MS234 Humidity Indicator Card - HUMIDITY INDICATOR CARDS

Description

Representative image: the photograph shows a three-spot humidity indicator card; printed indicator levels vary by model. MS234 indicates 20%, 30% and 40% RH.

MS234 gives a visual check of 20, 30, 40% RH within sealed packaging. Electronics packaging where 20–40% RH checkpoints are required. Used alongside a suitable desiccant, it helps operators inspect the package environment without relying on the appearance of the drying medium alone.

The indicator spots change from blue in dry conditions towards pink as humidity rises. Lavender is the reference colour for reading a marked level. The colour response is reversible: the spots return towards blue as the surrounding air becomes drier, so the card shows current conditions rather than preserving a permanent exposure history.

The standard-card supplier sheet describes a response within eight hours of a humidity change and greatest accuracy at 23°C (73°F). Check that the highest indicator spot is blue before putting a card into service. These checks should be interpreted under the package’s inspection procedure.

Key specifications

• Indicator levels: 20, 30, 40% RH
• Card dimensions: 2 × 3 in
• Behaviour: Reversible
• Pack configuration in supplier sheet: 300 cards per litre can; 7,500 per case

Applications

• Electronics packaging where 20–40% RH checkpoints are required.
• Moisture-sensitive sealed packaging used with an appropriately selected desiccant.

Handling and storage

Store unused cards in their original sealed container with desiccant. Keep cool and dry, away from direct sunlight, water, steam and ammonia. Avoid touching the indicator spots and reseal the supply container promptly after taking out cards.