摘要 |
The light dose received by perishable goods is an important parameter in determining the of those goods. A light sensor (30) is described having a photosensitive element (18) which changes its material property according to the light dose received. This change can be detected electrically by electrodes (12, 14) in the light sensor. Because the change in material property is permanent, this removes the need for a memory to store a value representing the light dose received by the light sensor. |