How Reversible Temperature Labels Work
Understanding the science behind liquid crystal thermochromic technology and how to interpret the results.
As implied in the name, reversible temperature labels can change color back and forth as needed in order to display the current temperature to which they are exposed. One major advantage of reversible labels is that they can be used multiple times.
Since they are constantly changing depending on the temperature they are in, monitoring must be done at the time of the event. They will not record temperature changes from the past, only display the current temperature.
The "Spiral Staircase" Effect
Reversible labels use special molecules called cholesteric liquid crystals. Instead of a complex chemistry lesson, think of these molecules like a microscopic spiral staircase.
The Cold State: When cold, the staircase is tightly coiled. It absorbs light, making the label appear black.
Heating Up: As the temperature rises, the heat causes the "staircase" to twist, stretch, and expand.
Reflecting Light: This twisting changes how light bounces off the molecules. Depending on exactly how stretched the staircase is, it reflects different colors of the visible light spectrum:
- • First, it reflects Red (lower end of the temperature range).
- • As it twists further, it reflects Green (the middle/actual target temperature).
- • With more heat, it reflects Blue (the higher end of the range).
Cooling Down: Because the process is reversible, when the temperature drops, the staircase coils back up, and the colors reverse in order.
- Temperature Range-30°C to 120°C (-22°F to 248°F)
- Accuracy Tiers
• ± 1°C (Range: -30°C ~ 59°C)
• ± 2°C (Range: 60°C ~ 89°C)
• ± 3°C (Range: 90°C ~ 120°C)
- Shelf Life18 - 24 months (under recommended storage conditions)