ABSTRACT
As the raw material of rendering plants produces very odoriferous substances, air cleaning systems are usual. Five such air cleaners in normal performance were measured olfactometrically. The olfactometric efficiency of biofilters proved to be better than that of chemical scrubbers. A large difference between the relative odour concentration in the cleaned air and asserted limit values, based on older olfactometric methods confirm the necessity of a standardisation of olfactometric measurement methods.
