Gas diffusion control assembly.

摘要

A gas diffusion control assembly comprises a gas inlet (2); a restriction (3) to the rate of flow of gas or vapour from the gas inlet (2) in the form of a porous diffusion barrier extending across the gas inlet; and a polythene disc (4) for causing all gas or vapour passing out of the inlet (2) into the diffusion barrier (3) to diffuse through part of the barrier along a path with a lateral outward component relative to the direction of action through the gas inlet.