HemoTemp® II indicators are reversible/irreversible liquid crystal blood bag temperature indicators which offer the time and temperature history of the blood unit. After activation, the irreversible portion will change color from blue to a non-blue color as the blood temperature increases and as time passes. Once the indicator has lost its blue color, it will not return to its original color even if the blood unit is re-cooled. This ensures the user of the time and temperature history of the unit.
The color of the activated indicator is dependent on product temperature, the time at that temperature, the size or mass of the sample, and the heat transfer characteristics of the sample container. Because the color change of HemoTemp II indicators is affected by the same variables that affect the time/temperature sensitive blood bag, these indicators will monitor the temperature history.
The reversible portion of the indicator provides a continuous temperature monitoring, allowing for an easy to read check of the current temperature of the blood between 1°C and 9°C.