Introduction to Type C Goniophotometry
Type C goniophotometers are specialized instruments designed for the precise measurement of luminous intensity distribution, spatial color uniformity, and total flux of light sources. Unlike Type A or B goniophotometers, which are optimized for specific angular ranges, Type C systems employ a fixed vertical axis and a rotating detector or light source, enabling comprehensive hemispherical measurements. This configuration is particularly advantageous for evaluating large-area luminaires, LED modules, and display panels where angular light emission characteristics are critical.
The LISUN LSG-6000 represents a state-of-the-art Type C goniophotometer, engineered to comply with international standards such as IEC 60598-1, CIE 121, LM-79, and EN 13032-1. Its modular design and high-precision optical sensors make it indispensable across industries requiring rigorous photometric validation, including LED manufacturing, urban lighting design, and medical lighting equipment development.
Optomechanical Architecture of the LSG-6000 System
The LSG-6000 employs a dual-axis robotic arm structure with a ±0.05° angular resolution, ensuring repeatable measurements across a 360° horizontal and 180° vertical range. A high-sensitivity spectroradiometer or photodetector is mounted on the moving arm, while the test specimen remains stationary—a critical feature for minimizing mechanical stress on large or fragile luminaires.
Key mechanical specifications include:
- Rotation speed: Adjustable from 0.1° to 10°/s for dynamic or static measurements.
- Load capacity: Up to 50 kg, accommodating industrial-grade luminaires.
- Positioning accuracy: <0.1° for both axes, validated via laser interferometry.
Photometric and Radiometric Testing Principles
The system operates on the far-field inverse-square law principle, where the detector captures luminous intensity at varying angular positions to construct a 3D intensity distribution model. For spectral analysis, an integrated fast-scanning spectroradiometer (optional) measures correlated color temperature (CCT), color rendering index (CRI), and chromaticity coordinates (x, y) in compliance with CIE 15:2018 and ANSI C78.377.
A critical advantage of the LSG-6000 is its real-time thermal compensation, which mitigates measurement drift caused by ambient temperature fluctuations—a common challenge in OLED and high-power LED testing.
Compliance with International Standards
The LSG-6000 is designed to meet stringent regulatory requirements across multiple jurisdictions:
- IEC 60598-1: Safety and performance of luminaires.
- LM-79-19: Electrical and photometric measurements of solid-state lighting products.
- EN 13032-1: Photometric data reporting for lighting applications in the EU.
- JIS C 8152: Japanese Industrial Standards for LED modules.
For photovoltaic panel testing, the system can be configured to measure angular-dependent reflectance and transmittance, aligning with IEC 60904-1-2.
Industry-Specific Applications
LED and OLED Manufacturing
In LED production lines, the LSG-6000 verifies beam angle consistency, spatial color uniformity, and total luminous flux—parameters critical for automotive headlights and backlighting in consumer electronics.
Display Equipment Testing
For micro-LED and OLED displays, the system quantifies viewing-angle performance, ensuring compliance with VESA DisplayHDR standards.
Urban Lighting Design
Municipalities rely on goniophotometric data to optimize streetlight spacing and glare control, adhering to ANSI/IES RP-8-14 roadway lighting standards.
Medical Lighting Equipment
Surgical and diagnostic lighting must meet ISO 15004-2 for chromatic stability. The LSG-6000’s spectroradiometric capabilities ensure flicker-free and shadowless illumination.
Competitive Advantages of the LSG-6000
- Modular Expandability: Supports interchangeable detectors for UV, visible, and IR spectra.
- Automated Data Workflow: Direct export to IES, LDT, and EULUMDAT file formats for lighting simulation software.
- Thermal Stability Control: Active cooling maintains detector accuracy during prolonged tests.
- Multi-Standard Calibration: Traceable to NIST (USA), PTB (Germany), and NPL (UK).
Case Study: Stage Lighting Validation
A European theater upgraded to RGBW LED stage lights and used the LSG-6000 to validate beam homogeneity and dimming linearity per ESTA E1.54-2019. The system identified ±3% intensity deviation at 45° off-axis, prompting a reflector redesign.
FAQ Section
Q1: What is the maximum sample size the LSG-6000 can accommodate?
The system supports luminaires up to 2 meters in diameter and 50 kg in weight, with custom fixtures available for larger specimens.
Q2: How does the LSG-6000 handle high-power LEDs with significant thermal output?
Integrated Peltier-cooled detectors and active heat dissipation maintain measurement stability even at >100W input power.
Q3: Can the system measure flicker in PWM-driven LEDs?
Yes, with an optional high-speed photodiode module, it captures flicker percentage and frequency up to 20 kHz.
Q4: Which file formats are supported for photometric data export?
Standard outputs include IES, LDT, and CSV, compatible with DIALux, Relux, and AGi32.
Q5: Is the LSG-6000 suitable for bidirectional reflectance distribution function (BRDF) studies?
While primarily designed for emissive sources, a modified optical bench can be integrated for BRDF analysis in sensor R&D.
