Apparatus for measuring atmospheric opacity

摘要

The apparatus 1 comprises: a first optical limiter 3 which conveys the light emitted by a light source 2; a second optical limiter 4 which conveys the light diffused by particles suspended in the air of a zone through which passes the light flux emitted by the source; means 5 and 6 which transmit the light from the limiters to an element 7 which generates an electrical signal in proportion to the luminous intensity; and a device 8 which prevents and allows the conveying of the light along the second limiter such that the element generates an electric signal proportional to the sole quantity of light emitted by the source and an electric signal proportional to the sum of the quantity of light emitted by the source and the quantity of light diffused by the particles suspended in said zone. IMAGE