Patent ID: 11951761
Assignee: TEMPTIME CORPORATION
Field: Measurement (Instruments)
Classification: CPC B  G  C | IPC B  G

Claim 21:
22. An environmental exposure indicator, comprising:
a substrate;
an environmental indicator material supported by the substrate being opaque in an initial color state and configured to change its color state to transparent responsive to a predetermined environmental exposure other than light exposure;
a background supported by the substrate and beneath the environmental indicator material and having an apparent color to the naked eye under normal lighting conditions that is the same or similar as the apparent color of the environmental indicator material in its initial color state, so that under normal lighting conditions, the change of color state of the environmental indicator material is not apparent to the naked eye under normal lighting conditions;
a security material supported by the substrate and beneath the environmental indicator material, the security material being either a photochromic material configured to change its color state when exposed to specific light wavelengths or a luminescent material configured to give a bright appearance of a predetermined color when exposed to the specific light wavelengths;
wherein the environmental monitor is selected from the group consisting of a humidity exposure monitor, an oxygen exposure monitor, a freeze monitor, a thaw monitor, a peak heat exposure monitor, a cumulative heat exposure monitor, a current temperature indicator, a pH indicator, and combinations thereof.