A humidity indicator card is a practical tool that monitors relative humidity in a closed environment through color changes (usually from blue to pink). It is widely used in the moisture-proof packaging of electronic components, optical equipment, pharmaceuticals, and precision instruments. Proper maintenance is crucial to ensure its accuracy and reusability.
Proper Storage
Sealed Storage: Unused humidity indicator cards should always be stored sealed in their original metal cans with a desiccant to prevent premature moisture absorption and deterioration.
Environmental Control: The storage environment should be dry and cool, avoiding direct sunlight or water immersion. The ideal temperature is 15~28℃, and the relative humidity should be ≤60%.
Regular Desiccant Replacement: After opening the metal can more than 3 times, it is recommended to replace the internal desiccant to maintain a low-humidity environment inside the can.
Precautions During Use
Avoid Direct Contact: Do not touch the indicator points with your hands when handling the card, as sweat or oil may affect the accuracy of the color-changing reaction.
Limited Exposure: After removal, place the card back into the test package as soon as possible, avoiding exposure to air for more than 30 seconds to prevent accidental color change.
Reading Timing: Open the sealed package after a period of time to check the color. Compare the reading with the standard color chart to determine the humidity level once the color has stabilized.
Regeneration and Reuse
If the indicator card has changed from blue to pink, regeneration can be achieved through drying: Bake in an oven at 110℃ for 3 hours until the color completely returns to blue.
After cooling to room temperature, immediately return it to the sealed container for storage.
After regeneration, it is recommended to verify its effectiveness in a known dry environment to ensure proper functioning.
