摘要:
A new and improved apparatus for detecting cracks in the heat-insulating liner of a container for cold liquids, wherein a plurality of breakable or frangible electrical conductors and a barrier means having a woven mat of glass-fiber material are incorporated in the heat-insulating material and detector means is connected with the electrical conductors to detect breaks in the electrical conductors caused by cracks in the heat-insulating material attaining a critical length. The frangible electrical conductors may be frangible wires or stripes of conducting paint.