Method of using multimeter to detect the quality of thermocouple
Thermocouple is a commonly used temperature measuring element in temperature measuring instruments. It directly measures temperature and converts the temperature signal into a thermoelectric potential signal, which is then converted into the temperature of the measured medium through electrical instruments (secondary instruments). The appearance of various thermocouples often varies greatly due to their needs, but their basic structures are roughly the same. They are usually composed of main parts such as hot electrodes, insulation sleeves, and junction boxes, and are usually used in conjunction with display instruments, recording instruments, and electronic regulators.
Method of using a multimeter to check the quality of thermocouples
1. Before using a multimeter for testing, we first observe with the naked eye whether the protective tube is corroded, penetrated, or leaking. Then use a multimeter to measure the continuity. The resistance of the assembled thermocouple is generally not greater than 2 ohms, and the resistance of the network cable is generally not greater than 50 ohms. Generally, if it is greater than 1K, it can be determined that it is broken.
2. Measure the resistance value with a multimeter, and if the resistance exceeds 100K, it is considered faulty.
3. Use a multimeter ohmmeter to measure the thermocouple, adjust the resistance, connect both ends, and use a lighter to slightly heat it. If the multimeter pointer significantly increases or decreases, it indicates that it is good. If the pointer does not move, it indicates that it is already broken. You can use a multimeter to measure the voltage at both ends in millivolt range. If there is no voltage, it will malfunction.
