Abstract
A description is given of a photometer designed for the measurement of total ozone in the atmosphere fromthe solar light scattered by the zenith sky. The instrument uses four interference filters and a photocell. It wascompared to other photometers, specially the Dobson spectrophotometer, in a 1974 field test at Belsk,Poland. The results of the intercomparison are detailed.In agreement with the opinion of several authors, it is concluded that total ozone measurements should beassociated with other atmospheric measurements so that information can be obtained on the influence ofaerosols on the diffusion and absorption of light. Such data, even if they are unable to eliminate errors, atleast are able to identify those conditions required for getting correct measurements.
