A study of a transport emission monitoring tool -remote sensing system

摘要

An infrared remote sensing system for monitoring urban transport emissions has been developed. This system consists of three main components, i.e., an IR source, a high sensitivity IR detector, and an electronic data acquisition unit with in-house computer software. From the Beer-Lambert Law, it was known that infrared signals from the detector should be influenced by the emission gas concentrations, the intensity of the source, and the distance between the source and the detector. In order to operate this remote system over wide varieties of urban road and the ambient conditions, a series of off-road laboratory experiments was made with different IR source intensities and different operating distances between the IR source and the detector. The infrared signal was a function of the IR source voltage(V), the distance(D) between the source and the detector, and the gas concentrations. This calibration function was derived from data obtained in systematic laboratory experiments. The calibration function was programmed into the data acquisition unit, enabling rapid evaluation of passing vehicles. Test were carried out at four cities in New Zealand. The equipment operated stably and consistently.