abstract |
Indicating device suitable for visibly measuring parameters such as time, temperature, and time-temperature relationships. The device includes a porous fluid carrying pad, a wick material for said fluid, and an indicator means whereby the progress of fluid along the wick material can be visibly indicated and used to measure the passage of time, the exposure to a given minimum temperature, or a time-temperature relationship. The combination is adapted to regulate migration of fluid from the fluid source to the wick material. |