What is an acceptable damp reading?
Damp readings for archives are a measure of the moisture content of the air within a storage space. The ideal relative humidity (RH) level for archives is between 30% and 50%. A damp reading outside of this range can cause damage to archival materials.
How to measure damp readings
Damp readings can be measured using a hygrometer. Hygrometers are available in both analog and digital formats. To ensure an accurate reading, the hygrometer should be placed in the center of the storage space, away from any heat sources or vents.
What to do if the damp reading is too high
If the damp reading is too high, there are a number of steps that can be taken to reduce the moisture content of the air. One option is to use a dehumidifier. Dehumidifiers are available in a variety of sizes and capacities. Another option is to increase the temperature of the storage space. This will cause the air to hold more moisture, thereby reducing the relative humidity.
What to do if the damp reading is too low
If the damp reading is too low, there are a number of steps that can be taken to increase the moisture content of the air. One option is to use a humidifier. Humidifiers are available in a variety of sizes and capacities. Another option is to decrease the temperature of the storage space. This will cause the air to hold less moisture, thereby increasing the relative humidity.
Conclusion
Damp readings are an important part of preserving archival materials. By ensuring that the damp reading is within an acceptable range, you can help to prevent damage to your valuable collections.