New Measuring Method for Blue and White Smoke in Diesel Engines by a Digital Camera System

The blue and white smoke (cold smoke) emitted from diesel engines during warm up at low temperatures and idling conditions contains pollutant gases which irritate eyes and nose, and reductions in this irritating, odorous gas have become important with the increasing numbers of DI diesel engine vehicles. To assess the blue and white smoke a qualitative assessment method is necessary, though, there are no simple and exact measuring methods.

In this study a new assessment method using a digital camera and photo analysis system with a computer is introduced. With this method the luminance of the cold smoke is displayed as 8 bit data, and a quantitative evaluation is simple, when the influence of sunshine is corrected for the smoke luminance. This paper describes the correction method for the sunshine illumination and the technique for taking the photographs.

It was found that the new method with the digital camera system has a good correlation with evaluations by experienced persons, and that it is simple and exact.