Method and sensor for detecting thermal history

摘要

Disclosed herein is a method and sensor for easily detecting the thermal history (or the change in state by heat) of a specimen. The sensor is made up of a pair of electrodes 1, 1, a diffusion layer 2 of insulating material disposed between the electrodes, and an electrically conductive metal 3. The electrodes are electrically isolated from each other in the beginning. As the sensor experiences heat history, the electrically conductive metal diffuses into the diffusion layer 2, thereby changing the resistance of the diffusion layer. When in use, the sensor is placed in or near the atmosphere to which the specimen is exposed. In response to the change of the specimen by heat, the electrically conductive metal 3 diffuses into the diffusion layer 2 to such an extent that the electrical resistance across the electrodes extremely decreases after a certain period of time. Thus it is possible to detect the deterioration or life of the specimen by monitoring the change in electrical resistance of the sensor.