HUMIDITY SENSOR AND METHOD FOR PREPARING A HUMIDITY SENSOR

摘要

The invention relates to a humidity sensor of electric resistance type whose electric resistance changes in accordance with an ambient humidity, characterized by a protective film of silicone resin provided on the surface of a humidity-sensitive material, and to a method for preparing the same. The protective film of silicone resin is formed by applying a varnish of siloxanes to the humidity-sensitive material and subjecting the varnish to reaction. The varnish can be of one-part curing system or two-part curing system, and desirably the reaction of siloxanes is a cross-linking reaction. The formed protective film is not influenced by swelling or shrinking of the humidity-sensitive material, and is prevented from flowing off due to a temperature rise, or from deposition of dusts, etc.