Theoretical Principles on the Restricted Breathing Properties or Materials in Potentially Explosive Environments and Their Utilization

Electrical restricted breathing material is material which can be used for practice in explosion-endangered areas under certain conditions. It can be used in cases where the occurrence of explosive gas-air or vapor-air mixtures is safely limited to a short time. In such cases with a time-limited danger of explosion, the demand for using completely explosion-proof material is not always economically tenable. Here the use of restricted breathing material, which safely prevents the penetration of the explosive mixture to those positions which might cause ignition, is more economical. The safety depends above all upon the imperviousness to the penetration of gases and vapors. The foundations, preconditions, theory, and testing methods for restricted breathing material are discussed. The restricted breathing factor S is discussed as characteristic size, and its dependence upon the low explosion limit, the diffusion constant, and the boiling temperature of the explosive mixture is pointed out. At the same time, it is shown how the suitability of the material can be checked with simple measuring methods.