What is the effect of humidity dropping below 40% on radiographic films?

When humidity levels drop below 40%, radiographic films can experience an increase in static marks. This is primarily due to the lack of moisture in the air, which can lead to the buildup of static electricity on the film surface. Static electricity can cause patterns of discharge that appear as marks or artifacts on the film once it is exposed and processed.

In lower humidity conditions, the emulsion on the film does not absorb enough moisture, making it more susceptible to the accumulation of static charges. These static marks can be particularly problematic in imaging processes, as they can obscure or distort the necessary details meant to be captured.

Maintaining proper humidity levels is crucial for the optimal preservation and quality of radiographic films, as it helps to mitigate the risks of static and ensures clear imaging results.