Temperature sensors with thermocouples are suitable for the measurement of high temperatures of up to +1,700 °C (3,092 °F). Thermocouples consist of two different metals which are bound together to form the 'thermocouple'. The connection point (hot junction) represents the actual measuring location of the temperature probe, the wire ends are designated as the cold junction. When there is a temperature change at the measuring location, due to the different electron densities of the metals and the temperature difference, a voltage is generated between the hot and cold junctions. This is approximately proportional to the temperature of the measuring location of the temperature probe (Seebeck effect). The low diameter of the of a temperature sensor enables a response time that is faster than is possible with a resistance thermometer.