Introduction to Goniophotometry and the LSG-6000
Goniophotometry is a critical photometric measurement technique used to evaluate the spatial distribution of luminous intensity, luminous flux, and color uniformity of light sources. The LISUN LSG-6000 goniophotometer represents a state-of-the-art solution for precise and repeatable photometric characterization, adhering to international standards such as IEC 60598, IES LM-79, CIE 70, and EN 13032-1.
Designed for high-accuracy testing in research, manufacturing, and quality control, the LSG-6000 integrates a dual-axis robotic movement system, high-resolution spectroradiometry, and advanced data acquisition software. Its applications span industries including LED manufacturing, display testing, medical lighting validation, and urban lighting design, ensuring compliance with stringent regulatory and performance benchmarks.
Technical Specifications and Measurement Principles
Key Specifications of the LSG-6000
| Parameter | Specification |
|---|---|
| Measurement Range | 0.1 to 1,000,000 cd |
| Angular Resolution | 0.01° (adjustable) |
| Distance Range | 5m to 30m (customizable) |
| Spectral Range | 380nm to 780nm (extendable to NIR/UV) |
| Compliance Standards | IEC 60598, IES LM-79, CIE 70, EN 13032-1 |
| Data Output | IES, LDT, EULUMDAT, XML |
Measurement Principles
The LSG-6000 operates on the far-field goniophotometric principle, where a photodetector or spectroradiometer measures luminous intensity at varying azimuth and elevation angles. The system employs a motorized dual-axis rotation mechanism to ensure precise angular positioning, while a high-sensitivity CCD or photodiode array captures spectral and spatial data.
Key measurement capabilities include:
- Luminous Intensity Distribution (LID) – Mapping candela values across hemispherical or full-sphere geometries.
- Total Luminous Flux – Integrating sphere validation via absolute photometry (CIE 84).
- Color Uniformity Analysis – Evaluating chromaticity shifts (Δu’v’) per ANSI C78.377.
- Beam Angle and Zonal Lumen Calculation – Critical for directional lighting (e.g., automotive, stage lighting).
Industry Applications and Compliance
1. LED and OLED Manufacturing
The LSG-6000 verifies IES LM-80 lumen maintenance and TM-21 extrapolation for LED packages. In OLED production, it assesses angular color consistency, a critical parameter for display uniformity per IEC 62341-6-1.
2. Display Equipment Testing
For LCD, microLED, and direct-view displays, the system measures viewing angle performance (contrast ratio, gamma shift) as per VESA DisplayHDR 1400 and IEC 62087.
3. Photovoltaic and Optical Component Validation
In PV module testing, the LSG-6000 quantifies angular-dependent reflectance/transmittance (ASTM E972), optimizing anti-glare coatings. Optical component manufacturers use it for BSDF (Bidirectional Scattering Distribution Function) analysis.
4. Medical and Scientific Lighting
Medical device lighting (e.g., surgical lamps) must comply with ISO 15004-2 and DIN 5035-7. The LSG-6000 ensures homogeneous illumination without stray light artifacts.
5. Urban and Architectural Lighting
Streetlight photometry (EN 13201) and glare analysis (CIE 112) rely on goniophotometric data for Dark Sky Compliance and energy efficiency.
Competitive Advantages of the LSG-6000
- Automated Multi-Standard Compliance – Simultaneous testing for IES, CIE, and EN standards reduces calibration overhead.
- High Dynamic Range (HDR) Photometry – Measures ultra-low to high-intensity sources (0.1 cd to 1 Mcd) without range switching.
- Modular Spectroradiometry – Optional HTS-1000 hyperspectral module enables SPD (Spectral Power Distribution) analysis.
- Robotic Precision – Servo-controlled axes achieve ±0.005° repeatability, surpassing manual goniometers.
Case Study: Stage Lighting Validation
A European theater lighting manufacturer used the LSG-6000 to validate a new RGBW LED spotlight against ESTA E1.54 (entertainment luminaire photometry). The system confirmed:
- Beam angle consistency (±2% deviation)
- Color mixing uniformity (Δu’v’ < 0.003 across 120° cone)
- Flicker compliance (Pst LM < 1.0 per IEEE 1789)
FAQ Section
Q1: How does the LSG-6000 handle near-field vs. far-field measurements?
The system defaults to far-field (5m+ distance) but supports near-field corrections via Rayleigh distance algorithms for compact sources.
Q2: What software interfaces are supported?
The LSG-6000 exports to IES, LDT, and EULUMDAT formats and integrates with MATLAB, LabVIEW, and Python via API.
Q3: Can it measure UV/IR-emitting sources?
Yes, with optional UV-340 or IR-950 filtered detectors, compliant with CIE S 019/E:2011.
Q4: What is the typical calibration cycle?
Annual NIST-traceable calibration is recommended, with onboard self-validation via internal reference LEDs.
Q5: How does it compare to integrating sphere methods?
Goniophotometry provides spatial resolution (angular data), whereas spheres measure total flux only. The LSG-6000 can cross-validate sphere data via absolute photometry.
This technical overview underscores the LSG-6000’s role as a benchmark instrument for photometric rigor across industries requiring precise luminous distribution analysis.
