In industrial production temperature measurement, industrial thermocouples often have various failures occasionally, which ignites the accuracy of temperature measurement and brings trouble to employees. In order to quickly deal with various types of faults in the production of industrial thermocouples, this paper describes the failure analysis and treatment methods of industrial thermocouples in production.
1. In the measurement of production temperature of industrial thermocouples, if the thermoelectric potential of the thermocouple is found to be smaller than the actual value, it may be caused by the following reasons:
1. Short circuit.
2. The compensation wire is short-circuited due to insulation burnout.
3. Short circuit between the terminals in the thermocouple junction box.
4. The compensation wire and the thermocouple are reversed in polarity.
5. The compensation wire does not match the thermocouple.
6. The temperature of the cold junction of the thermocouple is too high.
7, the insertion depth is not enough and the installation position is wrong.
The correct way to handle:
1. If it is caused by moisture, it can be dried; if it is poorly insulated due to porcelain tube, it should be replaced.
2. Reinsulate the short circuit or replace the new compensation wire.
3. Open the junction box and clean the wiring board.
4. Reconnect correctly.
5. Replace with the same type of compensation wire.
6. The connecting wire of the thermocouple is replaced by a compensation line, so that the cold end is removed from the high temperature zone.
7. Change the installation position and insertion depth.
2. In the measurement of production temperature of industrial thermocouples, if the thermoelectric potential of the thermocouple is found to be larger than the actual value, it may be caused by the following reasons:
1. The insertion depth is not enough or the installation position is incorrect.
2. The compensation wire does not match the thermocouple model.
3. The hot electrode is deteriorated.
4. The temperature of the thermocouple reference terminal is too high.
5. There is interference signal entering.
The correct way to handle:
1. Change the position or insertion depth of An [Industrial Electrical Network-cnelc]
2. Replace the compensation wire of the same type.
3. Replace the thermocouple.
4. Adjust the reference temperature or make corrections.
5. Check the source of interference and eliminate it.
3. In the measurement of production temperature of industrial thermocouples, if the thermocouple potential error is found to be large, it may be caused by the following reasons:
1. The hot electrode is deteriorated.
2. The surface area of ​​the thermocouple protection sleeve is excessive.
3. The installation position and installation method of the thermocouple are improper.
4. The thermocouple loop is broken.
5. Measure line short circuit (thermocouple and compensation wire).
6. The terminal is loose.
The correct way to handle:
1. Replace the thermocouple.
2. Clean the surface area of ​​the thermocouple protection sleeve.
3. Change the installation location and installation method.
4. Find the broken line and reconnect.
5. Replace the insulation at the short circuit.
6. Tighten the terminal block.
4. In the measurement of production temperature of industrial thermocouples, if the indication of the measuring instrument is found to be unstable, sometimes there is no time, and the time is high and low, which may be caused by the following reasons:
1. The thermocouple has intermittent short circuit or intermittent grounding.
2. The hot electrode is in poor contact at the terminal.
3. The thermocouple is not installed securely and swings.
4. The hot electrode is broken or broken.
5. The compensation wire has grounding or intermittent short circuit.
The correct way to handle:
1. Remove the thermocouple's hot electrode from the protective tube, find the fault point and eliminate it.
2. Reconnect.
3. The installation is firm.
4. Replace the new electrode.
5. Identify the fault point and eliminate it.
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