DEVICE FOR MEASURING FUEL CONCENTRATION

摘要

PROBLEM TO BE SOLVED: To provide device for measuring a fuel concentration in which measurement errors are reduced and the device is miniaturized to facilitate the arrangement.SOLUTION: A device for measuring a fuel concentration irradiates a measuring optical path LP in a combustion chamber C of an internal combustion engine with a measuring light ML, and measures the fuel concentration of a combustion chamber C from the intensity of a signal light SL transmitting a measuring optical path LP, and includes a half-mirror 25a as a branching part for branching reference light RL from the measuring light ML before incident to the measuring optical path LP. The half-mirror 25a which is the branching part is arranged inside the internal combustion engine.SELECTED DRAWING: Figure 3