Porous material crack detection

摘要

This invention provides a method for monitoring early formation of cracks in permeable or porous materials which comprises affixing a frangible fluid impermeable enclosure to the permeable or porous surface to be monitored such that a crack forming in the permeable material will destroy the integrity of the frangible fluid impermeable enclosure and provide a passage for a fluid to flow between the environment and the enclosed space, then sealing a fluid passageway in fluid communication from the enclosed space to a source of pressure different than ambient at the permeable material and to a pressure sensor; then imparting a pressure different than ambient to the enclosed space through the fluid passageway and thereafter monitoring the internal pressure in the enclosed space and fluid passageway with a pressure sensor such that a crack in the permeable material will destroy the integrity of the enclosed space and allow passage of fluid between the environment and the enclosed space which is detected by the pressure sensor.