Abstract: In one aspect, the present invention relates to a device quantifying absolute amounts of ingredients of a plume. In one embodiment, the device comprises a source for emitting a beam of light and transmitting the emitted light through the plume to a surface on which the transmitted light is scattered, a detector for acquiring an image of the exhaust plume, the acquired image containing information of absorption of the scattered light scattered from the surface, and a processor for processing the acquired image to determine an absolute amount of at least one of components of the exhaust plume.