HR Humidity Indicator cards 20-80%

Made from blotted paper impregnated with a cobalt(II) chloride base at various degrees of concentration, these cards enable to visually monitor whether the humidity levels attained in sealed packaging are acceptable.

As the relative humidity changes in the volume of air surrounding the indicator, the humidity indicator spots will change from blue (dry condition) to violet and eventually pink (humid condition), allowing therefore a clear reading of the sensitivity values. The humidity indicator spots are reversible, and the pink spots will change back to blue when the volume of air is dried.

This product can be stored 2 years.