The present invention provides a method for determining whether or not moisture
appeared in a hidden place during a period T, the method comprising: (i) introducing
to the hidden place a moisture sensitive element; the moisture sensitive element
comprising: a) a dielectric substrate coated or impregnated with an intrinsically
conducting polymer and b) probes connecting the substrate to a resistance meter;
(ii) measuring and recording the electrical resistance of the substrate at two
or more times during the period T; (iii) determining whether or not moisture appeared
in the hidden place during the period T according to the changes in the electrical
resistance of the moisture sensitive element that occurred during period T. The
present invention further provides method and system for alerting against a possible
appearance of corrosion in a hidden place, a moisture sensor for use in the method
or system, and a method for producing a substrate comprised in such a moisture sensor.
