Foss successfully completes circuit integrity test according to Metro curve (750°C)

Foss has once again demonstrated the reliability of its DB4678 fiber optic cables by successfully completing circuit integrity testing in combination with the KOPOS cable support system. The test was conducted under demanding fire conditions following the Metro curve (750°C), confirming the system’s performance in critical environments.

On February 18, 2026, Foss carried out fire resistance testing at the FIRES testing laboratory. The DB4678 fiber optic cable, installed together with the KOPOS cable supporting system, was exposed to fire conditions in a controlled chamber in accordance with the so-called Metro curve, reaching temperatures of up to 750°C.

The successful completion of this test verifies that the cable system maintains circuit integrity under high-temperature conditions. This is essential for installations in infrastructure projects such as tunnels, metro systems, transportation hubs, and other environments where fire performance and operational continuity are critical safety requirements.

By repeating and passing these rigorous tests, Foss continues to demonstrate its commitment to quality, safety, and compliance with demanding international standards. The combination of DB4678 fiber optic cables and KOPOS support systems provides a proven solution for projects where reliable data transmission must be maintained even in the event of fire.