With the increasing demand for equipment safety and operational efficiency in industries such as power, transportation, and petrochemicals, distributed fiber optic online temperature measurement technology has become the core means of real-time monitoring of temperature fields due to its advantages of long distance, high precision, and resistance to electromagnetic interference. This article will systematically analyze its core value from two aspects: technical principles and product characteristics.

1、 Working principle of distributed fiber optic online temperature measurement

（1） Optical time domain reflection（OTDR）Raman scattering effect

The system is based on optical time domain reflection technology, injecting pulsed light into the fiber through a laser. When light propagates in optical fibers, it interacts with molecular vibrations to produce Raman scattering light, including Stokes light（Stokes）Compared with anti Stokes light（Anti-Stokes）The intensity ratio is linearly related to temperature. By detecting the intensity changes of anti Stokes light, the temperature distribution along the fiber can be accurately calculated with spatial resolution up to0.5Meter, temperature measurement accuracy±1℃.

（2） Dual function of sensing fiber optic

Sensing fiber is both a signal transmission medium and a temperature sensor. Its coverage range is wide (single fiber can reach)50Kilometers can be laid along cables, pipelines, or equipment surfaces to collect real-time spatial temperature data. For example, in power cable monitoring, optical fibers can be laid closely to the cable to directly sense the temperature of the core, avoiding blind spots covered by traditional point sensors.

（3） Multi parameter fusion analysis

The system synchronously collects data such as operating current (measured by a Roche coil), ambient temperature, etc., and combines them withIEC60287TheIEC60853Algorithm model for real-time calculation of cable conductor temperature, steady-state current carrying capacity, and dynamic current carrying capacity. For example, given the ambient temperature and load current, the system can predict10The highest temperature of the cable within minutes provides decision-making basis for scheduling.

2、 Product characteristics of distributed fiber optic online temperature measurement

（1） Real time and long-distance monitoring

The system supports every second1The second temperature refresh rate can capture abnormal temperature rise in real time. Single host can be monitored50Kilometer fiber optic cables cover large power plants, cross regional power grids, or long-distance pipelines, reducing the number of sensor deployments and maintenance costs.

（2） Anti electromagnetic interference and intrinsic safety

Fiber optic cables transmit data through optical signals and are not affected by electromagnetic fields or high-voltage environments, making them suitable for strong electromagnetic scenarios such as substations and rail transit. At the same time, the characteristic of non electric signal transmission avoids the risk of electric sparks and meets the safety requirements of flammable and explosive places.

（3） Intelligent analysis and early warning

The system is equipped with an intelligent fire alarm algorithm that can identify abnormal modes such as sudden temperature changes and area overheating, and automatically trigger sound and light alarms or linked fire extinguishing devices. For example, in a cable tunnel, when the temperature in a certain area exceeds a threshold, the system can accurately locate the fault point and shorten the repair time.

（4） IoT Integration and Data Traceability

The data is uploaded to the cloud through the Internet of Things platform, supporting remote monitoring, historical data playback, and multi-dimensional analysis. Users can trace temperature curves at any time point and generate compliance reports to meet the needs of the power industryDL/T 1573-2016Waiting for standard requirements.

Conclusion

Distributed fiber optic online temperature measurement technology achieves real-time, accurate, and long-distance monitoring of temperature field through light scattering effect and multi parameter fusion analysis. Its anti-interference, intrinsic safety, and intelligent characteristics provide reliable equipment protection solutions for fields such as power, transportation, and petrochemicals, helping the industry transform towards digitalization and preventive maintenance.