For the temperature sensor or humidity sensor, we will certainly not feel strange, but the temperature and humidity sensor must be strange! Temperature and humidity sensors are used in some places where books and archives are kept and where temperature and humidity need to be kept constant. Among them, Siemens is a very good brand of temperature and humidity sensors.
Siemens temperature and humidity sensor is an ideal solution for environmental applications such as library, archives, production workshop, industrial automation, HVAC, pharmaceutical and chemical industry, communication room, environmental monitoring, clean workshop, intelligent building, telecommunications base station, etc; This temperature sensor selects high-quality integrated digital temperature and humidity sensor as the probe, which ensures the excellent long-term stability, low hysteresis and strong anti chemical pollution ability of the sensor. This sensor also has excellent repeatability, convenient use, convenient maintenance, no calibration, rapid replacement and low cost.
Thermocouple: thermocouple is the most commonly used temperature sensor in temperature measurement. Its main advantage is that it has a wide temperature range and can adapt to various atmospheric environments. It is solid, low price, no power supply and the cheapest. The thermocouple consists of two different metal wires (metal A and metal b) connected at one end. When one end of the thermocouple is heated, there is a potential difference in the thermocouple circuit. The measured potential difference can be used to calculate the temperature. However, there is a nonlinear relationship between voltage and temperature. Due to the nonlinear relationship between voltage and temperature, it is necessary to make a second measurement for the reference temperature (Tref), and use the software or hardware of the test equipment to process the voltage temperature transformation in the instrument to finally obtain the thermocouple temperature (TX). Agilent 34970A and 34980A data collectors have built-in measurement and operation capabilities. In short, thermocouple is the simplest and most common temperature sensor, but thermocouple is not suitable for high-precision measurement and application.
Thermistor: thermistor is made of semiconductor materials, mostly with negative temperature coefficient, that is, the resistance decreases with the increase of temperature. Temperature change will cause large resistance change, so it is the most sensitive temperature sensor. However, the linearity of thermistor is very poor, and it is closely related to the production process. The manufacturer cannot give a standardized thermistor curve. Thermistors are very small and respond quickly to temperature changes. However, thermistor needs current source, and its small size also makes it very sensitive to self heating error. The thermistor measures the absolute temperature on the two lines, which has good accuracy, but it is more expensive than the thermocouple, and the measurable temperature range is also smaller than the thermocouple. The resistance value of a common thermistor at 25 ℃ is 5K Ω, and the resistance change of 200 Ω is caused by the temperature change of 1 ℃. Note that the lead resistance of 10 Ω only causes a negligible error of 0.05 ℃. It is well suited for current control applications that require fast and sensitive temperature measurements. Small size is advantageous for applications with space requirements, but care must be taken to prevent self heating errors.
The above is a brief introduction and selection method of Siemens temperature and humidity sensor. I hope you can refer to it. If we need to buy and use temperature and humidity sensor in the future, we can buy it through the above methods. Siemens temperature and humidity sensor is a very good brand.