Temperature sensor type and model selection precautions and instrument wiring precautions - Solutions - Huaqiang Electronic Network

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First, the temperature sensor type and model selection considerations

There are many types and models of sensors. Thermocouples and thermoelectric temperature sensors are commonly used. Thermocouple overflow sensors are commonly divided into S, R, B, K, N, T, E, and J types. Commonly used are divided into Rt100, Pt10, Cu50, Cu100 type. For analog temperature instruments, in general, the table and the temperature sensor are one-to-one correspondence. Therefore, when selecting the instrument, it is necessary to find out which sensor is equipped. If the meter used is inconsistent with the supplied temperature sensor, the meter will not work properly. For the intelligent (internal microprocessor) temperature meter. Because its function is mainly realized by the program, generally it can be used for a variety of tables. With the keyboard setting, it can be equipped with different types and models of temperature sensors.

Second, the instrument wiring precautions

For the thermal resistance overflow sensor, the connection mode with the meter has three-wire system and two-wire system. Since the lead wire resistance is a part of the input resistance and cannot be eliminated due to the two-wire connection method, the accuracy of the temperature measurement is affected, and the lead wire is affected. The longer the impact, the bigger the impact. In the case where the temperature measurement accuracy is high, a three-wire connection method is generally adopted. This type of connection is widely used because it can eliminate the lead resistance, but attention should be paid to the connection of the three wires connected to the meter.

For high temperature measurement conditions (greater than 400 ° C), the temperature sensor of the general instrument is a thermocouple, but the thermocouple temperature sensor is not as accurate as the thermal resistance. It should be noted that the thermocouple must be connected to the compensation wire, and its model must be consistent with the temperature sensor. For the temperature meter with the sensor as thermocouple, pay attention to the temperature compensator. The temperature compensation mode is divided into internal compensation and external compensation. There are also various compensation circuits. Pay attention to the use.