This humidity indicator card is a useful tool to help protect sensitive items from exposure to too much moisture in the air. It works by taking advantage of the color-changing properties of the chemical cobalt dichloride (CoCl2). When dry, or anhydrous, the CoCl2 circles will appear bright blue. When exposed to moisture, they will gradually turn pink.
• By cleverly creating several circles of various concentrations, a measurement of relative humidity exposure can be determined, rather than a simple yes or no.
• Card can be reset and reused by placing it in a dry container (such as a sealed bag with desiccant or rice) for 24 hours.
1.75" x 4.56"
A humidity indicator card (HIC) is a card on which a moisture-sensitive chemical is impregnated such that it will change color when the indicated relative humidity is exceeded. This has usually been a blotting paper impregnated with cobalt(II) chloride base; Less toxic alternatives include other chemicals such as cobalt-free chloride base and special plastic films.
Humidity indicators are an inexpensive way to indicate or quantify moisture content inside sealed packaging. They are available in many configurations and used in many applications, especially military and semiconductor. The most common humidity indicator cards change color from blue (less than indicated RH level) to pink (greater than indicated RH level).