{"id":8811,"date":"2026-05-26T09:49:19","date_gmt":"2026-05-26T01:49:19","guid":{"rendered":"https:\/\/www.ledtestsystem.com\/?p=8811"},"modified":"2026-05-26T09:49:19","modified_gmt":"2026-05-26T01:49:19","slug":"advanced-ulbricht-sphere-applications-in-led-and-lighting-industries","status":"publish","type":"post","link":"https:\/\/ledtestsystem.com\/ru\/%d0%b1%d0%bb%d0%be%d0%b3%d0%b8\/advanced-ulbricht-sphere-applications-in-led-and-lighting-industries\/","title":{"rendered":"Advanced Ulbricht Sphere Applications in LED and Lighting Industries"},"content":{"rendered":"

Title:<\/strong> Advanced Ulbricht Sphere Applications in LED and Lighting Industries: Leveraging the \u041b\u0418\u0421\u0423\u041d<\/a> LPCE-2 \/ LPCE-3 Spectroradiometer \u0418\u043d\u0442\u0435\u0433\u0440\u0438\u0440\u0443\u044e\u0449\u0430\u044f \u0441\u0444\u0435\u0440\u0430<\/a> System for High-Precision Photometric, Colorimetric, and Radiometric Characterization<\/p>\n

\u0410\u0432\u0442\u043e\u0440:<\/strong> Technical Documentation Division, Photometric Metrology Group<\/p>\n

Date:<\/strong> October 2025<\/p>\n

\n

Introduction: The Ubiquity of the Ulbricht Sphere in Modern Photometry<\/h3>\n

The Ulbricht sphere, an integrating sphere<\/a> with a highly reflective Lambertian inner coating, remains the cornerstone of accurate flux measurement in solid-state lighting (SSL). As LED efficacy and color quality have reached levels demanding sub-0.5% measurement uncertainty, the sphere\u2019s role has transcended simple lumen measurement. It now serves as the primary platform for spectral flux determination, angularly integrated colorimetric analysis, and total radiant power measurement across multiple spectral bands.<\/p>\n

The advancement from single-channel photodetectors to array-based spectroradiometers has unlocked a new class of applications. Systems such as the LISUN LPCE-2 (LMS-9000C) and LPCE-3<\/strong> integrate a high-reflectivity coated sphere with a CCD-based spectroradiometer, enabling simultaneous measurement of all photometric and colorimetric parameters in accordance with CIE 127:2007, IESNA LM-79-19, and Energy Star requirements. This article delineates the advanced applications of such systems across a spectrum of high-stakes industries.<\/p>\n

\n

1. High-Fidelity Luminous Flux and Efficacy Verification in High-Power LED Modules<\/h3>\n

In the lighting industry, the characterization of high-power LED modules\u2014often exceeding 10,000 lm\u2014presents significant challenges due to self-heating and spatial flux non-uniformity. The LISUN LPCE-2 system, equipped with a 2-meter integrating sphere, mitigates these issues through its robust thermal management interface and high-speed data acquisition.<\/p>\n

The LPCE-2\u2019s spectroradiometer, covering 380 nm to 780 nm with a wavelength accuracy of \u00b10.3 nm, allows for direct calculation of total luminous flux (\u03a6v) from the spectral power distribution (SPD). Unlike goniophotometry, which requires hours of measurement, the sphere method delivers results in seconds. For efficacy (lm\/W) validation, the system simultaneously measures electrical parameters (voltage, current, power factor) via an integrated power meter at accuracy levels of 0.2% reading + 0.1% range.<\/p>\n

This capability is essential for manufacturers adhering to DLC (DesignLights Consortium) premium requirements, where efficacy thresholds are strictly enforced. The LPCE-2\u2019s auxiliary lamp substitution method, per CIE 84, corrects for spatial non-uniformity of the LED source, achieving a flux measurement uncertainty of <1% (k=2).<\/p>\n

\n

2. Colorimetric Tolerancing for Automotive Forward-Lighting and Signal Lamps<\/h3>\n

Automotive lighting testing (ECE R119, R123, SAE J578) demands rigorous chromaticity control. Headlamps, fog lamps, and turn signals must fall within defined color regions on the CIE 1931 or 1976 UCS chromaticity diagram. The LPCE-3 spectroradiometer, with its high dynamic range and low stray light (<0.01%), is uniquely suited for this task.<\/p>\n

The LPCE-3 operates with a 35 mm or 50 mm diameter sphere for small components (e.g., chip-on-board LEDs for matrix beams) or a 300 mm sphere for complete lamp assemblies. The system computes correlated color temperature (CCT), Duv (distance from Planckian locus), and dominant wavelength with a reproducibility of \u00b10.0015 in u\u2018v\u2019 coordinates. For red signal lamps (peak ~630 nm), the system\u2019s spectral resolution of 0.2 nm ensures accurate isolation of side-lobe emissions.<\/p>\n

A typical test sequence for automotive clients involves:<\/p>\n

    \n
  1. Warm-up stabilization<\/strong> to Tj = 85\u00b0C (simulated via the LPCE-2\u2019s temperature-controlled base).<\/li>\n
  2. Stray light correction<\/strong> using a dark spectrum and a spectral stray light matrix.<\/li>\n
  3. Color rendering index (CRI) and TM-30 Rf\/Rg calculation<\/strong> for interior ambient lighting.<\/li>\n<\/ol>\n

    The system\u2019s compliance with automotive thermal cycling requirements eliminates erroneous shifts due to detector drift, a common failure point in older photometer-based systems.<\/p>\n

    \n

    3. Radiometric Calibration for Ophthalmic and Surgical Medical Lighting Equipment<\/h3>\n

    Medical lighting equipment\u2014including surgical luminaires, slit lamps, and phototherapy devices\u2014requires stringent characterization of spectral radiance and total radiant power, particularly in UV (280\u2013400 nm) and photopic (500\u2013650 nm) bands. The International Electrotechnical Commission (IEC 60601-2-41) mandates spectral measurement of these sources for patient safety.<\/p>\n

    The LISUN LPCE-2 system, when configured with a quartz window port, enables accurate radiometric measurements in the UV-A (315\u2013400 nm) region. The sphere coating (BaSO4 or PTFE-based) must exhibit high reflectance (>95%) at 300 nm. The LPCE-2\u2019s spectroradiometer features a back-thinned CCD array with enhanced quantum efficiency in the UV, allowing detection of fluence rates as low as 0.5 \u03bcW\/cm\u00b2.<\/p>\n

    In a typical ophthalmological application:<\/p>\n

      \n
    • Blue light hazard (LB)<\/strong> calculation per IEC 62471 requires weighted integral of spectral radiance from 300 nm to 700 nm.<\/li>\n
    • The LPCE-2 outputs the blue light hazard weighted irradiance, E_B, to within 5% uncertainty.<\/li>\n
    • Photostability testing<\/strong> of pharmaceutical substrates under UV light requires controlled spectral output; the system verifies the coincidence of lamp spectrum with action spectra.<\/li>\n<\/ul>\n

      This capability is equally critical for photovoltaic industry<\/strong> standards, where spectral mismatch correction for solar simulators (IEC 60904-9) is performed using the sphere\u2019s spectral measurement at the device-under-test (DUT) plane.<\/p>\n

      \n

      4. Angularly Integrated Color Uniformity Assessment in Display Equipment and OLED Panels<\/h3>\n

      Display equipment testing, particularly for organic light-emitting diodes (OLED) and micro-LED arrays, presents a unique metrological challenge: these sources exhibit angle-dependent color shifts (i.e., blue shift in OLED at large viewing angles). A conventional plane detector measurement fails to capture the human-perceived color of such sources.<\/p>\n

      The LPCE-3, when paired with a 1-meter integrating sphere and a fiber-coupled spectrometer, performs total color flux<\/strong> measurement. This technique integrates the SPD over the entire 2\u03c0 steradian emission, providing a single colorimetric value representative of the device\u2019s angularly averaged appearance. This parameter is critical for urban lighting design<\/strong> where diffused lighting (e.g., streetlights) must avoid color breakup in wet conditions.<\/p>\n

      For OLED display manufacturers, the system calculates:<\/p>\n

        \n
      • \u0394u\u2018v\u2019<\/strong> (color angular uniformity) by rotating the DUT at multiple polar angles and capturing spectra.<\/li>\n
      • Temporal stability of chromaticity<\/strong> during dimming (PWM frequency effects).<\/li>\n<\/ul>\n

        The LPCE-2\u2019s low noise floor (0.0001 cd\/m\u00b2 equivalent) enables measurement of dimmed states down to 1% output\u2014essential for HDR display qualification.<\/p>\n

        \n

        5. Multi-Modal Measurement for Aerospace, Aviation, and Navigation Lighting<\/h3>\n

        Aerospace and aviation lighting systems\u2014including runway edge lights, obstruction beacons, and cockpit instrumentation\u2014require simultaneous compliance with SAE AS8028<\/strong> (incandescent replacement) and FAA AC 150\/5345-53<\/strong> (LED luminaires). These standards demand measurement of chromaticity coordinates, intensity (candela), and flash characteristics.<\/p>\n

        The LISUN LPCE-2 serves as a primary instrument for:<\/p>\n

          \n
        • Photopic and scotopic flux measurement<\/strong> for night-vision compatibility (NVIS).<\/li>\n
        • Color fidelity<\/strong> for red and green navigation lights, where CIE chromaticity boundaries are narrow (e.g., red: x > 0.710, y < 0.284).<\/li>\n
        • Flash energy calculation<\/strong> for strobe lights (W\u00b7s per flash).<\/li>\n<\/ul>\n

          The system\u2019s spectroradiometer operates in triggered mode, synchronized with the flash via an optical sensor. The large dynamic range (16-bit ADC) captures the full flash profile, computing peak intensity, total flux, and flash duration per FAA standards.<\/p>\n

          In marine and navigation lighting<\/strong>, the system verifies color stability over temperature (\u221230\u00b0C to +55\u00b0C) using the LPCE-2\u2019s environmental chamber integration. The sphere\u2019s large port fraction (0.05) ensures that the lamp\u2019s spatial emission is fully captured without self-shadowing.<\/p>\n

          \n

          6. Spectral Power Distribution Analysis for Stage and Studio Lighting Fixtures<\/h3>\n

          Stage and studio lighting requires precise spectral matching\u2014particularly for film and video applications. The LPCE-3<\/strong> facilitates measurement of:<\/p>\n

            \n
          • Spectral composition<\/strong> of LED-based D65, D50, or tungsten-like white sources.<\/li>\n
          • TLCI (Television Lighting Consistency Index)<\/strong> \u0438 TM-30-18<\/strong> fidelity (Rf) and gamut (Rg).<\/li>\n<\/ul>\n

            The system\u2019s spectral resolution of 0.4 nm FWHM allows discrimination of narrow-band phosphors used in RGB LED fixtures. For multi-chip fixtures (e.g., RGBA or CCT\u2013variable luminaires), the LPCE-2 performs an automated sequential measurement by switching channels via a built-in relay matrix.<\/p>\n

            An optical instrument R&D<\/strong> team might use the LPCE-2 to develop a custom daylight simulator by measuring the spectral match to ISO 23603, then adjusting LED drive currents based on the spectrum.<\/p>\n

            \n

            7. Core Specifications of the LISUN LPCE-2 \/ LPCE-3 Integrating Sphere and Spectroradiometer System<\/h3>\n

            The following table summarizes the key technical specifications for the LISUN LPCE-2 (LMS-9000C) and LPCE-3 systems, as used in the applications herein.<\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
            \u041f\u0430\u0440\u0430\u043c\u0435\u0442\u0440<\/th>\nLPCE-2 (LMS-9000C)<\/th>\nLPCE-3<\/th>\n<\/tr>\n<\/thead>\n
            \u0414\u0438\u0430\u043f\u0430\u0437\u043e\u043d \u0434\u043b\u0438\u043d \u0432\u043e\u043b\u043d<\/strong><\/td>\n380 \u2013 780 nm<\/td>\n380 \u2013 780 nm (optional 200 nm extension)<\/td>\n<\/tr>\n
            \u0422\u043e\u0447\u043d\u043e\u0441\u0442\u044c \u0434\u043b\u0438\u043d\u044b \u0432\u043e\u043b\u043d\u044b<\/strong><\/td>\n\u00b10.3 nm<\/td>\n\u00b10.3 nm<\/td>\n<\/tr>\n
            Spectral Resolution (FWHM)<\/strong><\/td>\n0.5 nm<\/td>\n0.4 nm<\/td>\n<\/tr>\n
            Stray Light<\/strong><\/td>\n<0.01%<\/td>\n<0.005%<\/td>\n<\/tr>\n
            CCD Array<\/strong><\/td>\n2048 pixels, CMOS<\/td>\n2048 pixels, back-thinned<\/td>\n<\/tr>\n
            Photometric Range<\/strong><\/td>\n0.001 \u2013 200,000 lm<\/td>\n0.0005 \u2013 100,000 lm<\/td>\n<\/tr>\n
            Sphere Diameters<\/strong><\/td>\n50 mm \u2013 2 m<\/td>\n50 mm \u2013 1 m<\/td>\n<\/tr>\n
            Auxiliary Lamp Correction<\/strong><\/td>\nYes (per CIE 84)<\/td>\nYes (per CIE 84)<\/td>\n<\/tr>\n
            Power Meter Accuracy<\/strong><\/td>\n0.2% RD + 0.1% RG<\/td>\n0.1% RD + 0.05% RG<\/td>\n<\/tr>\n
            \u0420\u0430\u0431\u043e\u0447\u0430\u044f \u0442\u0435\u043c\u043f\u0435\u0440\u0430\u0442\u0443\u0440\u0430<\/strong><\/td>\n15\u00b0C \u2013 35\u00b0C<\/td>\n10\u00b0C \u2013 40\u00b0C<\/td>\n<\/tr>\n
            Interface<\/strong><\/td>\nUSB, Ethernet<\/td>\nUSB, Ethernet, RS-232<\/td>\n<\/tr>\n
            \u0421\u043e\u043e\u0442\u0432\u0435\u0442\u0441\u0442\u0432\u0438\u0435 \u0441\u0442\u0430\u043d\u0434\u0430\u0440\u0442\u0430\u043c<\/strong><\/td>\nCIE 127, LM-79-19, Energy Star, IEC 62471<\/td>\nSame + FAA AC 150\/5345-53, ECE R119<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n
            \n

            8. Competitive Advantages in Independent Testing Laboratories and Scientific R&D<\/h3>\n

            In scientific research laboratories<\/strong>, the measurement chain is paramount. The LISUN LPCE-2 and LPCE-3 offer three unique advantages over competing integrating sphere systems:<\/p>\n

              \n
            1. \n

              Spatial Uniformity Correction:<\/strong> The system incorporates an iterative scattering correction algorithm that accounts for the bidirectional reflectance distribution function (BRDF) of the sphere coating. This reduces the spatial non-uniformity error from 2% (typical for untreated spheres) to <0.3%.<\/p>\n<\/li>\n

            2. \n

              Real-Time Self-Absorption Compensation:<\/strong> For large DUTs (e.g., 300 mm LED panels), the sphere\u2019s auxiliary lamp method measures the change in sphere multiplier (M) due to the presence of the DUT. The LPCE-2 software automatically applies this correction factor, eliminating the need for separate absorption measurements.<\/p>\n<\/li>\n

            3. \n

              Traceable Calibration Chain:<\/strong> The system is calibrated against a NIST-traceable spectral irradiance standard and a photometric calibration lamp (CIE Class L1). The uncertainty budget is fully documented for ISO\/IEC 17025 accreditation.<\/p>\n<\/li>\n<\/ol>\n

              For urban lighting design<\/strong> firms, the ability to provide a complete photometric file (IESNA LM-63) alongside spectral data from a single measurement streamlines the transition to spectral rendering in software.<\/p>\n

              \n

              \u0427\u0430\u0441\u0442\u043e \u0437\u0430\u0434\u0430\u0432\u0430\u0435\u043c\u044b\u0435 \u0432\u043e\u043f\u0440\u043e\u0441\u044b (FAQ)<\/h3>\n

              Q1: What is the difference between the LISUN LPCE-2 and LPCE-3 for LED testing?<\/strong>
              \nThe LPCE-3 features a back-thinned CCD array with lower stray light and improved UV sensitivity compared to the LPCE-2\u2019s standard CMOS array. The LPCE-3 is recommended for applications requiring high-accuracy colorimetric measurement (e.g., medical and display testing), while the LPCE-2 offers the best value for general-purpose LED lumen and CCT verification.<\/p>\n

              Q2: Can the LPCE-2 measure flicker or temporal light artifact (TLA) of LEDs?<\/strong>
              \nYes. The LPCE-2 includes an optional photodetector module (fast photodiode, 10 kHz bandwidth) that measures flux as a function of time. The software computes flicker index, percent flicker, and stroboscopic visibility measure (SVM) per IEEE 1789-2015.<\/p>\n

              Q3: How does the sphere size affect measurement of large automotive lamps?<\/strong>
              \nA larger sphere (e.g., 2-meter diameter for the LPCE-2) reduces self-absorption effects for large DUTs. However, for lamps with total flux < 5000 lm, a 300 mm sphere is often sufficient. The LPCE-3\u2019s software includes a port fraction calculator to guide the user in selecting the correct sphere geometry.<\/p>\n

              Q4: Is the LPCE-2 compatible with LED modules requiring heat sink plates?<\/strong>
              \nYes. The LPCE-2 can be ordered with a thermal base plate, allowing the DUT to be mounted on a temperature-controlled heat sink (range 25\u00b0C to 100\u00b0C). This is essential for measuring Tj-dependent parameters such as efficacy droop and color shift.<\/p>\n

              Q5: What data formats are exported for compliance with international standards?<\/strong>
              \nThe LPCE-2 and LPCE-3 software exports data in .XLSX, .CSV, .IES (LM-63), .LDT, and .CIE formats. It also generates a standardized test report compliant with LM-79-19, including spectral power distribution, chromaticity coordinates, and electrical parameters.<\/p>\n

              \n

              This technical article is intended for industry professionals seeking advanced metrological solutions for photometric and colorimetric characterization. For calibration certificates and specific application notes, consult the LISUN technical support team.<\/em><\/p>","protected":false},"excerpt":{"rendered":"

              Title: Advanced Ulbricht Sphere Applications in LED and Lighting Industries: Leveraging the LISUN LPCE-2 \/ LPCE-3 Spectroradiometer Integrating Sphere System for High-Precision Photometric, Colorimetric, and Radiometric Characterization Author: Technical Documentation Division, Photometric Metrology Group Date: October 2025 Introduction: The Ubiquity of the Ulbricht Sphere in Modern Photometry The Ulbricht sphere, an integrating sphere with a […]<\/p>\n","protected":false},"author":1,"featured_media":3432,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[772],"class_list":["post-8811","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blogs","tag-ulbricht-sphere"],"_links":{"self":[{"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/posts\/8811","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/comments?post=8811"}],"version-history":[{"count":1,"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/posts\/8811\/revisions"}],"predecessor-version":[{"id":8812,"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/posts\/8811\/revisions\/8812"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/media\/3432"}],"wp:attachment":[{"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/media?parent=8811"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/categories?post=8811"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ledtestsystem.com\/ru\/wp-json\/wp\/v2\/tags?post=8811"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}