Humidity indicator cards are mainly distinguished by the number of indicator points, humidity range, color change method (reversible/irreversible), and whether they contain cobalt. They are widely used in moisture monitoring of humidity-sensitive products such as electronic components, precision instruments, and pharmaceutical packaging. Below are the common main model classifications and typical representatives on the market:
Classification by Number of Indicator Points
Three-Point Humidity Indicator Card
Common humidity gradients: 5%/10%/60%, 30%/40%/50%, 5%/10%/15% Suitable for scenarios with specific requirements for critical humidity levels, such as semiconductor packaging (J-STD-033 standard recommends using 5%/10%/60%)
Example Model: 51060HIC125 (Cobalt-free, brown to yellow, conforms to IPC/JEDEC J-STD-033D standard)
Four-Point Humidity Indicator Card
Common humidity gradients: 10%/20%/30%/40% or 20%/30%/40%/50% Provides a finer humidity monitoring range, suitable for industrial packaging with medium precision requirements.
Six-point humidity indicator card
Common humidity gradients: 10%/20%/30%/40%/50%/60% Wide coverage, easy to judge humidity change trends, commonly used in SMT component packaging. Color change logic: Blue when not absorbing moisture, turns pink after absorbing moisture; when the relative humidity is between the color-changing and non-color-changing points, the actual value can be judged by the light purple area in the middle.
Single-point humidity indicator card
Monitors only a specific humidity threshold (e.g., 30%RH or 60%RH). Low cost, suitable for simple scenarios where only the limit needs to be determined.