Introduction to Goniophotometric Measurement Systems
Goniophotometers are precision optical instruments designed to measure the spatial distribution of light emitted from luminaires, LEDs, and other light sources. These devices play a critical role in quantifying photometric properties such as luminous intensity, luminous flux, and beam angles, ensuring compliance with international standards. The LSG-6000 goniophotometer, developed by LISUN, exemplifies advanced engineering in this field, offering high-precision measurements for diverse industrial applications.
Fundamental Operating Principles of Goniophotometers
A goniophotometer operates by rotating a light source or detector along one or more axes to capture luminous intensity at varying angular positions. The LSG-6000 employs a Type C (moving detector, fixed light source) configuration, which minimizes errors associated with source movement. The system integrates a high-sensitivity spectrometer and photometer to measure spectral power distribution and illuminance, respectively. Data acquisition follows the inverse-square law, ensuring accurate far-field photometry.
Key Specifications of the LSG-6000 Goniophotometer
The LSG-6000 is engineered for high repeatability (±1%) and angular resolution (0.1°), meeting stringent industry demands. Its specifications include:
- Measurement Range: 0.1 to 200,000 cd (adjustable via neutral density filters)
- Angular Accuracy: ±0.2°
- Spectral Range: 380–780 nm (extendable to 200–2500 nm with optional modules)
- Compliance Standards: IEC 60598-1, IES LM-79, CIE 121, and EN 13032-1
- Maximum Luminaire Dimensions: 2,000 × 2,000 × 1,500 mm (customizable)
Testing Methodologies and Compliance with International Standards
The LSG-6000 adheres to IEC 60598-1 for safety and performance testing of luminaires, ensuring conformity in global markets. For LED manufacturers, IES LM-79-19 prescribes the measurement of total luminous flux, color characteristics, and electrical parameters. The system’s automated C-γ motion system enables precise polar and azimuthal scans, critical for evaluating asymmetric light distributions in urban lighting and stage equipment.
Industry-Specific Applications of Goniophotometry
LED and OLED Manufacturing
In LED production, the LSG-6000 validates angular color uniformity (CIE 177) and beam consistency. OLED displays require precise viewing-angle performance assessments, where goniophotometric data ensures adherence to VESA and DisplayHDR standards.
Photovoltaic and Optical Component Testing
For solar simulators and photovoltaic modules, the system quantifies spatial irradiance uniformity per IEC 60904-9. Optical component manufacturers rely on its data to calibrate lenses and diffusers for medical lighting and sensor systems.
Urban and Architectural Lighting Design
Municipalities and designers use goniophotometric reports to optimize streetlighting (EN 13201) and minimize light pollution. The LSG-6000’s large-diameter mirror design eliminates stray light interference, crucial for dark-sky compliance.
Competitive Advantages of the LSG-6000
Compared to conventional systems, the LSG-6000 offers:
- Modular Design: Supports upgrades for UV/IR measurements and high-speed sampling.
- Thermal Stability: Active cooling maintains detector accuracy during prolonged tests.
- Automated Calibration: Reduces operator dependency and enhances reproducibility.
Data Representation and Reporting Capabilities
The LSG-6000 generates IES, EULUMDAT, and LDT files for lighting design software like Dialux and Relux. Tabular outputs include:
| Parameter | Measurement Value | Tolerance |
|---|---|---|
| Luminous Flux | 4,200 lm | ±2% |
| CCT | 4,000 K | ±3% |
| Beam Angle (50%) | 45° | ±0.5° |
Frequently Asked Questions
Q1: How does the LSG-6000 handle high-power LED arrays exceeding 50,000 lm?
The system integrates calibrated attenuators and a water-cooled baffle to manage thermal load, ensuring measurement integrity.
Q2: Which standards validate its use for medical lighting testing?
The device complies with ANSI/IES RP-16-17 and ISO 15004-2 for ophthalmic and surgical luminaires.
Q3: Can it measure flicker percentage for display backlighting?
Yes, with an optional high-speed photodiode module, it captures flicker up to 20 kHz per IEEE 1789-2015.
Q4: What environmental controls are required for laboratory installation?
A temperature-stabilized (23±1°C), draft-free chamber with <5% relative humidity variation is recommended.
Q5: How does it compare to integrating sphere methods for total flux measurement?
Goniophotometry provides directional data absent in sphere tests, essential for applications requiring spatial light profiling.
