Opacity measuring method for exhaust gas, involves using pair of filters with different pass band wavelength range for measurement of opaqueness of gas, whose signal values are compared automatically

摘要

The opacity of gas is measured by using a filter with a green-light pass band wavelength of about 550-570 nm. The opacity measurement is also performed with another filter with a pass-band wavelength of about 200 nm to 2 mu m which at least to some extent overlaps the green-light wavelength band. The signals from the two pass-band light measurements are compared automatically. An Independent claim is also included for opaqueness measuring device.