The chemical based time and temperature indicators monitor the product temperature and provide a non-reversible record of temperature exposures. Temperatures above the safe range during transportation and storage will be clearly indicated. They can be used to monitor the cold chain for perishable products; for example food, vaccines, blood and many other applications.
The indicator responds to two different temperatures:
- The first sector on the indicator strip (see picture below) is marked A/B/C and responds to temperatures above +10 °C
- The second sector on the indicator strip (see picture below) is marked D and responds to temperatures above 34 °
Depending on which letter will be colored on the indicator strip, the product can still be used or not.