Water dipping thermometers with housing

The water dipping thermometer is used to measure water temperatures in surface waters. It consists of a metal housing (nickel-plated brass) in which a mercury thermometer is located. The mode of operation is based on the fact that the measuring chamber fills with water at the measuring depth, and thus the thermometer vessel assumes the water temperature. When the thermometer is pulled to the surface, the water remaining in the measuring chamber maintains the water temperature at the measuring point.