1、 What is a single headed tube
A single headed tube is one of the most commonly used temperature detection components in industry. The working principle of a single headed tube is based on the Seeback effect, which means that two conductors with different compositions are connected at both ends to form a circuit. If the temperature of the two connecting ends is different, a physical phenomenon of thermal current is generated in the circuit.
2、 Basic principle of single head tube temperature measurement
Based on the functional relationship between thermoelectric electromotive force and temperature, a single headed tube indexing table is made; The graduation table is achieved under the condition of a free end temperature of 0 ℃, and different single headed tubes have different graduation tables.
A single headed tube is a temperature sensing element that is a primary instrument that directly measures temperature and converts the temperature signal into a thermoelectric electromotive force signal, which is then converted into the temperature of the measured medium through an electrical instrument (secondary instrument).
The basic principle of single headed tube temperature measurement is to form a closed circuit with two different materials of conductors. When there is a temperature gradient at both ends, there will be overcurrent in the circuit, and there will be an electromotive force between the two ends - thermoelectric electromotive force, which is called the Seebeck effect.
When a third metal material is connected to a single headed tube circuit, as long as the temperature of the two contacts of the material is the same, the thermoelectric potential generated by the single headed tube will remain unchanged, that is, not affected by the connection of the third metal to the circuit. Therefore, when measuring temperature with a single tube, a survey instrument can be connected to measure the thermoelectric force, and the temperature of the measured medium can be known. Two homogeneous conductors with different compositions are thermoelectric electrodes, with the higher end being the office end and the lower end being the free end. The free end is usually at a constant temperature.
When there is a temperature difference between the two attachment points 1 and 2 of conductors A and B, an electromotive force is generated between the two, resulting in a current of varying magnitude in the circuit. This phenomenon is called the thermoelectric effect. Single headed tubes work by utilizing this effect.

Two conductors with different compositions (called single ended tube wires or thermoelectric electrodes) are connected at both ends to form a circuit. When the temperature at the junction is different, an electromotive force is generated in the circuit, which is called the thermoelectric effect, and this electromotive force is called the thermoelectric potential. The single headed tube is used for temperature measurement based on this principle. One end directly used for measuring the temperature of the medium is called the working end (also known as the measurement end), and the other end is called the cold end (also known as the compensation end); The cold end is connected to the display instrument or supporting instrument, and the display instrument will indicate the thermoelectric potential generated by the single headed tube.

A single headed tube is actually an energy converter that converts thermal energy into electrical energy, and uses the generated thermoelectric potential to measure temperature. For the thermoelectric potential of a single headed tube, the following issues should be noted:
1. The volume of thermoelectric potential generated by a single headed tube, when the material of the single headed tube is average, is independent of the length and diameter of the single headed tube, but only related to the composition of the single headed tube material and the temperature difference at both ends.
2. The thermoelectric potential of a single headed tube is the difference in temperature function between the two ends of the tube, rather than a function of temperature difference between the two ends of the tube.
3. After confirming the material composition of the two single headed tube wires, the volume of the single headed tube thermoelectric potential is only related to the temperature difference of the single headed tube; If the temperature at the cold end of a single headed tube remains constant, the thermoelectric potential entering the single headed tube is only a single value function of the temperature at the office end.
Foshan Feiyue Electric Heating Technology Co., Ltd. was founded in 1993 and is a modern Sino foreign cooperative company specializing in the production of electric heating components. Our company has always been highly praised and trusted by customers for its high-quality single head pipes and excellent after-sales service. With the continuous development of our business, our products have been sold nationwide and even overseas.