Abstract: A method and apparatus for analyzing a picture of an effluent such as a smoke plume or dust cloud to determine the opacity of the effluent. The picture of the effluent is first broken down into pixels. Each pixel corresponding to the effluent is identified and the color of each effluent pixel is analyzed to calculate the opacity of that effluent pixel. An opacity value for the entire effluent is extrapolated based on the opacity values of each effluent pixel.

Abstract: Method and apparatus for measuring radiant energy, particularly relatively high energy levels of coherent radiation, in which the energy impinges upon an absorber surface, the energy transferred from the absorber surface to a fluid coolant in thermal association with the absorber surface, and the energy carried away by the coolant measured by means of a temperature difference measuring device, preferably a thermopile, positioned in thermal contact with a portion of the inlet leg of the coolant conduit and the outlet leg thereof, in order that high energy levels may be measured at a cool absorber surface while flowing relatively small amounts of heat energy through the temperature difference measuring means.