Thermal resistance definition
Thermal resistor refers to an electronic component whose resistance value changes with temperature change within a certain temperature range. Normally, the resistance value of a thermal resistor increases as the temperature increases, or decreases as the temperature decreases. This relationship can be expressed by the temperature characteristic curve of the thermal resistor. Thermal resistance is mainly affected by factors such as the temperature coefficient and geometric structure of the material. Common thermal resistors include platinum resistors, nickel resistors, copper resistors, etc. Among them, platinum resistors have higher accuracy and better stability, and are widely used in the field of temperature measurement.
Thermal resistance classification
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Metal thermal resistor
Such as platinum resistance, nickel resistance, copper resistance, etc., which utilize the characteristics of metal resistance that changes with temperature.
- Semiconductor thermal resistance
Mainly made of semiconductor materials, such as silicon, germanium, tellurium and other elements, it has good sensitivity and response speed, and can also work in high temperature environments.
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Carbon film thermal resistor
The thin film formed by combining metals such as chromium and nickel with graphite has the advantages of small size, light weight and fast response speed.
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Platinum-Rhodium Thermocouple
Composed of two metals, platinum and rhodium, it is widely used in the field of temperature measurement because of its high stability and accuracy.
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ferrite thermocouple
It is composed of ferrite and doping elements (such as molybdenum, cobalt, etc.) and is mainly used for temperature measurement in high temperature environments.
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Magnetostrictive thermal resistance
Made of magnetic materials such as iron and nickel, temperature measurement is achieved through the coupling effect of magnetization and strain.
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Thermal resistance tape
By adding impurities or changing the structure of the crystal to improve its thermoelectric properties, a highly sensitive thermal resistance element can be obtained.
Advantages of thermal resistance
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High precision
Since there is a relatively linear relationship between the characteristics of thermal resistors and temperature, their measurement accuracy is high.
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good stability
Because thermal resistors are not easily affected by mechanical, chemical and other environmental factors, they have a long service life and good stability.
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quick response
Compared with other temperature measurement elements (such as thermocouples), thermal resistors have a faster response speed and can achieve more timely temperature detection.
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High reliability
Because the thermal resistor has high sensitivity and accuracy and can work stably in various complex environments, its reliability is higher.
Disadvantages of thermal resistance
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expensive
Compared with other temperature measurement components, such as thermocouples, thermoelectric deviation meters, etc., the cost of thermal resistors is higher.
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Low sensitivity
Although thermal resistors have high accuracy, their sensitivity is relatively low, and small temperature changes may cause measurement errors.
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Complex structure
The manufacturing and use of thermal resistors require precise processing technology and detection methods, which are relatively complex.
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subject to temperature restrictions
Since different types of thermal resistors have different operating temperature ranges, their applications are subject to certain temperature restrictions.
Development history of thermal resistance
In 1821, the German physicist Seebeck discovered that when two different metals are connected to form a closed circuit, a potential difference will be generated under the influence of temperature difference, that is, the thermoelectric effect. In 1833, another German physicist Constantine discovered that when the direction of the current passing between two different metals is reversed, the endothermic and exothermic phenomena will also change accordingly, which is the Constantine effect. In 1871, British physicist Paul Ballinger first proposed using platinum resistance to measure temperature.
In 1887, French physicist Julien applied platinum resistors to industrial thermometers. In 1901, the American Edmonson proposed a method of using platinum-rhodium thermocouples to achieve high-precision temperature measurement. In the 1930s, thermal resistors gradually became widely used in the field of industrial temperature measurement due to their advantages such as good stability and wide linear range. In 1948, the international standard unit of thermal resistance PT100 was officially determined. PT100 is a thermal resistance element made of platinum. It has stable performance and high accuracy and is widely used in the field of temperature measurement. After the 1980s, with the continuous advancement of materials science and technology and microelectronics technology, new thermoelectric materials and thermal resistance sensors have continued to emerge, such as carbon nanotube thermal resistors, semiconductor thermal resistors, etc., which have promoted the continuous development and innovation of thermal resistance technology.
Thermal resistance upstream, middle and downstream
The upstream is thermal resistance materials and preparation. It mainly includes manufacturers of platinum, nickel, copper and other metal materials and semiconductor materials, as well as related preparation technology research institutions. The midstream is the production and testing of thermal resistance components. It mainly involves the processing, manufacturing, assembly and testing of thermal resistance components. The main participants in this link include sensor manufacturers and measuring instrument manufacturers. The downstream mainly includes industries that require high temperature measurement accuracy in aerospace, electric power, medicine, chemical industry and other fields. In addition, with the development of Internet of Things, smart home and other technologies, thermal resistors also have broad application prospects in the intelligent field.
Data source: Zhiyanzhan Industry Research Institute
Thermal resistance market size
In 2017, domestic thermal resistance market size was approximately RMB 5 billion, a year-on-year increase of approximately 10%. In 2018, my country's thermal resistance market size was approximately RMB 5.5 billion, a year-on-year increase of approximately 10%. In 2019, due to the increasing uncertainty of the global economic situation and the impact of Sino-US trade friction and other factors, the growth of my country's thermal resistance market slowed down slightly, with the market size being approximately 5.7 billion yuan, a year-on-year increase of approximately 5%. In 2020, due to the shrinkage of the global economy caused by the new crown epidemic and the certain impact on the domestic industrial chain, the growth rate of my country's thermal resistance market has declined. The market size is approximately 5.9 billion yuan, a year-on-year increase of approximately 3.5%.
Statistics show that the market size of China's thermal resistance industry was 5 billion yuan in 2017, and the market size of China's thermal resistance industry will be 6.8 billion yuan in 2022. The market size of China's thermal resistance industry from 2017 to 2022 is as follows:
Market size of China's thermal resistance industry from 2017 to 2022
According to predictions, the market size of China's thermal resistance industry will be 23.5 billion yuan in 2029.
Forecast of market size of China’s thermal resistance industry from 2023 to 2029
It is expected that the global thermistor market size will reach US$4.42 billion by 2025, showing a continued growth trend. In the Chinese sensor market, temperature sensors (including thermocouples and thermal resistors) account for the largest proportion, and market demand continues to increase. There are many participants in the thermal resistance industry, mainly including Shanghai Costar, Jiangsu Chint Instrument, Tianjin Jincheng Thermoelectric, Hailar Technology, etc.
Thermal resistance development policy
"Made in China 2025" puts forward the goal of strengthening the industrialization and intelligent development of new sensors, encourages enterprises to increase technology, product and market innovation, and promotes technological upgrading and industrial transformation in the field of sensors such as thermal resistors. The National Development and Reform Commission and the Ministry of Industry and Information Technology jointly issued the "Guiding Opinions on Promoting High-Quality Development of the Sensor Industry" in 2016, proposing to support sensor research institutions and enterprises to carry out basic research and application development, and strengthen the construction of the industry standard system. The "China Electronic Information Industry Development Plan (2016-2020)" proposes to accelerate the independent, controllable and industrialized development of key components such as integrated circuits and sensors, and promote the technological innovation and application promotion of sensors such as thermal resistors.
Detailed analysis of the development obstacles of thermal resistance
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Technical bottleneck
Although thermal resistance technology is relatively mature, there are still some technical bottlenecks, such as temperature range, accuracy and stability, and there is still room for improvement.
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Lack of industry standards
Since the production standards and specifications of thermal resistance products have not been uniformly formulated, there are products of uneven quality on the market, which has affected the development of the entire industry.
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High-end market is restricted
The domestic high-end market has a large demand for thermal resistance products, but domestic companies have a low market share in the high-end market, which makes some high-end markets monopolized by foreign brands.
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cost pressure
As raw material prices and labor costs rise, the production costs of thermal resistance products are also gradually increasing, which is a challenge for enterprises in the thermal resistance industry.
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Competition is fierce
Currently, there are many participants in China's thermal resistance industry, and the market competition is fierce. In this case, companies need to continuously strengthen their technological innovation and product quality to maintain their competitiveness in the market.
Data source: Zhiyanzhan Industry Research Institute
Detailed analysis of thermal resistance development space
As various industries have higher and higher requirements for temperature measurement accuracy and stability, the application fields of thermal resistors will continue to expand, such as electric power, chemical industry, medicine, food and other fields that require the use of thermal resistors for temperature measurement. Although thermal resistance technology is relatively mature, with the improvement of technology and the application of new materials, the temperature range, accuracy and stability of thermal resistance products will continue to improve, thus broadening the application scope of thermal resistance.
With the development of technologies such as the Internet of Things, smart manufacturing, and smart homes, the demand for intelligent sensors such as thermal resistors is also increasing. This will drive the transformation of the thermal resistance industry towards intelligence and automation, bringing more business opportunities to enterprises. With the continuous expansion of the domestic market and consumption upgrading, the sales of sensor products such as thermal resistors are also increasing year by year. It is expected that the scale of China's thermal resistance market will continue to maintain a high growth rate in the next few years.
In recent years, some innovative companies have emerged in the thermal resistance industry. These companies continue to strengthen their technological innovation and product quality, actively expand domestic and foreign markets, and have achieved obvious market advantages in some fields. Generally speaking, the thermal resistance industry has broad development space and market prospects, especially in terms of expansion of application fields, increased demand for intelligence, and domestic market potential. There are a lot of business opportunities and development space.
