End thermocouple temperature sensing element resistance wire winding by special processing, close to the face in the thermometer. Compared with axial usually thermocouple, it can more correctly and quickly reflect the actual temperature of end face, is suitable for measuring bearing and other parts of the end surface temperature. According to measuring temperature range: 500 ℃ or more usually choose thermocouple, usually choose thermocouple below 500 ℃; According to measurement accuracy, high requirements for accuracy thermocouple, requirements for accuracy is not high choose thermocouple; According to measuring range: measured by thermocouple temperature usually refers to the 'point', the average temperature measured by thermocouple is usually refers to the space; 2 wire thermocouple wiring simple, but to bring in additional error lead resistance. Therefore shall not apply to the manufacturing accuracy of grade A thermocouple, and in the use of wire and wire shoulds not be too long. Wire system can eliminate the influence of the lead resistance, measurement accuracy is higher than 2 wire system. As the process of detecting element, its application is very wide. Wire system not only can eliminate the influence of the lead resistance, and the connection wire resistance phase at the same time, also can eliminate the influence of the resistance. When in the high accurate measurement, must use the four wire system.