{"id":5978,"date":"2025-08-01T16:13:02","date_gmt":"2025-08-01T08:13:02","guid":{"rendered":"https:\/\/www.ledtestsystem.com\/?p=5978"},"modified":"2025-08-01T16:13:02","modified_gmt":"2025-08-01T08:13:02","slug":"principe-de-fonctionnement-du-goniophotometre","status":"publish","type":"post","link":"https:\/\/ledtestsystem.com\/fr\/blogs\/principe-de-fonctionnement-du-goniophotometre\/","title":{"rendered":"Principe de fonctionnement du goniophotom\u00e8tre"},"content":{"rendered":"<h2><strong>Fundamental Principles of Goniophotometric Measurement<\/strong><\/h2>\n<p>UN <a href=\"https:\/\/www.lisungroup.com\/products\/goniophotometer\/lm-79-moving-detector-goniophotometer.html\" target=\"_blank\" rel=\"noopener\"><a href=\"https:\/\/www.ledphotometer.com\/products\/lm-79-moving-detector-goniophotometer-mirror-type-c\/\" target=\"_blank\" rel=\"noopener\">goniophotom\u00e8tre<\/a><\/a> is a precision optical instrument designed to measure the spatial distribution of light emitted from a source. The device operates by rotating a photodetector or the light source along one or more axes to capture luminous intensity at varying angles. This enables the generation of a three-dimensional radiation pattern, critical for evaluating parameters such as luminous flux, beam angle, and candela distribution.  <\/p>\n<p>The core measurement principle relies on the inverse-square law, where the detector records luminous intensity at fixed distances while maintaining angular precision. The system integrates a spectroradiometer or photopic-filtered photodetector to ensure spectral accuracy, complying with international standards such as CIE 70, IES LM-79, and IEC 61341.  <\/p>\n<h2><strong>Mechanical and Optical Architecture of a Goniophotometer<\/strong><\/h2>\n<p>Modern <a href=\"https:\/\/www.lisungroup.com\/products\/goniophotometer\/lm-79-moving-detector-goniophotometer.html\" target=\"_blank\" rel=\"noopener\">goniophotom\u00e8tres<\/a>, such as the <strong><a href=\"https:\/\/www.lisungroup.com\/products\/goniophotometer\/\" target=\"_blank\" rel=\"noopener\">LISUN<\/a> LSG-6000<\/strong>, employ a dual-axis rotational mechanism to facilitate full spherical photometry. The instrument consists of:  <\/p>\n<ul>\n<li><strong>Rotating Arm Mechanism<\/strong>: A motorized goniometer arm that positions the detector at precise azimuthal (horizontal) and elevation (vertical) angles.  <\/li>\n<li><strong>Fixed or Movable Light Source Mount<\/strong>: Depending on configuration, the luminaire under test (LUT) may remain stationary while the detector moves, or vice versa.  <\/li>\n<li><strong>High-Sensitivity Photodetector<\/strong>: A CCD array or silicon photodiode calibrated to CIE photopic response (V(\u03bb) curve) for accurate luminous intensity measurement.  <\/li>\n<li><strong>Environmental Control<\/strong>: Darkroom or baffle systems to minimize stray light interference.  <\/li>\n<\/ul>\n<p>Le <strong>LSG-6000<\/strong> features a Type C goniophotometer design (moving detector, fixed light source), optimized for high-accuracy testing of LED modules, automotive lighting, and street luminaires.  <\/p>\n<h2><strong>Compliance with International Photometric Standards<\/strong><\/h2>\n<p>Goniophotometric testing adheres to stringent regulatory frameworks, ensuring consistency across industries. Key standards include:  <\/p>\n<ul>\n<li><strong>IEC 61341<\/strong>: Specifies center-beam intensity and beam angle measurements for reflector lamps.  <\/li>\n<li><strong>IES LM-79<\/strong>: Governs electrical and photometric testing of solid-state lighting products.  <\/li>\n<li><strong>CIE 70<\/strong>: Defines goniophotometry of luminaires for intensity distribution and glare evaluation.  <\/li>\n<li><strong>ANSI C78.377<\/strong>: Standardizes chromaticity and color consistency in LED lighting.  <\/li>\n<\/ul>\n<p>Le <strong>LSG-6000<\/strong> complies with these standards, making it suitable for global certification processes, including ENEC (Europe), UL (North America), and JIS (Japan).  <\/p>\n<h2><strong>Applications in LED and OLED Manufacturing<\/strong><\/h2>\n<p>In LED production, goniophotometry ensures uniformity in beam spread and color consistency. Manufacturers utilize the <strong>LSG-6000<\/strong> to:  <\/p>\n<ul>\n<li>Verify far-field intensity distribution for automotive headlamps (SAE J575).  <\/li>\n<li>Characterize OLED panel angular emission profiles for display uniformity.  <\/li>\n<li>Optimize secondary optics in horticultural LED grow lights (DLC QPL requirements).  <\/li>\n<\/ul>\n<h2><strong>Advanced Use Cases in Display and Photovoltaic Testing<\/strong><\/h2>\n<p>For display manufacturers, goniophotometers assess viewing-angle performance of LCDs and microLEDs. The <strong>LSG-6000<\/strong> measures:  <\/p>\n<ul>\n<li>Luminance fall-off at oblique angles (ISO 13406-2 for display defects).  <\/li>\n<li>Angular color shift in medical-grade monitors (IEC 60601-1-8).  <\/li>\n<\/ul>\n<p>In photovoltaics, the instrument evaluates anti-glare coatings and light-trapping structures in solar panels (IEC 60904-9).  <\/p>\n<h2><strong>Competitive Advantages of the LSG-6000 Goniophotometer<\/strong><\/h2>\n<p>Le <strong>LSG-6000<\/strong> distinguishes itself through:  <\/p>\n<ul>\n<li><strong>High Angular Resolution (0.1\u00b0 step precision)<\/strong>: Critical for narrow-beam optics testing.  <\/li>\n<li><strong>Automated Multi-Axis Control<\/strong>: Reduces operator error in large-scale testing.  <\/li>\n<li><strong>Modular Spectroradiometer Integration<\/strong>: Supports spectral power distribution (SPD) analysis per CIE 015:2018.  <\/li>\n<li><strong>Wide Dynamic Range (0.001 cd to 2,000,000 cd)<\/strong>: Accommodates low-luminance medical devices and high-intensity stadium lights.  <\/li>\n<\/ul>\n<h2><strong>Section FAQ<\/strong><\/h2>\n<p><strong>Q1: What is the maximum sample size supported by the LSG-6000?<\/strong><br \/>\nThe LSG-6000 accommodates luminaires up to 2 meters in length and 300 kg in weight, with customizable fixtures for irregular shapes.  <\/p>\n<p><strong>Q2: How does the LSG-6000 ensure compliance with LM-79\u2019s total flux requirements?<\/strong><br \/>\nIt employs an absolute calibration method using an integrating sphere reference, traceable to NIST or PTB standards.  <\/p>\n<p><strong>Q3 : Le LSG-6000 peut-il mesurer le scintillement de l'\u00e9clairage LED ?<\/strong><br \/>\nYes, when paired with a high-speed photodetector, it assesses temporal light modulation per IEEE 1789-2015.  <\/p>\n<p><strong>Q4: What industries benefit most from Type C goniophotometers?<\/strong><br \/>\nAutomotive, aerospace, and architectural lighting, where directional intensity profiling is critical.  <\/p>\n<p><strong>Q5: Does the LSG-6000 support near-field goniophotometry?<\/strong><br \/>\nNo, it is optimized for far-field measurements (&gt;5x the largest dimension of the LUT). For near-field analysis, a specialized scanner is required.<\/p>","protected":false},"excerpt":{"rendered":"<p>Fundamental Principles of Goniophotometric Measurement A goniophotometer is a precision optical instrument designed to measure the spatial distribution of light emitted from a source. The device operates by rotating a photodetector or the light source along one or more axes to capture luminous intensity at varying angles. This enables the generation of a three-dimensional radiation [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":3510,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[744],"class_list":["post-5978","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blogs","tag-goniophotometer-working-principle"],"_links":{"self":[{"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/posts\/5978","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/comments?post=5978"}],"version-history":[{"count":0,"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/posts\/5978\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/media\/3510"}],"wp:attachment":[{"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/media?parent=5978"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/categories?post=5978"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ledtestsystem.com\/fr\/wp-json\/wp\/v2\/tags?post=5978"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}