A FAST-RESPONSE UV-ABSORPTION OZONE PHOTOMETER USING A DIFFERENTIALLY-PHASED TRIPLE-CELL SYSTEM

A new fast-response ozone photometer which uses ultraviolet (UV)-absor ption is described. Its three UV-absorption cells each cycle among thr ee modes: reference, sample and transition modes. The three cells are differentially phased, enabling the ozone concentration to be determin ed in a cell in one second without interruption. The system is effecti ve for measurements requiring a fast response, such as measurements on aircraft. We made a trial instrument that adopts this system and conf irmed its theoretically predicted operation. The trial instrument show ed a significantly faster response than earlier types of ozone photome ters. This system may be applicable to other gas measurements that use s UV-absorption.