a planar surface and being stacked on said thermally insulating plate, said diaphragm plate also being secured to said housing, and said diaphragm plate being exposed to combustion atmosphere and being adapted to transmit a pressure being determined onto said sensor element.