| 摘要 |
PROBLEM TO BE SOLVED: To provide a change management indicator with a simple structure, capable of easily and accurately checking change of temperature, etc. by applying light even in the nighttime or even for a moving body.SOLUTION: A change acceptor 1 changed between an opaque state and a transparent state corresponding to changes of temperature, humidity, wave length, chemical reaction, electric current, magnetic field, time lapse, etc., is formed so as to cover a retroreflective substrate 2. When a change permissible body 1 is liquefied or evaporated by the changes, the liquefied change permissible body 11 prevents retroreflectivity from being damaged by providing a passable transmission hole 3 not to make the liquefied change permissible body 11 remain on a surface of the retroreflective substrate 2. |
