Desenvolvimento de sensores quimicos com fibras opticas para a determinação quantitativa de fuligem e de monoxido de carbono emitidos por veiculos automotores

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

In this work were developped two portable devices for quantitative determination of automotive pollution by diffuse reflectance. One is for measurements of the smoke emissions from vehicles by diesel cycle and other for measurements of the carbon monoxide emissions from vehicle by Otto cycle. Both are of easy operation and were developed for the measurements of these pollutants directly from the tail-pipe emissions, by partial flux sampling. In the smoke device, the exhaust gases are flowing through the sample tube to the glued face of a white adhesive tape. This tape moves in front a diffuse reflectance cell with two optical fibers by action a little motor powered with a 9 V battery .The diffuse reflectance attenuation produced on the tape is proportional to the smoke concentration present in the exhaust gases. The signal is measured in the photodetection system (photodiode, amplification circuit and signal display). In the carbon monoxide sensor, the exhaust gases sampling produce a color change in the solution reagent H8Si (MO2O7)6 absorbed in a paper filter disc. The color changes from clear yellow to dark green. The diffuse reflectance attenuation produced is proportional to carbon monoxide concentration present in the exhaust gases. The signal is measured by similar way as in the smoke detector above. The smoke and carbon monoxide sensors developed correlated very well with Bosch smokemeter EFAW 68A (paperfilter disc method) and the Bosch CO analyser ETT 00814 (infrared method), respectively.

ASSUNTO(S)

fibras oticas detectores quimicos ar

ACESSO AO ARTIGO

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