Improving accuracy of benzene detection based on optical atmospheric composition measurement technology

To improve the measurement accuracy in the optical measurement of benzene based on differential absorption technology, three key factors that affect the measurement results, namely, the difference of diode response, the noise in differentials and cross sections, are analyzed respectively and the solutions to reduce the adverse effect of the three factors, diode response correction, cross section smoothing and differential smoothing are introduced and described. The test results show that with the correction of diode response the measurement accuracy can be improved by around 1.5%. Noises in cross sections and differentials have relatively higher impact on the at lower concentration levels. At lower concentration levels, the measurement accuracy can be improved by as much as 30% with the smoothed cross sections, and the improvement of as high as 23% can be expected with the smoothed differentials. At higher concentration levels, the measurement accuracy can be improved by as 1% to 2% with the smoothed cross sections, and the improvement of 2% to 4% can be expected with the smoothed differentials. Generally speaking, the measures taken in this paper can improve the measurement accuracy of benzene dramatically.