Apparatus for the photometric determination of gas concentrations

Abstract

A process and apparatus for measuring the concentration of gases in a medium are provided in which the radiation absorption of the gas in the medium is determined with the aid of a sample measurement and reference measurement. The medium with the gas is continuously passed through a measuring cell, and a reference medium not containing the measured gas is continuously passed through a reference cell. Both cells are alternately brought into the optical path between a lamp and a photoreceiver. The results of the absorption measurement in the measuring cell and the reference cell are divided. The concentration of a gas in a liquid, or ozone in water, can be measured by passing the liquid through an exchange material in a packed tower, through which a reference gas stream is passed in counterflow manner. An exchange of the measured gas occurs from the liquid stream to the reference gas stream. The absorption of the measured gas in the reference gas stream is determined alternately with the absorption of a stream of the reference gas without any measured gas, from which the concentration of the measured gas in the liquid medium is calculated. A packed column with a pressure compensating line may be provided to prevent flooding of the column and to ensure continuous operation of the exchange material.

Dependencies are inferred from the claim text.