Although thermocouples have the advantages of simple structure, stable performance and low failure rate, non-standard installation, improper model selection and irregular use in industrial on-site operation will still cause problems such as inaccurate temperature measurement, signal drift and equipment failure, affecting production process control and product quality. Formulating standardized use specifications and targeted fault prevention measures is crucial to give full play to the performance advantages of thermocouples and extend their service life.
Model matching selection is the primary link to prevent thermocouple faults. Different types of thermocouples have clear applicable temperature ranges and environmental adaptation characteristics. High-temperature working conditions above 1000℃ must be equipped with tungsten-rhenium or platinum-rhodium high-temperature thermocouples, and ordinary thermocouples cannot be used instead; corrosive chemical environments need to select anti-corrosion thermocouples; high-vibration mechanical equipment is suitable for spring-fixed and armored thermocouples; high-pressure pipeline scenarios must use high-pressure sealed thermocouples. Blind random model selection will lead to rapid equipment aging, failure and measurement error, causing unnecessary production losses.
Standardized installation and wiring are important guarantees for stable operation of thermocouples. During on-site installation, the thermocouple measuring end must be in close contact with the measured object to avoid virtual contact and gap, so as to prevent slow heat transfer and inaccurate temperature sensing. The installation position should avoid strong air flow scouring and direct high-temperature radiation to reduce environmental interference. At the same time, special supporting compensation wires must be used for wiring, and mixed use of different types of wires and wrong wiring are prohibited. The wiring laying should avoid strong electromagnetic interference equipment to prevent signal distortion and fluctuation.
Daily maintenance and regular calibration can effectively reduce thermocouple operation faults. In long-term industrial operation, thermocouple protective sleeves will accumulate dust, scale and corrosive attachments, which will affect heat transfer efficiency and cause measurement deviation. Regular cleaning of the protective sleeve surface and inspection of welding points and wiring firmness are required. In addition, affected by long-term high-temperature aging and material fatigue, the thermoelectric performance of thermocouples will drift slightly, so regular professional temperature calibration is needed to ensure the long-term accuracy of measurement data.
Timely elimination of common faults ensures the continuous operation of the temperature measurement system. Common faults of thermocouples include no signal output, unstable signal and large temperature deviation, which are mostly caused by wire breakage, virtual welding, loose wiring, failure of compensation wires and excessive dirt on the measuring end. On-site maintenance personnel need to master basic fault judgment and maintenance methods, quickly locate and solve problems, avoid long-term abnormal operation of equipment, ensure the stable operation of industrial temperature monitoring system, and maintain the continuity and stability of production.
