What temperature instrument is used for checking trains for overheating wheel bearings as they pass by a station?

The temperature instrument used for checking trains for overheating wheel bearings as they pass by a station is typically an infrared thermal camera or thermal imaging system. These devices can quickly measure the surface temperature of the wheel bearings without physical contact, allowing for real-time monitoring. By detecting unusual temperature increases, operators can identify potential issues and take preventive measures to ensure safety.