The distributed fiber optic online temperature measurement system is widely used for temperature monitoring in fields such as power cables, rail transit, and petroleum and petrochemical industries due to its advantages of long distance, high precision, and resistance to electromagnetic interference. To ensure the long-term stable operation of the system, it is necessary to establish a full cycle maintenance plan that covers daily inspections, regular maintenance, fault handling, and data management. This article will discuss from three aspects: maintenance cycle, key links, and optimization suggestions.

1、 Daily inspection and basic maintenance

（1） Equipment appearance and operation status inspection

Daily inspections need to confirm the appearance integrity of temperature measurement hosts, fiber optic splice boxes, power modules, and other equipment, and check whether the status of indicator lights (such as running lights and alarm lights) is normal. For example, if the power indicator light of the host flashes, it may be due to abnormal power supply, and the power line needs to be checked immediatelyUPSstatus At the same time, record the ambient temperature and humidity to ensure that the operating environment of the equipment meets the requirements (usually temperature)0-40℃, humidity≤85%）.

（2） Fiber optic line inspection

Conduct weekly visual inspections of fiber optic cable laying paths, with a focus on identifying the following risk points:

mechanical damageCheck whether the optical fiber is damaged or has a bending radius that is too small due to construction or animal gnawing (the curvature radius needs to be maintained)≥10Times the diameter of the optical fiber).

Environmental interference: Confirm whether the optical fiber is close to heat sources, strong electromagnetic fields, or corrosive substances. For example, optical fibers in substations should be kept away from high-voltage equipment to avoid induced voltage interference.

Connection point status: Check whether the fiber fusion point or cold junction is loose or oxidized, and use if necessaryOTDR(Optical Time Domain Reflectometer) Test for Connection Loss (should be)≤0.1dB）.

（3） Preliminary data analysis

Log in to the system backend daily to view real-time temperature curves and alarm records. If the temperature in a certain area continues to be high or fluctuates abnormally, it is necessary to comprehensively judge whether it is equipment failure or load abnormality based on data such as current and ambient temperature. For example, a sudden increase in cable surface temperature10℃But the current remains unchanged, which may indicate a malfunction of the fiber optic sensor.

2、 Regular maintenance and deep calibration

（1） Quarterly maintenance: Hardware performance testing

Conduct a comprehensive hardware inspection every quarter, including:

Laser power test: Use an optical power meter to measure the output power of the laser. If the attenuation exceeds the initial value30%The laser module needs to be replaced.

Detector sensitivity calibration: Input a known intensity light signal through a standard light source (such as a tunable laser) to verify whether the detector output voltage is within the calibration range.

Cleaning of heat dissipation system: Clean the dust accumulation on the host fan and heat sink to ensure heat dissipation efficiency and avoid device performance degradation caused by overheating.

（2） Annual Maintenance: System Accuracy Calibration and Fiber Optic Testing

Implement annual system accuracy calibration and fiber performance evaluation:

Temperature calibration: Place a standard temperature sensor and a fiber optic sensor in a constant temperature chamber, compare their readings, and if the deviation is greater than±1℃Adjust system parameters or replace fiber optic cables.

Fiber loss testing: usingOTDRTest the overall loss of the fiber optic cable, if the total loss exceeds the initial value20%(such as multimode fiber optic)≤3dB/km）The loss point needs to be located and repaired.

Software version upgrade: Check if the system software is the latest version, update algorithm models and alarm thresholds, and improve the accuracy of anomaly recognition.

3、 Emergency handling of faults and data management

（1） Common fault classification and handling

Data Interruption: Check if the fiber optic cable is broken (using)OTDRCheck if the network connection between the host and the upper computer is normal, and if necessary, fuse the fiber optic cable or restart the network equipment.

Abnormal temperature: If the temperature of a certain channel continues to be0℃Or the maximum value may be due to sensor failure, and the fiber optic cable section needs to be replaced or the sealing of the splice box needs to be checked.

False alarm: Adjust the alarm threshold or optimize the alarm algorithm, such as eliminating short-term temperature rise false alarms caused by environmental temperature fluctuations.

（2） Data backup and security

Monthly backup of system historical data (including temperature curves, alarm records, and operation logs), stored on independent servers or cloud platforms. At the same time, set data access permissions to prevent unauthorized modifications. For example, the power industry needs to meetDL/T 1573-2016The requirements for data traceability in the standard.

Conclusion

The maintenance of distributed fiber optic online temperature measurement system requires“Prevention first, quick response”As a principle, ensure the long-term stable operation of the system through daily inspections, regular calibration, and emergency response to faults. By combining IoT platforms with big data analysis technology, maintenance intelligence can be further achieved, such as predicting fiber lifespan through machine learning and developing replacement plans in advance. A standardized maintenance plan can not only extend the service life of equipment, but also provide solid guarantees for the safe operation of critical infrastructure.