LED LM-79 Test Report: Authoritative "Pass" for Global Market Access & GTG’s Professional Services

In the LED lighting industry, over 85% of international buyers regard the LM-79 test report as a mandatory indicator for supply chain access. It has become the most authoritative "health certificate" for product photoelectric performance.

I. LM-79 Test Report: Authoritative "ID Card" for LED Product Performance

LM-79 is an authoritative test standard issued by the Illuminating Engineering Society (IES), fully titled Electrical and Photometric Measurements of Solid-State Lighting Products. This report is not an ordinary test document but a standardized verification basis for the photoelectric performance of LED luminaires and light sources, directly determining whether products can enter North American and other high-end international markets.

For LED manufacturers, the LM-79 test report is a necessary foundation for international certifications such as Energy Star, DLC, and CEC. Through rigorous testing methods, it provides customers with true product performance data, serving as a key credential for manufacturers to prove product compliance and performance superiority.

II. Core Value & Applicable Product Scope of LM-79 Test

Core Value of LM-79 Test Report

The core value of the LM-79 test report is reflected in three aspects:

1. Prerequisite for Market Access: Mandatory for certifications like Energy Star and DLC; products without the report cannot enter mainstream North American markets.
2. Basis for Performance Verification: Provides impartial third-party data to verify manufacturers’ claimed photoelectric parameters, enhancing buyer confidence.
3. Guide for R&D Optimization: Offers precise measurement data to guide the optimization of product photoelectric design.

Applicable Product Scope

The scope covers a wide range of products:

• LED luminaires (e.g., downlights, panel lights, street lights);
• Integrated LED bulbs and OLED bulbs;
• Non-integrated LED bulbs with external drivers;
• LED light engines.

Important Note: The standard explicitly excludes SSL products requiring external heat sinks, components such as LED packages or arrays, and luminaire housings that do not provide light sources.

III. Technical Requirements & Key Parameters of LM-79 Test

Strictly Controlled Test Environment

To ensure data accuracy, LM-79 testing has strict environmental requirements:

• Ambient temperature: 25℃±1.2℃;
• Humidity range: 10%-65%;
• Airflow velocity: No more than 0.2m/s.

Steady-State Determination Standard

Before testing, the product must reach a steady state:

• Monitor for at least 30 minutes;
• Obtain 3 photometric and electrical power readings within 20 minutes;
• The difference between the maximum and minimum values divided by the current point value must be less than 0.5%.

Key Measurement Parameters

Optical Parameters:

• Total luminous flux (lumens);
• Luminous efficacy (lm/W);
• Luminous intensity distribution;
• Chromaticity coordinates, correlated color temperature (CCT), color rendering index (CRI).

Electrical Parameters:

• RMS AC voltage and current;
• AC active power;
• Power factor;
• Total harmonic current distortion.

IV. Major Updates of 2024 New Standard: Detailed Interpretation of ANSI/IES LM-79-24

In 2024, ANSI and IES jointly released the LM-79-24 standard, replacing the previous LM-79-19 version. Key updates include:

1. Added Concept of Beam Center: Clearly defined as "The point in a light source from which the inverse-square law operates most closely in the direction of maximum intensity."
2. Changed Test Circuit Capacitance: Adjusted from ≤1.5 nF to ≤2.0 nF.
3. Simplified Harmonic Acquisition Requirements: Removed the requirement that the harmonic acquisition order of 1 MHz instruments must be at least 2 to 100; unified the requirement for all instruments to 2 to 50.
4. Added Test Principle Explanation: Included the test principle description of Integrated Angular Measurements for light distribution.
5. Deleted Annex Content: Removed descriptions of "Airflow Considerations For Testing SSL Products" and "Power Supply Resistance And Inductance Interval" from Annex.

V. Comprehensive Interpretation of LM-79 Test Process

The complete test process includes:

1. Sample Preparation & Stabilization: Preheat the sample in the test environment until it reaches a steady state.
2. Test Equipment Calibration: Conduct measurements using a calibrated integrating sphere or goniophotometer system.
3. Photoelectric Parameter Measurement: Sequentially measure luminous flux, luminous efficacy, chromaticity parameters, etc.
4. Data Recording & Analysis: Record and analyze data in strict accordance with standard requirements.
5. Report Generation & Review: Generate a detailed test report containing all necessary information.

Test Method Description:

• Integrating Sphere System: Suitable for measuring parameters such as total luminous flux and color characteristics.
• Goniophotometer: Used to measure luminous intensity distribution, beam angle, etc.

VI. LM-79 Test Service Advantages of GTG Testing Group

1. Professional Testing Capabilities

GTG Testing Group’s laboratory is equipped with advanced equipment such as high-precision integrating sphere systems, goniophotometers, and spectrophotometers, ensuring accurate and reliable test data. Our technical team deeply understands LM-79 standard requirements and provides compliant testing services for various LED luminaires.

2. Full-Process Service Support

We offer one-stop services from pre-test consultation, test plan formulation, test execution to report interpretation. Our experts provide professional advice based on your product characteristics and market goals, helping you efficiently complete the test process.

3. Efficiency & Cost Optimization

Through rational test plan management and sample planning, we help customers optimize resource utilization and reduce overall test costs while ensuring test quality. For customers in urgent need of data, we also provide phased test data to support product development progress.

In the increasingly competitive LED lighting market, the LM-79 test report has evolved from a "bonus item" to a "necessity." It is not only an authoritative proof of product photoelectric performance but also a reflection of enterprise technical strength and brand reputation. Choosing an experienced testing partner ensures an efficient and compliant test process, giving your products a competitive edge in the market.

With profound technical accumulation and rich project experience, GTG Testing Group has successfully helped numerous LED enterprises complete LM-79 testing, paving the way for their products to enter the global market.