Application of tunable diode laser spectroscopy to the real-time analysis of engine oil economy

Tunable diode laser spectroscopy (TDLAS) of oil-derived SO 2 in automotive exhaust demonstrated acceptable repeatability in determination of oil consumption at steady-state engine operating conditions. The response time of the instrument was approximately 30 s, the time related to the flow rate of the sampling system. Instrument sensitivity is sufficient to measure SO 2 levels of 0.1-1 ppm required for the oil consumption determination