Thermocouple is widely used in industrial production. So there is no doubt that a lot of problems will be encountered. If there are problems, how can we solve them?
I will list some common problems for you.
1. Remove the thermocouple from the input end of the instrument thermocouple, and then use any wire to short circuit the input end of the instrument thermocouple. When powered on, the display value of the digital tube on the upper row of the instrument is about room temperature, indicating that the internal wiring of the thermocouple is open, and the same type of thermocouple should be replaced. If it is still in the condition mentioned above, it means that the input end of the instrument is damaged during transportation and the instrument should be replaced.
2. Remove the thermocouple of the above fault instrument and replace it with the thermocouple connected to the same graduation meter which is running normally nearby. After power on, when the digital tube on the upper row of the original fault instrument shows the temperature of heating, it indicates that the internal wiring of the thermocouple is open, and replace the same type of thermocouple. If it is still in the condition mentioned above, it means that the input end of the instrument is damaged during transportation, and the instrument should be replaced.
3. Remove the faulty thermocouple from the instrument, put the multimeter at the ohm (R) * 1 level, and use two multimeter rods to measure both ends of the thermocouple. If the resistance value shown on the multimeter is large, it indicates that the internal connection of the thermocouple is open, so replace the same type of thermocouple. Otherwise, there is a certain resistance value, indicating that there is something wrong with the input end of the instrument, and the instrument should be replaced.
4. The wiring is correct according to the wiring diagram of the instrument. If the digital tube on the upper row of the instrument shows negative value after the instrument is powered on, it indicates that the thermocouple connected to the instrument "+" and "-" are connected incorrectly. Just change it.
5. The wiring is correct. When the instrument is running, the temperature displayed by the digital tube on the upper row of the instrument differs from the actual measured temperature by 40 ~ 70 degrees. The difference is even greater, indicating that the graduation number of the instrument is wrong with that of the thermocouple. According to the corresponding relationship between the temperature of thermocouples such as B, s, K, e and the millivolt (MV) value, under the same temperature condition, the millivolt value (MV) produced by B is the smallest, s is the second, K is larger, and E is the largest.
On 2018-08-08 11:45:46
