Dispersed light sensor for air purity monitoring in operating theatre

摘要

The sensor has a modulated light source (12), e.g. a laser diode, coupled to a measuring volume (15), with a photodetector (18), e.g. a photodiode for detecting the dispersed light component. The photodetector is positioned on the opposite side of the measuring volume to the light source and receives the dispersed light directly, without an intermediate imaging lens. A number of photodetector elements may be arranged in a ring around the undispersed light beam, which may be received by a light-trap.