How to distinguish between thermal resistance and thermocouple

Thermocouple and thermal resistance are contact temperature measurement of temperature measurement, although the effect is same measurement temperature of the object, but the principle and characteristics of them is different.

the thermocouple is industry one of the most commonly used temperature detecting element, the working principle of the thermocouple are two different components of conductor ends connected into a circuit, such as two different connection end temperature, then to produce thermoelectric potential physical phenomena in the loop. Its advantage is: high precision measurement. Because of thermocouple direct contact with the object being measured, not affected by intermediate medium. Wide measuring range. The commonly used thermocouple from - 50 ~ + 1600 ℃ can renew edge measurement, some special thermocouple minimum measurable to - 269℃（ Such as gold iron nickel chrome) , up to + 2800 ℃ ( Such as tungsten - Rhenium) 。 Simple structure, easy to use. Thermocouple is usually composed of two different kinds of metal wire, but is not limited by the size and the beginning of, outside has protective casing, which are very convenient.

basic principle of thermocouple temperature measurement: the two different material A conductor or semi-conductor A and B welding together, form A closed loop. When the conductor A and B two persistent point temperature difference between 1 and 2, occurs between the electromotive force, thus forming the size of A current in the circuit, this kind of phenomenon called the thermoelectric effect. Thermocouple is in using this effect to work.

the commonly used thermocouple can be divided into two categories, thermocouple and non standard thermocouples. Invokes standard thermocouple is refers to the national standard specifies its thermoelectric potential and the relationship between temperature, permissible error, and a unified standard score table of thermocouple, it has with matching display instrument to choose from. Non-standard thermocouple or on the order of magnitude less than the range using standardized thermocouple, generally no unified indexing table, mainly used for the measurement of some special occasions. Commonly used thermocouple are k type thermocouple and armoured thermocouple, platinum rhodium thermocouple

low temperature zone of the most commonly used in thermal resistance is a kind of temperature detector. Its main characteristic is high accuracy, stable performance. Among them is platinum thermal resistance measurement accuracy is the highest, it is not only widely used in industrial temperature measurement, and is made into standard benchmark instrument. Thermal resistance temperature measurement is based on the metal conductor resistance value increases with the increase of the temperature of the properties for temperature measurement. Heat resistance is mostly made of pure metal materials, the application at present most is platinum and copper, in addition, now have begun to use the materials such as nickel, manganese and rhodium manufacturing thermal resistance. Thermal resistance can be divided into: flameproof thermal resistance, normal thermal resistance, armored thermal resistance, transverse thermal resistance.