A light scattering photometer has been used to measure the diesel particulate emission from a vehicle to assess the capability of this instrument by comparing with the results from the traditional filter collection method and also with an opacimeter.
Tests were conducted on a diesel vehicle mounted on a chassis dynamometer with its exhaust directed to a double dilution tunnel. Different types of test were carried out, including steady speed tests at different engine loads and transient tests.
It was found that the correlation between the average particulate mass concentrations determined from the photometer and the filters changed with engine operating conditions.
Comparison between the real-time outputs from the photometer and the opacimeter showed an excellent agreement in their particulate emission patterns measured during the transient tests.
In conclusion, the photometer demonstrates a good potential in its application to diesel particulate measurements. Nevertheless, care must be taken when analysing the data since its output is likely to be affected by the physical and optical properties of the particulates.