Introduction to Goniophotometry and the LSG-6000 System
Goniophotometry is a fundamental measurement technique in photometric and radiometric analysis, enabling the precise characterization of luminous intensity distribution, spatial uniformity, and total flux of light sources. The LISUN LSG-6000 Goniophotometer is a state-of-the-art system designed for high-accuracy testing across diverse industries, including LED and OLED manufacturing, display equipment validation, and urban lighting design.
Compliant with IEC 60598-1, LM-79, CIE 70, CIE 121, and EN 13032-1, the LSG-6000 facilitates standardized photometric evaluations critical for product certification, R&D optimization, and quality assurance. Its modular design accommodates both laboratory and industrial environments, supporting light sources ranging from compact LEDs to high-power luminaires.
Technical Specifications and Measurement Capabilities
The LSG-6000 integrates a high-precision dual-axis goniometer with a spectroradiometer or photometer, enabling comprehensive luminous intensity distribution (LID) analysis. Key specifications include:
| Parameter | Specification |
|---|---|
| Measurement Range | 0.1 lm – 200,000 lm |
| Angular Resolution | 0.1° (adjustable) |
| Goniometer Accuracy | ±0.05° |
| Spectral Range | 380 nm – 780 nm (extendable to 1700 nm with optional modules) |
| Compliance Standards | IEC, CIE, LM-79, EN, DIN, JIS |
| Maximum Sample Weight | 50 kg (110 lbs) |
| Data Output Formats | IES, LDT, EULUMDAT, CSV |
The system employs a Type C (moving detector, fixed light source) configuration, minimizing measurement errors associated with sample movement. A temperature-stabilized photodetector ensures repeatability within ±1% under controlled conditions.
Testing Principles and Methodologies
Luminous Intensity Distribution (LID) Analysis
The LSG-6000 measures angular luminous intensity using a calibrated photometer or spectroradiometer positioned at a fixed distance from the light source. By rotating the sample along vertical (γ-axis) and horizontal (C-axis) planes, the system constructs a 3D intensity map, essential for beam angle determination and glare evaluation.
Total Luminous Flux Measurement
Integrating sphere methods are often supplemented by goniophotometry for absolute flux validation. The LSG-6000 calculates total flux via near-field goniophotometry (NFG), eliminating errors from sphere spatial non-uniformity, particularly for directional light sources.
Spectral and Colorimetric Characterization
Optional spectroradiometric modules enable color rendering index (CRI), correlated color temperature (CCT), and chromaticity coordinate (CIE 1931/1976) analysis, critical for medical lighting and display calibration.
Industry Applications and Compliance Standards
1. LED and OLED Manufacturing
The LSG-6000 verifies compliance with ANSI/IES LM-79 for LED efficacy and IEC 62612 for self-ballasted LED performance. Manufacturers utilize its high angular resolution to optimize secondary optics in automotive and architectural lighting.
2. Display Equipment Testing
For OLED and micro-LED displays, the system measures viewing angle uniformity per IEC 62341-6-2, ensuring consistent luminance and chromaticity across ±85° viewing cones.
3. Urban and Architectural Lighting
Municipalities and designers rely on the LSG-6000 to assess upward light ratio (ULR) and obtrusive light per CIE 150:2017, ensuring compliance with dark-sky regulations.
4. Stage and Studio Lighting
Theatrical luminaires are evaluated for beam homogeneity and far-field intensity to meet ESTA E1.48 guidelines for entertainment lighting.
5. Medical Lighting Equipment
Surgical and diagnostic luminaires require adherence to ISO 9680, where the LSG-6000 validates shadow dilution and color rendering for critical visual tasks.
Competitive Advantages of the LSG-6000
- High-Angular Precision – ±0.05° encoder accuracy surpasses typical ±0.1° industry benchmarks.
- Modular Expandability – Supports spectroradiometers, high-speed photometers, and IR/UV detectors.
- Automated Compliance Reporting – Direct export to IES and LDT formats streamlines certification workflows.
- Thermal Compensation – Active cooling minimizes drift in high-power LED testing.
Case Study: LSG-6000 in Photovoltaic Panel Inspection
A European solar research laboratory employed the LSG-6000 to evaluate bifacial photovoltaic modules under IEC 60904-1 and ASTM E424-71. By mapping angular reflectivity and transmittance, the team optimized anti-glare coatings, increasing panel efficiency by 2.3%.
FAQ Section
Q1: How does the LSG-6000 correct for ambient light interference?
The system employs a synchronous detection circuit and dark-room calibration to negate ambient contributions, ensuring accuracy within ±0.5% under controlled conditions.
Q2: Can the LSG-6000 measure pulsed or dimmable light sources?
Yes, with an optional high-speed photometer (1 MHz sampling rate), it captures PWM and dynamic dimming waveforms per IEC 61000-3-2.
Q3: What is the maximum sample size supported?
The standard stage accommodates samples up to 1.2 m in diameter; custom configurations extend this to 2.5 m.
Q4: Does the system support automated multi-axis movement for complex geometries?
Yes, programmable γ-C-γ sequences enable testing of asymmetric luminaires, such as automotive headlamps.
Q5: How does NFG compare to integrating sphere measurements?
NFG eliminates sphere errors for directional sources but requires longer measurement times. The LSG-6000 hybrid mode combines both methods for efficiency.
