The thermometer have mercury and liquid alcohol, is different by the two kinds of material thermal expansion and contraction for various purposes, under normal circumstances, the heating degree of mercury is produced in the reaction of alcohol than slow, so to measure the body temperature to measure the temperature of alcohol. In a closed space, the characteristics of the thermal expansion of mercury or alcohol will appear to be "volume" increase, no place to go to the space where the pressure. It would be better to think so.
This thermometer with copper - constantan, iron, nickel, aluminum - constantan, cobalt - copper constantan gold, platinum, rhodium etc..
When the working end is placed at the measured temperature, the temperature of the working end and the free end is not the same. A thermometer is a measurement of the amount of electricity that can be used to determine the temperature at the other.
Thermometers are made of thermoelectric phenomena. Two different metal wires are welded together to form a working end, and the other ends are connected with the measuring instrument to form a circuit.
