Infrared thermal‑imaging technology is based on the principle that all objects in nature with a temperature above absolute zero constantly emit infrared rays carrying characteristic information about the objects. This principle has led to the development of a passive infrared night‑vision technology. Infrared thermal‑imaging technology can improve the reliability and efficiency of railway safety protection systems. What are its applications in railway transportation? Below, the editorial team from Kaimorui shares relevant information on this topic.

Applications in Railway Transportation

1. 7×24‑hour all‑weather day‑and‑night monitoring of railway sections

In accordance with requirements set forth in documents such as Notice of China Railway Corporation on Issuing Supplementary Standards for Video Surveillance Setup for Railway Section Lines with a Designed Speed of 200 km/h and Above (Document No. TZJS〔2016〕18), full‑coverage video surveillance projects will be implemented for section lines of newly‑built railways with a designed speed of 200 km/h and above, to further strengthen safety protection along railway sections.

1. Inspection of section substations via temperature‑measurement functions of infrared thermal imagers

Efficient inspection of section substations has long been a challenge for railway power‑supply systems. Equipment temperature serves as a key indicator reflecting system operating conditions. Infrared thermal‑imaging technology monitors surface‑temperature distribution of substation equipment, offering timely insight into equipment status and effectively complementing visible‑light video surveillance systems. Potential equipment failures and safety hazards can be detected day or night, even under haze conditions. Alarms will trigger immediately upon abnormal temperature readings to prevent accidents.

1. Automatic alarm and protection against intrusions into railway sections

There are two main technical approaches for railway‑section automatic intrusion‑alarm systems:

• The first approach, specified in Interim General Technical Scheme for High‑Speed Railway Perimeter Intrusion Alarm System (Document No. TZJKJ〔2015〕233), adopts linkage between front‑end detectors (e.g. vibration optical fibre, infrared barriers) and the integrated video‑surveillance system. Although interface specifications are defined for the two subsystems, inconsistent construction timelines increase integration and commissioning complexity in practical projects. High false‑alarm rates from front‑end detectors are one factor limiting large‑scale deployment on railways.
• The second approach applies image‑analysis technology, complying with Performance Test Requirements for Video Content Analysis of Railway Integrated Video Surveillance System (Document No. YJTX〔2010〕527).

The above covers the key applications discussed. As modern infrared technology continues to mature, infrared thermal‑imaging has gained wide adoption across railway transportation. It delivers long‑distance, non‑contact, real‑time, fast on‑line monitoring of equipment operating status, and features high resolution, intuitive visual output, immunity to electromagnetic interference, and high operational safety. Fault diagnosis and analysis can be performed without power cuts, sampling or equipment disassembly.