LED Lumen Meter: Application of High-Precision Spectroradiometer & Integrating Sphere System in Multi-Type Light Source Testing

Abstract
With the rapid development of the lighting industry, quality control of light source products has become increasingly crucial, and accurate testing of optical, color, and electrical parameters is the core link in measuring light source quality. The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter, as a high-precision spectroradiometer & integrating sphere system, is capable of conducting comprehensive tests on various light sources such as energy-saving lamps, fluorescent lamps, HID lamps (e.g., high-pressure sodium lamps and high-pressure mercury lamps), cold cathode fluorescent lamps, and LED lamps. The test results of this system strictly comply with a number of authoritative international and domestic photoelectric and colorimetric testing standards, including CIE177, CIE-13.3, CIE-84, ANSI-C78.377, GB/T 24824, IESNA-LM-63-2, Optical-Engineering-49-3-033602, (EU) 2019/2015, LM-80, LM-79-19, and LM-79-24. It provides reliable technical support for the design, production, improvement, and factory inspection of lighting products, effectively ensuring the quality stability and performance compliance rate of light source products.

1. Introduction
With the continuous innovation of LED technology, LED lamps, featuring high energy efficiency, long service life, and environmental friendliness, have been increasingly widely used in the lighting field. Meanwhile, traditional light sources such as energy-saving lamps, fluorescent lamps, and HID lamps still play an important role in specific scenarios. For any type of light source, its optical, color, and electrical parameters directly determine the lighting effect, energy consumption level, and service life. Therefore, accurate testing of these parameters has become a key demand for the development of the lighting industry.

The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter, as a professional testing equipment integrating a high-precision spectroradiometer and an integrating sphere system, can meet the testing needs of various light sources. Its test results comply with a number of international and domestic authoritative standards, providing a comprehensive and reliable testing solution for lighting enterprises. It is of great significance for improving the quality of lighting products and promoting technological progress in the lighting industry.

2. Testing Objects of the LED Lumen Meter
The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter has a wide testing range, covering major light source types in the current lighting market, as detailed below:
2.1 Energy-Saving Lamps
As a replacement for traditional incandescent lamps, energy-saving lamps have been widely used in household and commercial lighting due to their high luminous efficiency and long service life. This LED Lumen Meter can accurately test key parameters of energy-saving lamps, such as luminous flux, luminous efficiency, color temperature, and color rendering index, to determine whether they meet relevant standard requirements. This ensures that energy-saving lamps can achieve the expected lighting effect during use and avoids problems such as excessive energy consumption or shortened service life caused by substandard parameters.
2.2 Fluorescent Lamps
Fluorescent lamps are widely used in office lighting, industrial lighting, and other scenarios due to their low cost and stable luminous efficiency. The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter can test parameters of fluorescent lamps, including spectral power distribution, color coordinates, and peak wavelength. By analyzing these parameters, the luminous characteristics of fluorescent lamps can be understood, providing data support for the production quality control and performance improvement of fluorescent lamps, and ensuring the lighting stability of fluorescent lamps in different usage environments.
2.3 HID Lamps
HID lamps (High-Intensity Discharge Lamps), including high-pressure sodium lamps and high-pressure mercury lamps, are characterized by high brightness and high luminous efficiency, and are commonly used in large-area lighting scenarios such as road lighting and stadium lighting. Due to the complex working principle of HID lamps, their optical, color, and electrical parameters are affected by many factors, making testing more difficult. However, the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter, relying on advanced spectroradiometer technology and an integrating sphere system, can accurately test parameters of HID lamps such as luminous flux, color temperature, and color rendering index. Even under complex working conditions, it can provide reliable data for the quality inspection of HID lamps, ensuring the lighting safety and effectiveness of HID lamps in important places such as roads and stadiums.
2.4 Cold Cathode Fluorescent Lamps
Cold cathode fluorescent lamps have the advantages of long service life, low starting voltage, and uniform light emission, and are widely used in backlighting of liquid crystal displays, advertising light boxes, and other fields. This LED Lumen Meter can test parameters of cold cathode fluorescent lamps, such as luminous flux, color coordinates, and spectral characteristics. It helps manufacturers control the production quality of cold cathode fluorescent lamps, ensuring that they can provide stable and uniform light sources in application scenarios such as backlight displays, thereby improving the display effect.
2.5 LED Lamps
LED lamps are the mainstream products in the current lighting industry, and their quality directly affects the lighting effect and user experience. The quality of LED lamps must be comprehensively evaluated by testing their optical, color, and electrical parameters. The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter can conduct comprehensive tests on multiple parameters of LED lamps, including luminous flux, luminous efficiency, color coordinates, color temperature, color rendering index, voltage, current, and power. Through accurate measurement of these parameters, the performance of LED lamps can be fully evaluated, providing strong support for the design optimization, production quality control, and factory inspection of LED lamps, and helping enterprises produce high-quality LED lighting products.

3. Testing Principle and Core Technology of the LED Lumen Meter
3.1 Function of the Integrating Sphere System
The integrating sphere is one of the core components of the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter, and its main function is to achieve accurate measurement of the luminous flux of light sources. The inner wall of the integrating sphere is coated with a diffuse reflective material with high reflectivity. When the light emitted by the light source enters the integrating sphere, it undergoes multiple diffuse reflections inside the sphere, resulting in a uniform light intensity distribution on the inner wall of the integrating sphere. By installing a detector at a specific position on the inner wall of the integrating sphere, the uniform light intensity on the inner wall can be measured, and then the luminous flux of the light source can be calculated based on the characteristic parameters of the integrating sphere.

This testing method based on the integrating sphere can effectively avoid the impact of uneven light emission of the light source on the test results, ensuring the accuracy of luminous flux testing. At the same time, the design of the integrating sphere also takes into account the testing needs of light sources of different sizes and types. The size of the integrating sphere and the testing interface can be adjusted to meet the testing requirements of various light sources.

3.2 Technical Advantages of the High-Precision Spectroradiometer
The spectroradiometer is a key part of this LED Lumen Meter for realizing the testing of optical and color parameters. The high-precision spectroradiometer adopted by the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter has high spectral resolution and wavelength accuracy, and can accurately measure the spectral power distribution of the light source. By analyzing the spectral power distribution, color parameters of the light source such as color coordinates, color temperature, and color rendering index, as well as optical parameters such as luminous flux and luminous efficiency, can be calculated.
This spectroradiometer also has the characteristic of fast response, which can complete the measurement of the light source spectrum in a short time, improving the testing efficiency and meeting the needs of batch production testing in enterprises. In addition, the spectroradiometer has good stability, which can maintain the consistency of testing accuracy during long-term testing, ensuring the reliability of test data.

3.3 Overall Working Process of the System
The overall working process of the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter is as follows: Firstly, the light source to be tested is installed on the testing bracket of the integrating sphere, and the power supply is connected in accordance with the testing requirements. Then, the testing system is started, the light source begins to emit light, and the light enters the integrating sphere and undergoes multiple diffuse reflections. Next, the detector on the inner wall of the integrating sphere detects the uniform light intensity signal and transmits the signal to the spectroradiometer. The spectroradiometer performs spectral analysis on the optical signal to obtain the spectral power distribution of the light source. Finally, the system calculates the optical, color, and electrical parameters of the light source, such as luminous flux, luminous efficiency, color coordinates, color temperature, and color rendering index, based on the spectral power distribution and relevant standard algorithms, and presents the test results to the user in the form of a data report. The user can judge the quality of the light source based on the test results.

4. Compliance of the LED Lumen Meter with Testing Standards
The test results of the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter strictly comply with a number of authoritative international and domestic photoelectric and colorimetric testing standards, as detailed below:
4.1 International Standards
• CIE Standards: CIE177, CIE-13.3, CIE-84, and other CIE (International Commission on Illumination) standards are important international standards in the lighting field, which regulate the testing methods and technical requirements for the optical, color, and electrical parameters of light sources. This LED Lumen Meter is designed with testing processes and algorithms in accordance with the requirements of these standards, ensuring the accuracy and consistency of test results and complying with internationally accepted testing specifications.
• ANSI Standards: ANSI-C78.377 is a standard developed by the American National Standards Institute (ANSI) regarding the performance specifications of LED lamps, which specifies the testing methods and limits for parameters such as luminous flux, color temperature, and color rendering index of LED lamps. The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter can meet the testing requirements of this standard, providing test data support that complies with local standards for LED lighting products exported to the U.S. market.
• IESNA Standards: IESNA-LM-63-2, LM-80, LM-79-19, LM-79-24, and other IESNA (Illuminating Engineering Society of North America) standards are professional standards for light source testing. Among them, the LM-79 standard mainly specifies the testing methods for parameters such as luminous flux, luminous efficiency, and color parameters of LED products, while the LM-80 standard regulates the testing of luminous flux maintenance rate of LED light sources. This LED Lumen Meter fully complies with the requirements of these standards and can conduct comprehensive performance testing and life assessment testing of LED products.
• Other International Standards: Optical-Engineering-49-3-033602 is a literature standard on optical testing technology published by the International Society for Optical Engineering (SPIE), and (EU) 2019/2015 is a regulatory standard developed by the European Union regarding the eco-design requirements for lighting products. The test results of the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter comply with the requirements of these standards and regulations, helping enterprises ensure that their produced lighting products meet the access conditions of the international market.

4.2 National Standards
GB/T 24824 is a national standard of China, “Performance Requirements for LED Modules for General Lighting”, which clearly specifies the testing methods and performance requirements for parameters such as luminous flux, luminous efficiency, color temperature, and color rendering index of LED modules. The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter conducts testing in strict accordance with this standard, providing a testing solution that complies with national standards for domestic LED lighting enterprises in terms of product quality control and market access, ensuring that the quality of domestic LED lighting products meets the requirements specified by the state.

5. Test Data Example of the LED Lumen Meter
To more intuitively demonstrate the testing accuracy and data performance of the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter, the following takes the testing of a certain type of LED lamp as an example, and presents some test data in the table below:

Testing Parameter	Test Value	Standard Requirement (Refer to GB/T 24824)	Compliance with Standard
Luminous Flux (lm)	1250	≥1200	Yes
Luminous Efficiency (lm/W)	135	≥130	Yes
Color Temperature (K)	4500	4000-5000 (Cool White Light)	Yes
Color Rendering Index (Ra)	85	≥80	Yes
Color Coordinate (x)	0.375	0.3127±0.003 (Reference Target Value)	Yes
Color Coordinate (y)	0.385	0.3290±0.003 (Reference Target Value)	Yes
Input Power (W)	9.25	Rated Power 9W±5% (8.55-9.45W)	Yes
Input Voltage (V)	220.5	Rated Voltage 220V±10% (198-242V)	Yes
Input Current (A)	0.042	–	–

It can be seen from the above test data that under the testing of the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter, all the optical, color, and electrical parameters of this type of LED lamp comply with the requirements of the GB/T 24824 standard. This fully demonstrates the accurate testing capability of this LED Lumen Meter and its ability to provide reliable data for judging the quality of LED lamps.

6. Application Value of the LED Lumen Meter
6.1 Assisting Enterprises in Product Design and Improvement
In the design stage of lighting products, the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter can test light source samples of different design schemes. By comparing and analyzing the test data, it helps designers understand the impact of different design parameters on the optical, color, and electrical performance of the light source, thereby optimizing the product design scheme, improving key performance indicators of the product such as luminous efficiency and color rendering index, and designing lighting products that better meet market demands.
In the process of product improvement, this LED Lumen Meter can test the improved products to verify the effectiveness of the improvement measures. For example, after an enterprise improves the heat dissipation structure of an LED lamp, it can test the changes in parameters such as luminous flux, luminous efficiency, and color temperature of the LED lamp before and after the improvement to determine whether the improvement of the heat dissipation structure has a positive effect on the performance improvement of the LED lamp, providing data support for further product improvement.

6.2 Ensuring Enterprise Production Quality Control
In the production process of lighting products, the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter can be used as an important tool for production quality control to conduct sampling tests or 100% inspection on products on the production line. Through testing the optical, color, and electrical parameters of products, quality problems occurring in the production process, such as low luminous flux and excessive color temperature deviation, can be found in a timely manner. This allows production enterprises to adjust the production process and parameters in a timely manner, avoiding substandard products from entering the market and reducing the quality risks and cost losses of enterprises.

At the same time, the efficient testing capability of this LED Lumen Meter can meet the testing needs of enterprises for batch production, improve production efficiency, and ensure the smooth progress of the production plan.

6.3 Providing a Reliable Basis for Product Factory Inspection
Product factory inspection is the last barrier to ensure product quality. The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter can provide comprehensive and accurate test data for the factory inspection of lighting products. Only products that pass the testing of this LED Lumen Meter and meet the requirements of relevant standards can be delivered for sale. This not only protects the legitimate rights and interests of consumers, preventing them from purchasing substandard lighting products, but also enhances the brand image and market competitiveness of enterprises, winning the trust and recognition of consumers.

6.4 Promoting Technological Progress and Standardized Development of the Lighting Industry
The LISUN LPCE-2 (LMS-9000C) LED Lumen Meter complies with a number of international and domestic authoritative standards. Its wide application can promote lighting enterprises to carry out production and testing in accordance with unified standards, reduce product quality differences caused by inconsistent testing standards, and promote the standardized development of the lighting industry.

At the same time, the high-precision testing capability of this LED Lumen Meter can provide reliable test data support for technical research in the lighting industry, helping research institutions and enterprises carry out innovative research on lighting technology, promoting technological progress in the lighting industry, and facilitating the continuous emergence of high-efficiency, energy-saving, and environmentally friendly lighting products, thereby contributing to the achievement of the “dual carbon” goal.

7. Conclusion
As a professional testing equipment integrating a high-precision spectroradiometer and an integrating sphere system, the LISUN LPCE-2 (LMS-9000C) LED Lumen Meter has a wide range of testing objects, accurate testing capabilities, and test results that comply with a number of international and domestic standards. This LED Lumen Meter can not only conduct comprehensive optical, color, and electrical parameter testing on various light sources such as energy-saving lamps, fluorescent lamps, HID lamps, cold cathode fluorescent lamps, and LED lamps, providing a reliable basis for judging light source quality, but also plays an important role in product design and improvement, production quality control, and product factory inspection of enterprises. Meanwhile, it is of great significance for promoting technological progress and standardized development of the lighting industry.

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