Measuring mass concn. to ascertain extinction of aerosol - using photometer receiving proportional measuring signal along at least two optical paths

摘要

A measuring signal proportional to the mass concn. is received sequentially along at least two optical paths, one being longer than the other. Taking into consideration the path lengths and the same extinction coefft. for both signals a null point measuring signal for a value without an aerosol is determined and compared with the rated value for the null point measurement signal for use as the basis for the following extinction measurements. A reflection arrangement (1) is used to return the radiation in the medium to be measured. A variable slide arrangement (3) is provided by a computer controlled pneumatic reciprocable piston with the reflector at one end. The latter is moved by the piston to provide two different optical paths w.r.t. the radiation generating and receiving arrangement. USE/ADVANTAGE - Testing without direct engagement. Long term measuring including in strongly contaminated atmospheres.