The D-R 290 Continuous Opacity/Dust Monitor is used for continuous opacity or dust monitoring of flue gas in stacks and ductwork. According to TA Luft and 13. and 27. BlmSchV the D-R 290 Continuous Opacity/Dust Monitor is suitable for systems firing coal, fuel oil or a mixture of fuels converter plants, asphalt mixing plants and cement production plants any other type of plant requiring quantitative monitoring of opacity or dust concentrations. In the D-R 290 Continuous Opacity/Dust Monitor results can be measured as opacity or optical density.
The D-R 290 Continuous Opacity/Dust Monitor operates according to the principle of autocollimation (double-pass). The light beam crosses the measuring path twice. The system measures and evaluates the attenuation of the light beam caused by the dust in the measuring path.
The Opacity can be compared with the attenuation of light and shows the percentage of absorbed light. The Opacity measurement is used mostly in the USA and Asia. The advantage of Opacity is that the measuring devices must not be calibrated.