Some models of thermal resistance and thermocouples are very similar. Many people think that thermal resistances and thermocouples are the same kind of thing. In fact, they are not. Let's take a look at the difference between thermal resistances and thermocouples, and how to distinguish between thermal resistance and Thermocouple method.
1. What is thermal resistance?
Thermal resistance is the most commonly used type of temperature measuring element in low and medium temperature areas. The temperature measurement principle of thermal resistance is based on the characteristic that the resistance value of a conductor or semiconductor changes with temperature to measure temperature and temperature-related parameters. Thermal resistance usually needs to pass the resistance signal to the computer control device or other secondary instrument through the lead.
What is a thermocouple?
Thermocouple is a commonly used temperature measuring element in temperature measuring instruments. It directly measures the temperature and converts the temperature signal into a thermoelectromotive force signal. It is converted into the temperature of the measured medium through an electrical instrument (secondary instrument).
Difference between thermal resistance and thermocouple
Although thermocouples and thermal resistors are both used as temperature sensing elements, their principles and functions are different. The difference between thermal resistors and thermocouples is that their temperature measurement principles are different.
Thermal resistance is a temperature measurement based on the thermal effect of resistance, that is, the characteristic that the resistance of the resistor changes with temperature. Therefore, as long as the resistance change of the temperature-sensing thermal resistance is measured, the temperature can be measured.
Thermocouples measure the temperature directly, and convert the temperature signal into a thermoelectromotive force signal, which is converted into the temperature of the measured medium through an electrical instrument (secondary instrument).
Since the thermal resistance and the thermocouple are so similar, how do you distinguish between a thermal resistance and a thermocouple? Let's talk about the 3 most practical ways to distinguish between thermal resistance and thermocouple.
Method 1: Determine whether it is a thermocouple or a thermal resistor according to the nameplate. The nameplate will contain the specific product and specification information of the thermocouple or the thermal resistor. We can distinguish whether it is a thermocouple or a thermal resistor by carefully observing and distinguishing.
Method 2: According to the structure, distinguish between a thermocouple and a thermal resistor. A thermocouple is generally composed of a thermal electrode, an insulation tube, a protective sleeve, and a junction box. The thermal resistance is that the load and power output by the sensor are connected in series.
Method 3: Use the terminal block to determine whether there is a positive or negative electrode to distinguish a thermocouple, and a positive electrode or negative electrode to distinguish a thermal resistor. This method of differentiation is relatively simple, you can try it.
Finally, thermocouples and thermal resistors are two different components. This is the biggest difference between thermocouples and thermal resistors. Don't confuse them.