Test gas generator for calibration of gas-measuring appts.

摘要

A device for generating a test gas with a predetermined concn. of a gas component to be detected by a measuring appts. (1), comprises two serially-connected containers. A carrier gas flows through the containers, each of which holds a calibration soln. (4). The carrier gas is concentrated with the calibration substance in an amount dependent on its vapour pressure at the operating temp. To renew the calibration soln. consumed, a stock soln. is supplied from a reservoir (21) to fill the containers in turn, counter to the direction of flow of the carrier gas. Excess stock soln. is removed into a collection container (27).