The technique to measure spark plug temperature in an engine combustion chamber was developed. As for this technique, the infrared image of a spark plug in a visualization engine is captured with an IR camera. The visualization window which stands up to the environment of the combustion chamber which reaches 100 atm and 2000°C is attached, and this technology can measure a plug temperature to drive in the high load. Furthermore, this technology can measure a change in plug temperature in every cycle.
