Traffic and Automotive Luminaire Photometric Distribution Testing
Professional measurement system solutions
Traffic and Automotive Luminaire Photometric Distribution Testing
The photometric distribution of automotive headlamps (low/high beam), fog lamps and signal lamps directly determines night driving safety—insufficient illumination causes blind zones, excessive glare disturbs oncoming traffic. With the adoption of LED, laser headlamps, adaptive driving beam (ADB) and matrix pixel headlamps, photometric curve measurement requires not only traditional intensity distribution but also precise evaluation of dynamic beam patterns, cutoff line sharpness (G-value) and pixel-level beam changes. The CIE-recommended GMS-2000 A-α traffic and automotive luminaire goniophotometer is designed per GB, JIS, ECE, SAE, FMVSS108. It tests headlamps, tail lamps, turn signals, position lamps, fog lamps, high-mounted stop lamps, work lamps, side marker lamps, retroreflectors, warning triangles and retroreflective materials.
This solution uses a far-field goniophotometer (Type A) for R&D laboratories and third-party certification centres. System comprises precision goniometer (fixed horizontal axis, moving vertical axis, ±0.01° accuracy), high-precision photometer (CIE V(λ) matched) and darkroom (25 m or 30 m path). Point-by-point scanning records intensity at each H and V angle. Compliant with CIE 121. Data processing: iso-intensity curves, polar plots; extraction of ECE R112 points (B50L, 75R, 50R, 50V); cutoff inflection point and G-value; ADB zone/pixel analysis; left/right beam synthesis for road illuminance. Reports: photometric curves, iso-illuminance plots, regulation point tables; IES/CSV/LDT export.
Key Features
- Headlamp, fog lamp, signal lamp photometry for night safety; supports LED, laser, ADB, matrix pixel headlamps
- Far-field Type A goniometer: 0.1° accuracy, 0.01° resolution; 0.2% linearity; <0.1% stray light
- Intensity distribution, key point illuminance (B50L/75R/50R/50V), cutoff G-value, beam uniformity
- Dedicated software for headlamps, fog lamps, brake lamps, turn signals, etc.; regulation PASS/NG
- Precious metal turntable, continuous measurement; max 40 kg, φ800×800 mm
- ECE R112, R148, CIE 121, GB 4599, 25991, 5920; IES/CSV/LDT export
Core Application Scenarios
Why does automotive photometry matter for night driving safety?
Headlamp, fog lamp and signal lamp photometry directly affects night driving safety. Insufficient illumination causes blind zones; excessive glare disturbs oncoming traffic. With LED, laser, ADB and matrix pixel headlamps, precise measurement of intensity distribution, dynamic beam, cutoff G-value and pixel-level patterns is required. The GMS-2000 Type A far-field goniophotometer meets CIE 121 and these requirements.
How is cutoff line sharpness (G-value) measured?
Cutoff line quality is key for low beam: sharpness, position, inflection point and G-value. The GMS-2000 goniometer scans point-by-point for H/V intensity; dedicated software computes inflection point and G-value for ECE R112 compliance. Extracts B50L, 75R, 50R, 50V illuminance; auto PASS/NG report.
How are ADB and matrix pixel headlamps tested?
ADB and matrix pixel headlamps require zone or pixel intensity analysis. The GMS-2000 supports point-by-point scanning for full spatial data; evaluates dynamic beam and pixel-level patterns. Left/right low/high beam synthesis for road illuminance. IES/CSV/LDT export for optical design simulation.
Measurable parameters
Meet the standard requirements
- ECE R112 Motor vehicle headlamps (asymmetric low and/or high beam)
- ECE R148 Light signalling devices
- ECE R150 Retroreflective devices
- CIE 121 Photometry of motor vehicle headlamps
- GB 4599 Automotive road illumination devices and systems
- GB 25991 LED headlamps for motor vehicles
- GB 5920 Light signalling devices and systems
- GB 4785 Installation of external lighting
Test parameters
Measurement targets and key parameters
- Intensity distribution: H/V angle intensity, polar plot, iso-intensity curves
- Key point illuminance: B50L, 75R, 50R, 50V per ECE R112 (lx)
- Cutoff line: sharpness, angle deviation, inflection point, G-value
- Beam uniformity: smoothness, dark/light zones
- ADB/matrix: zone or pixel intensity distribution
System composition and operation
- Goniometer: Type A, fixed H + moving V axis, ±0.01°
- Photometer: high-precision probe or spectrometer, V(λ) matched
- Darkroom: 25 m or 30 m path, stray-light free
- Data acquisition: point-by-point scan, auto record
- Report: curves, iso-illuminance, regulation table; IES/CSV/LDT export
