Surface thermometer is bimetallic thermometer?

On the surface of the working principle of the thermometer is based on the principle of solid heat expansion, the two pieces of expansion coefficient difference is very big pieces of metal welded together. When the temperature changes, the difference is very big, caused the different expansion coefficient of expansion and contraction, the deformation of sheet metal bending. According to different deformation and produce different momentum, momentum to drive the connection shaft and the other end of the indicating needle, indicate the temperature. Thus, the surface thermometer is bimetallic thermometer. The thermometer on the surface of the adsorption on the surface of the measured medium that clean, reaction time, wait for 15 minutes this time as the temperature dial indicator on the surface of the measured medium temperature. Using surface temperature time must mainly two things: 1. Before use must be wiped clean surface of the magnet of the thermometer and the surface of the measured medium, otherwise, will affect the thermal conductivity; 2. Began to use, be sure to wait for about 15 minutes, otherwise the surface thermometer readings is not stable.