While the Temperature Power Sensor appears to have a sealed structure, is it a waterproof type?
Unfortunately, it is not waterproof.
This level of structure is normally called a dustproof or drip-proof structure.
While it can be immersed in water for a few hours, longer immersion is not recommended.
For a short time immersion waterproof capability, a double shield(DS) type is recommended, and for a complete waterproof capability, a thermostat for liquid temperature control is recommended.