Precautions while using Laboratory Thermometers
Points to kept in Mind while using a thermometer
The thermometer should be protected from sudden changes of temperature. Never wash a hot thermometer in cold water or put a cold thermometer in a hot bath. For correct reading of temperature see that the thermometer is vertically and your eyes are exactly in line with the mercury level. Mercury on heating expands. Even a small expansion of mercury in the bulb of the thermometer causes a considerable rise in the capillary tube.