The Measurement of Diesel Particulate Emissions with a Tapered Element Oscillating Microbalance and an Opacimeter

A Tapered Element Oscillating Microbalance (TEOM) and the high-sensitivity light extinction type opacimeter have recently been used for continuous measurement of diesel exhaust particulates. This paper describes the comparison tests between the TEOM, a light extinction type opacimeter and a filter collection method and validates the applicability of the TEOM in the measurement of diesel exhaust emissions.

Comparison measurements were performed using the above three methods. In cruise and modal operating conditions, it was recognized that the TEOM data was well-correlated to the filter collection method, which was a standard for diesel particulate measurement. For comparisons with the light extinction type opacimeter, which had been developed for measuring low concentration exhaust smoke, it was found that the TEOM data was also correlated except for distinctive engine conditions.

In continuous measurement under modal operating conditions, it was shown that the light extinction type opacimeter is better than the TEOM method in terms of transient response and sensitivity.