LM-79 Vertical Goniophotometer Testing System in Multi-Type Light Source Testing

Abstract
With the rapid development of lighting technology, various lighting products such as LED light sources, plant growth lights, and HID light sources have increasingly high requirements for the accuracy and comprehensiveness of optical parameter testing in the production, R&D, and quality inspection processes. The LM-79 Vertical Goniophotometer Testing System, as a professional optical parameter testing equipment, can meet the full-space optical parameter testing needs of different types of light sources. This paper takes the LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System as the research object, deeply analyzes its technical principles, testing capabilities, product characteristics, and applications in multi-type light source testing. It focuses on expounding the functional advantages of the system in automatically testing 3D luminous intensity distribution curves and the design features of customizable testing distances. Meanwhile, combined with specific technical parameter tables, it provides comprehensive equipment application references for relevant practitioners in the lighting industry.

1. Introduction
In the whole life cycle of lighting products, key optical parameters such as luminous intensity distribution, luminous flux, and luminous efficiency directly determine the lighting effect, energy consumption level, and use safety of the products. Different types of lighting products, such as LED lamps for indoor lighting, plant growth lights for plant cultivation, and street lamps and floodlights for outdoor lighting, have diverse requirements for the compatibility, testing accuracy, and testing range of testing equipment due to differences in application scenarios and design principles.

As a professional equipment that meets international mainstream testing standards, the LM-79 Vertical Goniophotometer Testing System can realize accurate testing of full-space optical parameters. The LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System, as a representative product of this type of equipment, is upgraded from the LSG-5000 and LSG-3000 in accordance with Clause 7.3.1 of the LM-79-19 standard. It not only fully meets a number of international and national standards such as LM-79-24, EN13032-1, and CIE S025, but also has core advantages such as automatically testing 3D luminous intensity distribution curves and customizable testing distances. It can be widely used in the testing of multi-type light sources including LED light sources, plant growth lights, HID light sources, indoor and outdoor lighting, street lamps, and floodlights, providing key technical support for R&D innovation and quality control in the lighting industry.

2. Technical Principles and Core Characteristics of LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System
2.1 Technical Principles
The LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System adopts a testing structure of “fixed lamp, moving probe”, and its core testing principle complies with the standards of IESNA (Illuminating Engineering Society of North America) and CIE (International Commission on Illumination). During the testing process, the tested lamp remains absolutely stationary. The near-field probe and the reflector move circularly around the lamp, while the far-field probe and the reflector rotate synchronously. This ensures that the probe can continuously and stably sense the light source signal of the lamp, thereby realizing the non-dead-angle collection of optical parameters in the full space (with a γ angle range of ±180° or 0~360°).

The system is equipped with a Japanese Mitsubishi servo motor and a German decoder, which provide high-precision drive support for the probe movement. The start and stop processes are stable without jitter. The angle accuracy can reach 0.05°, and the angle resolution is as high as 0.001°, which effectively avoids testing data deviations caused by mechanical movement errors. At the same time, the specially designed cross laser calibration device can quickly and accurately fix the position of the tested light source, further improving the stability of the testing benchmark and ensuring the consistency and reliability of each test data.

2.2 Core Characteristics
Wide Standard Compatibility: The LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System fully meets international and national standards such as LM-79-24 Photometric and Electrical Measurements of Solid-State Lighting Products, LM-79-19 Photometric and Electrical Measurements of Solid-State Lighting Products, EN13032-1 Clause 6.1.1.3 Lamps and Lighting – Measurement and Presentation of Photometric Data of Lamps and Luminaires – Part 1: Measurement and File Format, CIE-121 Photometric Testing of Luminaires and Distribution Photometry, and CIE S025 Testing Methods for LED Lamps, LED Luminaires and LED Modules. It also complies with regional standards such as SASO2902, IS16106, and GB (national standards), so the test data is recognized worldwide.

Comprehensive Parameter Testing Capability: The optical parameters that can be tested by the system include luminous intensity, luminous intensity distribution, zonal luminous flux, luminous efficiency, luminance distribution (optional), utilization factor, luminance limit curve, glare rating (UGR), maximum allowable distance-height ratio, is illuminance diagram, upward luminous flux, downward luminous flux, is illuminance curve, is luminous intensity curve, effective luminous angle, and EEI (Energy Efficiency Index). It can provide a comprehensive basis for evaluating the optical parameters of different types of light sources.
Flexible Customized Design: The testing distance can be personalized designed according to customer needs. Whether it is a small LED module or a large street lamp, the testing distance can be adjusted to adapt to the tested products of different sizes and powers, solving the problem of insufficient compatibility of traditional fixed-distance testing equipment with the tested lamps.

Expansibility of Spectral Radiation Testing: The system can be combined with a high-precision CCD spectral radiometer (such as the LPCE-2 High-Precision Rapid Spectral Radiometer & Integrating Sphere Testing System) to form an LSG-6000CCD spatial spectral radiation vertical goniophotometer, realizing the testing of spatial correlated color temperature distribution and other spatial spectral color parameter distributions. At the same time, the software and hardware both support the testing of PAR (Photosynthetically Active Radiation), PPF (Photosynthetic Photon Flux), and PPFD (Photosynthetic Photon Flux Density) spatial distributions for plant lighting, and can export files in IES/LDT format, which is suitable for the subsequent application of lighting design software (such as DiaLux).

Convenient Operation and Data Processing: The system communicates with the computer through RS-485/USB interfaces. The supporting Chinese and English software can run on mainstream operating systems such as Win7, Win8, Win10, and Win11, with a simple and intuitive operation interface. The test results can be saved in various formats such as CIE, IES, and LDT, facilitating the subsequent analysis and sharing of data and greatly improving the efficiency of testing work.

3. Application of LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System in Multi-Type Light Source Testing
3.1 LED Light Source Testing
Due to advantages such as small size, low energy consumption, and long service life, LED light sources are widely used in indoor lighting, display screens, automotive lighting, and other fields. In the testing of LED light sources, the 3D luminous intensity distribution curve is a key indicator for evaluating their lighting range and light spot uniformity. The LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System can automatically collect the luminous intensity data of LED light sources in the full space and generate accurate 3D luminous intensity distribution curves, helping R&D personnel optimize the arrangement of LED chips and the design of optical lenses to ensure that the light output of LED light sources meets the requirements of application scenarios.

For example, in the testing of indoor LED downlights, the system can test their downward luminous flux, is illuminance curve, and glare rating to determine whether the downlights have dark areas in the light spot or excessive glare. In the testing of LED display backlights, through luminance distribution testing, the uniformity of the backlight source can be evaluated to avoid the “water ripple” phenomenon of uneven brightness on the display screen. At the same time, the Class L constant-temperature photometric probe of the system (complying with DIN5032-6/CIE pub1. No. 69 standard, with f1′<1.5%) can accurately capture the weak luminous intensity changes of LED light sources, ensuring the accuracy of test data.

3.2 Plant Growth Light Testing
The core function of plant growth lights is to provide photosynthetically active radiation of specific wavelengths for plant growth. Their parameters such as PAR, PPF, and PPFD directly affect the photosynthetic efficiency of plants. The LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System (especially the LSG-6000CCD model) can realize accurate testing of PAR, PPF, and PPFD spatial distributions for plant lighting through software and hardware upgrades, generate spatial distribution maps, and help R&D personnel adjust the spectral distribution and luminous angle of the lamps to adapt to the lighting needs of different plants (such as leafy vegetables, flowers, and fruits) at different growth stages (germination stage, growth stage, flowering and fruiting stage).
For example, in the testing of plant lights for greenhouse tomato cultivation, the system can test the spatial distribution of PPFD at the crop canopy height to ensure that each tomato plant can obtain uniform photosynthetically active radiation, avoiding growth differences caused by uneven lighting. At the same time, by testing the radiation distribution of different wavelengths (such as 660nm red light and 450nm blue light), the spectral ratio of the plant lights can be optimized to improve the yield and quality of tomatoes. After the test, the system can export IES/LDT files to facilitate the layout design of the greenhouse lighting system.

3.3 HID Light Source Testing
HID (High-Intensity Discharge) lamps have the characteristics of high luminous efficiency and large luminous flux, and are often used in large venue lighting, road lighting, and other scenarios. HID light sources generate high temperatures during operation, and their luminous intensity distribution is greatly affected by the position of the arc tube and the design of the lamp reflector. The fixed design of the lamp ignition position of the LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System can avoid test result deviations caused by temperature fluctuations due to lamp movement. At the same time, the measurable power range of the system reaches up to 600V/10A (AC/DC), which can adapt to the testing of HID light sources with different powers (from tens of watts to thousands of watts).
In the testing of HID lighting for stadiums, the system can test the luminous intensity distribution, utilization factor, and maximum allowable distance-height ratio of the lamps, helping designers determine the installation height and spacing of the lamps to ensure that there are no lighting dead angles in the stadium and that the lighting uniformity and brightness meet the requirements of sports events. In the testing of HID street lamps, by testing the is illuminance diagram and upward luminous flux, the road lighting effect and light pollution of the street lamps (excessive upward luminous flux will cause light pollution) can be evaluated, providing data support for road lighting design.

3.4 Indoor and Outdoor Lighting, Street Lamp, and Floodlight Testing
The core requirement of indoor and outdoor lighting (such as shopping mall chandeliers and hotel downlights), street lamps, and floodlights is to achieve uniform lighting in specific areas and comply with relevant lighting standards (such as GB 50034 Standard for Lighting Design of Buildings and GB 7000.1 Luminaires – Part 1: General Requirements and Tests). The full-space testing capability and customizable testing distance design of the LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System can adapt to the testing of lamps of different sizes and installation scenarios.

For example, in the testing of large-size chandeliers in shopping malls, the system can customize the testing distance according to the installation height and lighting range of the chandeliers, test their is illuminance curve and glare rating, ensure uniform lighting and no glare in the shopping area of the mall, and improve the shopping experience of consumers. In the testing of highway street lamps, the system can test the luminous intensity distribution, effective luminous angle, and is illuminance diagram of the street lamps, evaluate the irradiation distance and road brightness uniformity of the street lamps, and ensure the safety of vehicle driving. In the testing of outdoor square floodlights, by testing the downward luminous flux and luminance limit curve, the strong light of the floodlights can be prevented from causing light interference to surrounding residents.

4. Model Parameters and Adaptable Scenarios of LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System
The LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System provides a variety of models to adapt to the tested lamps of different sizes and weights and meet diverse testing needs. The core parameters of each model are shown in the following table:

LISUN Model	Size of Tested Lamp (Diameter E * Thickness F)	Maximum Weight of Tested Lamp	Measurable Power (AC/DC)	Minimum Height of Darkroom	Core Adaptable Scenarios
LSG-6000/LSG-6000CCD (Standard Type)	max Φ1600*600mm	50kg	max 600V/10A	4.1m	Small and medium-sized LED lamps, plant growth lights, HID lamps
LSG-6000L/LSG-6000LCCD (Extra-Large Type)	max Φ2000*900mm	80kg	max 600V/10A	5.2m	Large street lamps, square floodlights, venue lighting lamps
LSG-6000B/LSG-6000BCCD (Large Type)	max Φ1800*800mm	60kg	max 600V/10A	4.7m	Medium-sized street lamps, large shopping mall chandeliers, industrial lighting lamps
LSG-6000S/LSG-6000SCCD (Small Type)	max Φ1200*500mm	40kg	max 600V/10A	3.0m	Small LED modules, indoor downlights, desktop plant lights

It can be seen from the table that whether it is a small indoor lamp (such as an LED downlight with a diameter of less than 1200mm) or an extra-large outdoor lamp (such as a square floodlight with a diameter of 2000mm), a suitable model can be found in the product series of the LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System. At the same time, all models support combination with a spectral radiometer to realize spectral parameter testing. For UV light sources (such as UVA, UVB, and UVC lamps), special photometric probes (PHOTO-UVA-A, PHOTO-UVB-A, PHOTO-UVC-A) can also be selected, with test wavelength ranges covering 320~400nm, 275~320nm, and 200~275nm respectively, further expanding the testing range of the system.

5. Conclusions 
As a professional full-space optical parameter testing equipment, the LISUN LSG-6000 LM-79 Vertical Goniophotometer Testing System provides a reliable technical solution for the testing of multi-type light sources including LED light sources, plant growth lights, HID light sources, indoor and outdoor lighting, street lamps, and floodlights through its high-precision testing structure of “fixed lamp, moving probe”, comprehensive standard compatibility, flexible customized design, and wide light source adaptability. Its function of automatically testing 3D luminous intensity distribution curves can intuitively present the light output characteristics of the light source; the customizable testing distance design solves the problem of testing adaptation for lamps of different sizes; and the combined application with a spectral radiometer realizes the integrated testing of optical parameters and spectral parameters, meeting the continuously upgraded testing needs of the lighting industry.

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