Humidity indicator cards are essential tools for monitoring humidity levels within sealed packaging. They are widely used in moisture-sensitive products such as electronic components, precision instruments, and pharmaceuticals. Correct use effectively determines the sealing of the packaging and whether the desiccant has expired.
Preparation Before Use
Check Appearance and Expiry Date
Ensure the humidity indicator card is undamaged, dry, or discolored, and that the production date is within the expiry date. Avoid using cards that have been exposed to high humidity environments beforehand.
Avoid Direct Contact
Wear clean gloves during operation. Do not touch the indicator points directly with your hands, as the temperature and humidity of your hands can affect the accuracy of the color change.
Storage Guidelines
Unused cards should be stored in their original sealed tin can with desiccant. Replace the desiccant after three openings. Store in a cool, dry place, away from direct sunlight and water immersion.
Installation and Sealing
Proper Placement
Place the humidity indicator card in a moisture-proof bag (MBB) or sealed container, typically next to the product but not in direct contact with metal parts to prevent contamination or short circuit risks.
Use with desiccant
The humidity indicator card must be sealed together with the desiccant (such as silica gel or molecular sieve) to indirectly reflect the desiccant's moisture absorption effect. If the card has turned pink when the packaging is opened, it indicates that the internal humidity is too high, and the desiccant may be saturated.
Secondary sealing operation
In packaging such as hexahedral rust-proof bags, the humidity indicator card can be inserted along the middle of the sealing edge before heat sealing to ensure airtightness.