How the temperature sensor works

There are several different ways of measuring temperature. From simple diodes to high-precision noise thermometers. In the laboratory, the most important thing is the thermometer that does not need to be calibrated by other thermometers. In industry, secondary thermometers are mainly used to measure temperature, and these sensors need to be calibrated. In practice, the most commonly used are resistance thermometers or thermocouple thermometers. There are several different ways to meet process control temperature measurement. From simple diodes to high-precision noise thermometers. In the laboratory, the most important thing is the thermometer that does not need to be calibrated by other thermometers. In industry, secondary thermometers are mainly used to measure temperature, and these sensors need to be calibrated. In practice, the most commonly used are resistance thermometers or thermocouple thermometers. In order to meet the needs of process control measurement signal accuracy, the following sensors have become the standard: 　　 resistance thermometer detects temperature through resistance value. Pure metals have the greatest impedance change, especially very pure precious metals. The resistance value of the positive temperature coefficient thermistor increases with the rise of temperature, while the negative temperature coefficient thermistor is just the opposite. If the resistance and temperature show a linear relationship, the temperature value can be calculated by a polynomial. Generally, the measurement range of a resistance thermometer is -250 to 1000 degrees Celsius. Such sensors include standardized sensors made of platinum (for example: P t 100, 100 Ω at 0 ℃). In high-precision measurement, they can be applied to a variety of working conditions up to 850 ℃. Although the thermocouple is not as accurate as the thermal resistance, it has a faster response speed.　　Thermocouple sensor is composed of two different metals or semiconductors connected to each other. When there is a temperature difference between the two metals, a pressure drop will occur at the junction. This phenomenon is also called the Seebeck effect. The thermal voltage of metal (also called thermoelectric energy) is related to temperature, and generates a few microvolts per Kelvin. In fact, this measurement principle is to measure the temperature difference between the hot end and the cold end. If you want to determine the temperature of the hot end, you must know the temperature of the cold end. vice versa. In practice, people usually use other temperature sensors to measure the temperature of the cold junction. The temperature of the hot end (measurement point) can be pushed down by the thermal voltage. Thermocouple sensors are usually used to measure temperatures exceeding 1000°C. Its accuracy depends on the precise measurement of the temperature at the junction.　　Variable Turck scheme　　The biggest challenge of temperature measurement is that it is often difficult for operators to reach the best detection point. This is why there are special requirements such as highly flexible process connections and easy-to-observe sensor readouts. In recent years, Turck has introduced an intelligent temperature detection program. Turck's P t100 temperature sensor has a high E M C level and an IP 67 protection level. It is an all-stainless steel structure and metal electrical connectors that provide high mechanical stability and operational safety. When using temperature sensors, users can choose probes of different lengths and diameters. In addition, through the protective sleeve, the temperature sensor can adapt to very harsh environments. Flexible connection and rigid connection are optional, and a variety of outputs are optional. Turck provides customers with the most flexible temperature products.