Patent ID: 7936460

Claim:
A sensor unit in an exhaust gas analyzer, the sensor unit being installed in an exhaust path of exhaust gas and comprising a sensor base including an exhaust gas passage opening through which exhaust gas passes, an irradiation portion from which laser light is applied and a light receiving portion, the irradiation portion and the light receiving portion being provided at the sensor base, wherein laser light applied from the irradiation portion to exhaust gas in the exhaust gas passage opening is received by the light receiving portion and a concentration of a component contained in the exhaust gas is measured based on the received laser light, wherein the exhaust gas passage opening comprises a through hole through which exhaust gas passes formed in an adjustment ring detachably fitted to an aperture formed in the sensor base, and wherein the adjustment ring includes a circumferential face in which a laser-light passage portion is formed for allowing laser light applied from the irradiation portion to arrive at the light receiving portion.