Abstract
It's clear that the merit of visualized information in combustion chamber results in understanding the many effective physical parameters. But this system needs the modification of an engine and big power laser, very high speed camera. Additionally, it need the much time to transfer the know how for the real engine optimization and simulation models. On-board measurement system has a big merits because it easy to transfer the real engine without modification. Merits are the time and cost of these system. Several systems are commonly installed in a spark plug. This reports deals about the typical kind of method to know the gas temperature under motoring and firing condition using I.R. absorption method.
