Guide To: UNECE R31 - Headlamps - halogen sealed beam (HSB)
23 July 2023
Guide To: UNECE R31 - Headlamps - halogen sealed beam (HSB)
UN ECE Regulation No. 31 provides the uniform provisions for the approval of halogen sealed-beam headlamps (HSB units) used in motor vehicles. These headlamps are designed to emit either a European asymmetrical passing beam, a driving beam, or both. The regulation covers all technical and safety requirements to ensure proper headlamp performance, durability, and compliance for vehicles.
Scope of the Regulation
UN ECE R31 applies to:
- Halogen sealed-beam headlamps (HSB), which are used for producing passing and/or driving beams for motor vehicles, particularly in categories M, N, and T (passenger cars, goods vehicles, and tractors, respectively).
Key Features of UN ECE R31
Design and Construction:
- HSB units are headlamp systems with components like the reflector, optical system, and halogen light sources forming an indivisible unit. This construction ensures the unit cannot be dismantled without rendering it unusable.
- The regulation specifies that these headlamps should be equipped to provide either a passing beam, driving beam, or both, depending on the unit's type. These beams must meet specific light distribution standards to ensure road safety.
Testing Requirements:
- Photometric Testing: The regulation prescribes photometric tests to measure the light output of the headlamp. This ensures that the headlamp provides adequate illumination on the road without causing glare or discomfort to other drivers.
- Durability and Performance: The headlamp must endure various operational conditions, including exposure to heat, vibration, and environmental changes. Stability of performance is verified through endurance tests that simulate long-term use.
Marking and Approval:
- Each approved HSB unit must bear the manufacturer’s trade name or mark, along with the appropriate approval number. The approval mark signifies that the headlamp meets all the regulatory requirements.
- Grouped, combined, or reciprocally incorporated lamps are also allowed to bear a single international approval mark, provided all components meet the applicable regulations.
Light Colour and Intensity:
- The HSB units must emit white light for both passing and driving beams. Light intensity and beam focus are crucial elements tested to ensure optimal visibility for drivers and to avoid dazzling oncoming traffic.
Incorporation into UN ECE R148
The provisions of UN ECE R31 have been incorporated into UN ECE Regulation No. 148, which consolidates multiple vehicle lighting regulations into one streamlined framework. R148 covers all light-signalling devices, including headlamps like those outlined in R31. This consolidation simplifies the regulatory process and ensures harmonized standards for all vehicle lighting systems.
Conclusion
UN ECE R31 plays a vital role in regulating the design, performance, and approval of halogen sealed-beam headlamps, ensuring they meet international safety standards. The integration of this regulation into UN ECE R148 further supports the unification of vehicle lighting standards, helping manufacturers and regulatory bodies streamline compliance processes while maintaining high safety levels on the road.