Introduction
Integrating spheres are critical instruments in photometric and radiometric testing, providing uniform light diffusion for precise measurements of luminous flux, colorimetric properties, and spectral distribution. Among industry leaders, LISUN and Everfine produce high-performance integrating spheres, each with distinct design philosophies and technical specifications. This article examines the key differences between LISUN and Everfine integrating spheres, with a focus on the LISUN LPCE-3 Spectroradiometer Integrating Sphere System, its testing principles, and applications across multiple industries.
Fundamental Design and Construction Differences
1. Material and Coating Specifications
LISUN integrating spheres, including the LPCE-3, utilize high-reflectance barium sulfate (BaSO₄) or PTFE coatings, achieving reflectance rates exceeding 95%. This ensures minimal light absorption and superior uniformity for spectral measurements. Everfine spheres often employ similar materials but may vary in coating thickness and application methods, potentially affecting long-term stability.
2. Sphere Geometry and Port Configurations
The LPCE-3 features a modular design with multiple auxiliary ports for detector placement, sample holders, and external light sources. Everfine models typically follow standardized port arrangements, limiting flexibility in complex testing scenarios. LISUN’s optimized baffle design further reduces stray light interference, a critical factor in high-precision applications.
3. Thermal and Environmental Stability
LISUN integrates active thermal management in the LPCE-3, maintaining stable internal temperatures during prolonged operation—essential for LED and OLED testing where junction temperature affects spectral output. Everfine spheres rely on passive dissipation, which may introduce measurement drift under fluctuating ambient conditions.
Technical Specifications of the LISUN LPCE-3 System
The LPCE-3 Spectroradiometer Integrating Sphere System is engineered for comprehensive photometric and colorimetric analysis, adhering to CIE 177, CIE-13.3, LM-79, and EN13032-1 standards. Key specifications include:
| Parameter | LPCE-3 Specification |
|---|---|
| Sphere Diameter | 0.3m / 0.5m / 1m / 1.5m / 2m (customizable) |
| Coating Reflectance | ≥95% (BaSO₄ or PTFE) |
| Spectral Range | 380–780nm (extendable to 200–2500nm) |
| Detector Compatibility | High-resolution CCD array spectroradiometer |
| Measurement Parameters | Luminous flux, CCT, CRI, chromaticity coordinates, radiant power |
| Auxiliary Ports | Up to 6 (for reference detectors, external sources) |
Testing Principles and Methodologies
1. Absolute vs. Relative Measurement Modes
The LPCE-3 supports both absolute luminous flux measurements (using an internal calibrated lamp) and relative measurements (comparing test samples against references). Everfine systems often prioritize relative measurements, requiring external calibration for absolute data.
2. Spectral Correction and Self-Absorption Compensation
LISUN’s proprietary software corrects for self-absorption effects caused by large or high-power samples (e.g., automotive LED arrays). Everfine’s correction algorithms are less adaptive, potentially necessitating manual adjustments.
3. Multi-Channel Synchronization
For applications like display testing, the LPCE-3 synchronizes multiple detectors to measure angular-dependent color uniformity—a feature absent in most Everfine models.
Industry-Specific Applications
1. LED & OLED Manufacturing
The LPCE-3 verifies binning consistency and chromaticity stability in high-volume production, critical for meeting ANSI C78.377 and IEC 62931 standards.
2. Automotive Lighting Testing
Automotive headlamps and signal lights require precise luminous intensity profiling. The LPCE-3’s wide dynamic range accommodates high-luminance sources without saturation.
3. Aerospace and Aviation Lighting
Compliance with FAA AC 150/5345-46E mandates rigorous photometric validation. LISUN’s thermal-stable design ensures repeatability in variable-pressure environments.
4. Medical Lighting Equipment
Surgical and diagnostic lighting must adhere to ISO 15004-2. The LPCE-3’s spectroradiometric accuracy validates non-flicker and color rendering requirements.
Competitive Advantages of the LPCE-3
- Modular Expandability: Supports upgrades for UV/IR measurements.
- Automated Calibration: Reduces operator-dependent errors.
- Multi-Standard Compliance: Validates against LM-79, IESNA, and DIN protocols.
FAQ Section
Q1: How does the LPCE-3 compensate for self-absorption in large LED modules?
A1: The system employs a dual-beam correction method, subtracting the absorption artifact using a reference detector.
Q2: Can the LPCE-3 measure pulsed or flickering light sources?
A2: Yes, its high-speed CCD array captures transient waveforms up to 20kHz.
Q3: What is the typical calibration interval for the LPCE-3?
A3: Annual recalibration is recommended, though the system includes real-time drift monitoring.
Q4: Does the LPCE-3 support NIST-traceable calibration?
A4: Yes, LISUN provides NIST-traceable calibration certificates for all reference detectors.
Q5: How does the LPCE-3 handle high-power laser measurements?
A5: Optional attenuators and beam diffusers prevent detector saturation while maintaining spectral fidelity.
This analysis underscores the LPCE-3’s superiority in precision, adaptability, and compliance, making it the preferred choice for industries demanding uncompromising photometric accuracy.
