Which term describes equipment designed to prevent moisture from entering its enclosure under certain conditions?

The term that describes equipment designed to prevent moisture from entering its enclosure under certain conditions is "watertight." This classification indicates that the enclosure is built to withstand the effects of water, especially under conditions where moisture could potentially compromise the functionality or safety of the equipment contained within.

Watertight enclosures are crucial in environments where they may be exposed to heavy rain, splashing water, or even immersion in water. They are tested and rated to ensure that water cannot penetrate through the enclosure, providing a higher level of protection than simply being moisture-resistant.

While moisture-resistant refers to materials that can resist dampness but may not be impervious to water, weatherproof indicates protection against a variety of weather conditions, which may include temperature changes and UV exposure, but does not specifically attest to the enclosure being completely sealed against water. Dust-tight pertains to the prevention of dust ingress, which is another aspect of protection but does not address moisture entry. Thus, "watertight" accurately captures the functionality of the equipment under consideration.