Solve the correct identification skills of thermocouple and thermal resistance

What is certain is that both thermocouples and thermal resistances are temperature instruments. If the protective sleeve is completely invisible from the appearance and shape, is there any clever solution? The following editor will sort out the correct identification method of thermocouple and thermal resistance for you. 1. Identifying from the way of outgoing is to look at the outgoing wires of the temperature measuring element. Usually, the thermocouple has only two outgoing wires. If there are three outgoing wires, it is a thermal resistance. However, for those with four lead wires, it is necessary to measure the resistance value to determine whether it is a double thermocouple or a four-wire thermal resistance. First find two pairs of lead wires with almost zero resistance from the four lead wires, and then measure the resistance value between the two pairs of lead wires. If it is infinite, it is a double thermocouple, and the resistance value is almost zero. The lead wire is a thermocouple. If the resistance of the two pairs of lead wires is between 10 and 110, it is a single four-wire thermal resistance. If its resistance value is closest to the thermal resistance of which graduation number, it is the thermal resistance of the graduation number. . If there are only two lead wires, you can use a digital multimeter to measure the resistance value to judge. Since the resistance value of the thermocouple is very small, the thermal resistance is almost zero; if the resistance value is small during measurement, it may be a thermocouple. 2. To identify the thermal resistance from temperature At room temperature, its minimum resistance value will also be greater than 10. Commonly used thermal resistances are Pt10, Pt100 platinum thermal resistance, Cu50, Cu100 copper thermal resistance four grades, at room temperature 20 ℃, the resistance value of Pt10 is 10.779, Pt100 is 107.794, Cu50 is 54.794. 285, Cu100 is 108.571. When the room temperature is higher than 20°C, the resistance value is larger, and it can be judged by comparing the resistance values u200bu200bof the two. If it is a thermal resistance, you can also know what graduation number the thermal resistance is. Third, the soil method can also find an easily available heat source, and judge and identify by heating the temperature measuring element. For example, it can be connected to the hot water of the drinking fountain, put the measuring end of the temperature measuring element into the hot water, and use the DC millivolt block of the digital multimeter to measure whether it has thermoelectric potential. Thermocouple graduation table, you can judge what kind of graduation number the thermocouple is. When there is no thermoelectric potential, measure whether the resistance value has changed. If there is a rising trend of resistance value, it is the thermal resistance. The identification can also be judged by heating the measuring end of the temperature measuring element with an electric soldering iron or an electric oven.