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Maintaining the proper environment is essential for preserving the integrity of valuable collectibles, such as the Purple Heart medal. One of the most effective tools for monitoring environmental conditions is the hygrometer, an instrument used to measure humidity levels.
Understanding Humidity and Its Impact on Collectibles
High or fluctuating humidity can cause damage to medals, paper, and other materials. Excess moisture may lead to corrosion, mold growth, or deterioration of the medal’s finish. Conversely, very low humidity can cause materials to become brittle and fragile.
Choosing the Right Hygrometer
There are two main types of hygrometers:
- Mechanical hygrometers: Use a hair or a coil that expands and contracts with humidity changes.
- Digital hygrometers: Use electronic sensors for precise readings and often include additional features like temperature measurement.
For preserving a Purple Heart, a digital hygrometer with a calibration feature and a wide measurement range is recommended for accuracy and ease of use.
Proper Placement of the Hygrometer
Position the hygrometer in the same environment as the medal, ideally within the display or storage case. Avoid placing it near windows, vents, or direct sunlight, which can cause inaccurate readings.
Monitoring and Maintaining Humidity Levels
The ideal relative humidity for preserving medals like the Purple Heart is between 40% and 50%. Regularly check the hygrometer at least once a week to ensure levels remain stable.
If humidity levels are too high, consider using a dehumidifier or silica gel packs to absorb excess moisture. If levels are too low, a humidifier can add necessary moisture to the environment.
Calibrating Your Hygrometer
To ensure accurate readings, calibrate your hygrometer periodically. Many digital models come with calibration instructions, often involving a salt test or using a calibration kit.
Additional Tips for Preservation
- Keep the medal in a stable environment with consistent temperature and humidity.
- Avoid exposing the medal to direct sunlight or fluctuating conditions.
- Store the medal in a display case with controlled humidity if possible.
Using a hygrometer effectively helps preserve the historical and sentimental value of the Purple Heart. Regular monitoring and proper environmental control are key to long-term preservation.