Common causes of thermal resistance and their solutions

From the principles of thermal resistance and the problems of daily application, you can learn more about the performance and use of thermal resistance. Below by our technical staff to explain: Thermistor temperature measurement principle.

a, thermal resistance temperature measurement system is generally composed of thermal resistance, connecting wires and display instruments. The index number of the thermal resistance and the display instrument must be the same. In order to eliminate the influence of the resistance change of the connecting wire on the temperature measurement, a three-wire connection method must be used.

b. The thermal resistance is based on the characteristic that the resistance value of the metal increases as the temperature increases. The most commonly used is made of platinum and copper metal, with a graduation number of Pt50 (temperature range -200 ~ 850 °C), Pt100, Pt10, Cu50, Cu100 (temperature range of -50 ~ 150 °C).

c. Common causes and treatment methods of thermal resistance Common faults of thermal resistance are thermal resistance open circuit and short circuit. General disconnection is more common because of the finer thermal resistance wires. Open circuit and short circuit are easy to judge, you can use the multimeter's "×1Ω" file. If the measured resistance is less than R0, there may be a short circuit; if the multimeter indicates infinity, you can determine that the resistor is open circuit. Resistor short-circuit is generally easier to handle, as long as it does not affect the length and thickness of the resistance wire, find the short-circuit where to dry, strengthen the insulation. Resistor body circuit repair must change the length of the resistance wire and affect the resistance value. For this reason, it is better to replace the new resistor body. If soldering repair is used, it must be verified after passing the welding. About the thermal resistance temperature measurement system in the operation of common faults and treatment methods are as follows:

Symptom Possible Causes Remedy Indication Instrument indication Infinity Thermal resistance or lead wire disconnection and loose contact terminals Replace the resistor body, or solder and tighten the terminal screw.

Display indicator value is lower than the actual value or the indication value is unstable. There are metal chips and dust in the protection tube. Dirty between terminals and short-circuit of thermal resistance (water accumulation, etc.) Remove metal chips, clean dust, water droplets, etc., find short-circuit points, strengthen Insulation and so on.

The display meter indicates that the negative value indicates that the meter and the thermal resistance wiring are in error, or that the thermal resistance is short-circuited, correct the wiring, or find the short-circuit point and strengthen the insulation.

Change in resistance and temperature relationship The thermal resistance wire material is corroded and deteriorated to replace the resistor body (thermal resistance).

Starting from problems, discovering problems and solving problems can enable us to understand the instruments more deeply.

Nitrided Screw & Barrel

Nitrided Screw & Barrel,Conical Screw Barrel,Nitrided Parallel Screw And Barrel,Nitrided Parallel Twin Screw Barrel

Zhejiang Jinhai Plastic Machinery Co., Ltd. , https://www.jinhaiextruder.com

Posted on