{"id":9101,"date":"2026-07-03T17:29:03","date_gmt":"2026-07-03T09:29:03","guid":{"rendered":"https:\/\/www.ledtestsystem.com\/?p=9101"},"modified":"2026-07-03T17:29:03","modified_gmt":"2026-07-03T09:29:03","slug":"optimizing-solid-state-lighting-performance-with-the-lisun-goniophotometer-system-for-precision-luminous-intensity-distribution-measurement","status":"publish","type":"post","link":"https:\/\/ledtestsystem.com\/it\/blog-2\/optimizing-solid-state-lighting-performance-with-the-lisun-goniophotometer-system-for-precision-luminous-intensity-distribution-measurement\/","title":{"rendered":"Optimizing Solid-State Lighting Performance with the LISUN Goniophotometer System for Precision Luminous Intensity Distribution Measurement"},"content":{"rendered":"

Optimizing Solid-State Lighting Performance with the LISUN<\/a> Goniophotometer System for Precision Luminous Intensity Distribution Measurement<\/strong><\/p>\n

Introduction<\/strong><\/p>\n

The proliferation of solid-state lighting (SSL), encompassing Light Emitting Diodes (LEDs) and Organic Light Emitting Diodes (OLEDs), has introduced unprecedented demands for photometric accuracy. Unlike conventional incandescent or fluorescent sources, SSL devices exhibit spatially non-uniform luminous intensity distributions (LID), color shifts as a function of angle (color over angle, CoA), and sensitivity to thermal management. The quantification of these parameters is not merely a quality assurance step but a foundational element of optical design, energy compliance, and application-specific optimization. The LISUN Goniophotometer System<\/strong>, specifically the LSG-6000<\/strong> and LSG-1890B<\/strong> models, provides a metrological framework capable of resolving these complexities. This article delineates the technical architecture, operational principles, and industry-specific applications of these systems, focusing on their role in delivering precise LID measurements that drive Performance optimization in SSL.<\/p>\n

1. Metrological Principles of Goniophotometric Luminous Intensity Distribution Acquisition<\/strong><\/p>\n

Goniophotometry is the absolute measurement technique for determining the spatial distribution of luminous intensity emanating from a luminaire or SSL source. The fundamental principle is based on the concept of a fixed detector and a rotating light source<\/strong>, which maintains the photometric distance condition (typically > 5\u201310 times the maximum luminaire dimension) to approximate a point source. The LISUN LSG-6000 and LSG-1890B operate under this paradigm, employing a rotation stage (C-axis)<\/strong> and an elevation axis (\u03b3-axis)<\/strong> to map the full sphere of emission.<\/p>\n

The measurement sequence generates a dataset comprising intensity values ( I(gamma, C) ) for each angular coordinate. This raw data is the basis for deriving Total Luminous Flux ((Phi)) via integration of the intensity distribution over solid angle:<\/p>\n

[
\nPhi = int{0}^{2pi} int<\/em>{0}^{pi} I(gamma, C) singamma , dgamma , dC
\n]<\/p>\n

The LISUN systems utilize a Class A photometric probe<\/strong> (cosine-corrected, V(\u03bb)-filtered) to ensure spectral matches to the photopic response curve of the human eye. For the LSG-6000, the system\u2019s high-precision stepper motors achieve an angular resolution of 0.1\u00b0<\/strong>, while the LSG-1890B offers 0.2\u00b0<\/strong> resolution, both adequate for detecting narrow beam angles typical of directional SSL products (e.g., MR16, PAR lamps).<\/p>\n

The measurement distance is critical. The LSG-6000, designed for larger luminaires (up to 30 kg payload), operates at a default distance of 3 m<\/strong>, whereas the LSG-1890B, optimized for medium-sized indoor and outdoor fixtures, works effectively at 2 m<\/strong>. This configuration minimizes near-field error, ensuring that the measured LID reflects the far-field distribution used in lighting design software such as DIALux or Relux.<\/p>\n

2. LSG-6000 and LSG-1890B: Architectural Specifications and Comparative Analysis<\/strong><\/p>\n

The differentiation between the LSG-6000 and LSG-1890B is primarily based on payload capacity, rotational accuracy, and spectral integration capabilities. Below is a technical comparison of these two systems, contextualized within the demanding requirements of SSL testing.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n
Parameter<\/strong><\/th>\nLSG-6000<\/strong><\/th>\nLSG-1890B<\/strong><\/th>\n<\/tr>\n<\/thead>\n
Luminaire Volume (max)<\/strong><\/td>\n600 mm diameter<\/td>\n400 mm diameter<\/td>\n<\/tr>\n
Maximum Weight<\/strong><\/td>\n30 kg<\/td>\n10 kg<\/td>\n<\/tr>\n
Angular Resolution (C-Axis)<\/strong><\/td>\n0.1\u00b0<\/td>\n0.2\u00b0<\/td>\n<\/tr>\n
Photometric Distance<\/strong><\/td>\n3 m (extendable)<\/td>\n2 m (fixed)<\/td>\n<\/tr>\n
Spectroradiometer Integration<\/strong><\/td>\nOptional (LSG-6000G model)<\/td>\nStandard (dual-channel)<\/td>\n<\/tr>\n
Standard Compliance<\/strong><\/td>\nCIE S023, IESNA LM-79-08<\/td>\nCIE S023, IESNA LM-79-08<\/td>\n<\/tr>\n
Typical Application<\/strong><\/td>\nStreet lighting, high-bay fixtures<\/td>\nIndoor panels, downlights, troffers<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

The LSG-6000G variant integrates a spectroradiometer<\/strong> for simultaneous measurement of luminous intensity and spectral power distribution (SPD) per angular step. This is instrumental for evaluating CoA, a critical metric for stage and medical lighting where color consistency is paramount.<\/p>\n

Conversely, the LSG-1890B is often selected for quality control laboratories in the LED manufacturing<\/strong> sector due to its lower footprint and faster cycle time. Both systems incorporate a darkroom enclosure<\/strong> to suppress ambient light contributions, a requirement for achieving the measurement uncertainty below \u00b12% as mandated by the IES LM-79-08 standard.<\/p>\n

3. Adherence to International Photometric Standards: CIE S023 and IES LM-79-08<\/strong><\/p>\n

For SSL products to gain market access in Europe, North America, and other regions, compliance with specific photometric testing protocols is mandatory. The LISUN Goniophotometer systems are explicitly designed to satisfy two core standards.<\/p>\n

CIE S023 \/ E:2011 (International Standard)<\/strong>
\nThis standard specifies the measurement of LID for electric lamps and luminaires using goniophotometry. It requires that the measurement distance be at least five times the largest dimension of the luminaire to minimize the near-field effect. Both LISUN models meet this criterion by default, with the ability to increase the photometric radius for high-flux sources.<\/p>\n

IESNA LM-79-08 (USA and Canada)<\/strong>
\nThis standard governs the electrical and photometric measurements of SSL products. It mandates:<\/p>\n