Top Photometric Standards for LED Lighting
Explore essential photometric standards for LED lighting, ensuring consistent performance, compliance, and energy savings in commercial applications.
Photometric standards ensure LED lighting delivers consistent performance, meets regulations, and supports energy savings. These standards help businesses choose reliable products, avoid compliance issues, and maximize efficiency. Key standards include:
- IES LM-79: Measures initial performance (e.g., luminous flux, color temperature, and power consumption) of complete LED systems.
- IES LM-80 & TM-21: Assess and predict LED lifespan and lumen maintenance.
- ANSI C78.377: Ensures color consistency for indoor lighting.
- IES LM-85: Focuses on high-power LED arrays, addressing thermal management for industrial use.
- CIE S 025: Provides global testing protocols for LED lamps, modules, and luminaires.
These guidelines simplify product comparisons, ensure compliance, and enhance long-term reliability in commercial and industrial applications.
Testing LED Intensity with IES LM-75 and LM-80 Go-R5000 Goniometer - LISUN
1. IES LM-79: Electrical and Photometric Measurements of Solid-State Lighting Products
The IES LM-79 standard sets the gold standard for testing the electrical and photometric performance of solid-state lighting products in the United States. Developed by the Illuminating Engineering Society of North America (IESNA), it outlines how manufacturers should measure the performance of complete LED systems. This includes luminaires, integrated and non-integrated LED lamps, as well as LED light engines with their drivers and related hardware. The most recent version, ANSI/IES LM-79-19, was updated in 2020.
What LM-79 Measures
LM-79 provides a detailed framework for evaluating both optical and electrical characteristics. On the optical side, it measures key metrics such as luminous flux, luminous efficacy, luminous intensity, correlated color temperature (CCT), color rendering index (CRI), and chromaticity coordinates. For electrical performance, it assesses parameters like AC/DC voltage, input power, current draw, power factor, and total harmonic distortion (THD). This comprehensive data ensures a clear understanding of how an LED product performs under specific conditions.
Why It’s Important for Commercial Spaces
By standardizing testing methods, LM-79 makes it easier to compare LED products across different brands and models. The controlled laboratory conditions used in LM-79 testing ensure that the reported data closely mirrors real-world performance. This consistency is vital for commercial and industrial spaces, such as warehouses, offices, manufacturing plants, and retail stores.
For businesses looking to upgrade their lighting systems, LM-79 data serves as a critical tool. It helps decision-makers choose LED products that provide reliable light output, energy efficiency, and overall quality.
2. IES LM-80 and TM-21: Lumen Maintenance and Lifetime Projections
IES LM-80 is a standard approved by the Department of Energy (DOE) that measures how well LED light sources maintain their brightness over time. By testing LEDs in controlled conditions, LM-80 delivers critical data on lumen maintenance, which lays the groundwork for understanding how LEDs perform in the long run.
TM-21 takes this a step further by using mathematical modeling to predict the lifespan of LEDs based on LM-80 test results. This method allows for lifespan projections without waiting for LEDs to age naturally, saving both time and resources.
Together, these standards are vital for managing lighting systems in commercial and industrial settings. They provide facility managers and engineers with insights into how factors like temperature changes can impact LED performance. This ensures that lifespan projections align more closely with actual operating conditions. The combination of these standards highlights the importance of accurate testing and forecasting for reliable, long-term LED performance.
3. ANSI C78.377: Chromaticity Specifications for Solid-State Lighting
ANSI C78.377 outlines the recommended chromaticity ranges for solid-state lighting (SSL) products used in general lighting, focusing on maintaining color consistency. This standard is particularly important for indoor lighting in commercial spaces. It specifically addresses white light chromaticities and excludes applications like outdoor lighting or tinted indoor lighting.
By following ANSI C78.377, manufacturers can ensure that LED products provide uniform color temperatures and consistent quality across various fixtures. This consistency eliminates noticeable color variations, which is crucial for maintaining a cohesive appearance in commercial environments. It also allows facility managers and lighting designers to better communicate and plan for lighting performance.
The standard applies to LED-based SSL products that include control electronics and heat sinks, designed for either AC or DC power. It covers both standalone fixtures and integrated LED lamps.
In large commercial settings, the advantages of compliance with ANSI C78.377 are clear. Uniform light quality across multiple fixtures creates a seamless visual experience, while consistent chromaticity supports more precise photometric evaluations down the line.
4. IES LM-85: High-Power LED Measurement
IES LM-85 outlines the testing methods for high-power LED arrays, particularly in industrial and warehouse settings where heat and high light output demand precise measurement techniques. This standard is especially important for LEDs that generate significant heat, as improper handling can lead to inaccurate results.
A major focus of the standard is thermal management during testing. High-power LEDs often experience large temperature fluctuations, which can directly affect their photometric performance. To ensure accurate results, careful control and monitoring of temperature are essential throughout the testing process.
Common challenges include managing heat dissipation, dealing with variations in current density, and using specialized mounting setups. For instance, high-power LEDs in warehouse fixtures often operate above 1 ampere, which can influence both their light output and color consistency.
The standard also emphasizes the importance of stabilization periods before taking measurements. High-power LEDs typically require longer warm-up times compared to standard LEDs to reach thermal equilibrium. These extended stabilization protocols ensure that the data reflects actual operating conditions rather than the performance during initial startup. This is vital for industrial environments, where precise and reliable performance data is critical.
For industrial applications, adhering to IES LM-85 ensures that photometric data accurately reflects how high-power LED arrays will perform under real-world conditions. This is especially important for warehouse lighting, where fixtures often operate for more than 12 hours a day, or in manufacturing facilities where consistent lighting is essential for maintaining quality control.
The standard also addresses array-level testing for fixtures with series or parallel configurations, providing realistic performance data that can guide decisions on lighting upgrades and energy efficiency improvements.
Testing under IES LM-85 requires specialized equipment designed to handle the higher power loads and heat generated by these LEDs. This includes integrating spheres with advanced thermal management capabilities and power supplies with precise current regulation. These tools ensure stable and consistent measurements, even under demanding conditions.
5. CIE S 025: International Test Method for LED Lamps, Luminaires, and Modules
CIE S 025 serves as a global standard for evaluating the performance of LED lighting products. It establishes precise protocols for photometric and colorimetric measurements of LED lamps, modules, and luminaires, ensuring that performance data remains consistent across laboratories worldwide. By normalizing testing conditions, this standard minimizes discrepancies between facilities, so an LED tested in one country delivers comparable results in another, all within defined uncertainty limits.
One of the standout features of CIE S 025 is its comprehensive measurement framework. It outlines methods for assessing a broad range of performance metrics, including:
- Total luminous flux
- Luminous efficacy
- Partial luminous flux
- Luminous intensity distribution
- Center-beam intensity
- Luminance and its distribution
- Chromaticity coordinates
- Correlated color temperature (CCT)
- Color rendering index (CRI)
- Angular color uniformity
This level of detail is especially beneficial in commercial and industrial applications, where decision-makers rely on standardized data to compare LED products with confidence.
The reliability of the CIE S 025 standard is reinforced through proficiency tests conducted across multiple laboratories. These tests consistently validate measurements of key parameters like total luminous flux, luminous efficacy, and chromaticity. Professor Georges Zissis, Chair of the IEA 4E SSL Annex Management Committee, emphasized the importance of these findings in advancing lighting metrology, particularly for labs using goniophotometers. Dr. Yoshi Ohno from the National Institute of Standards and Technology noted:
"It was very interesting to review the data from all the participants, to find how the large variations were caused in some cases and where the standard was not followed correctly."
CIE S 025 also plays a critical role in compliance testing for LED performance, aligning with the requirements set by IEC/TC 34 "Lamps and related equipment." This ensures LED products meet international performance benchmarks.
Another key advantage of the standard is its adaptability to various goniophotometer configurations. This flexibility allows laboratories to achieve consistent results regardless of their specific testing setups.
For manufacturers, adhering to CIE S 025 simplifies entry into global markets by demonstrating compliance with internationally recognized testing protocols. For end users, the standardized performance data supports informed purchasing decisions and effective lighting design.
It’s worth noting that CIE S 025 focuses exclusively on LED lamps, modules, and luminaires. It does not cover LED packages or OLED-based products.
6. Luminate Lighting Group's Expertise in Photometric Standards Integration
Luminate Lighting Group incorporates photometric standards into every LED lighting project, treating these standards as the foundation for precise planning and fixture selection.
The process begins with a thorough planning phase, where the team evaluates client objectives and the unique characteristics of the space. This includes analyzing the architectural layout and electrical infrastructure. Using this information, they create detailed photometric layouts that simulate how light will be distributed, its intensity, and uniformity. These layouts ensure that the lighting design adheres to both industry standards and local regulations.
During the specification phase, Luminate Lighting Group recommends high-performance LED fixtures paired with advanced controls like dimming, occupancy sensors, and daylight harvesting systems. These features not only enhance performance but also improve energy efficiency. Their designs comply with major U.S. energy codes, streamlining the permitting process and often qualifying projects for rebates or tax incentives.
Photometric studies are a cornerstone of their approach. These studies help optimize energy use by determining the ideal light levels and guiding fixture choices. They also ensure compliance with local requirements, including measures to reduce light pollution and trespass. For retrofitting projects, photometric studies can lead to significant cost savings while maintaining strict regulatory compliance.
The results speak for themselves. By aligning with photometric standards, Luminate Lighting Group delivers reliable, high-performing solutions. For example, industrial clients transitioning from older technologies like HPS or CFL often see a 50% or greater reduction in fixture counts while extending fixture lifespans by up to 10 times - all without compromising light quality. This approach not only enhances efficiency but also ensures long-term value.
Comparison Table
Here's a breakdown of key photometric standards, designed to help lighting professionals choose the right testing method for their needs. Each standard focuses on specific aspects of LED performance, ensuring precise evaluation for various applications.
| Standard | Measurement Focus | Applicable Products | Parameters Measured | Test Duration | Primary Use Case |
|---|---|---|---|---|---|
| IES LM-79 | Overall performance of complete LED luminaires | Complete LED luminaires | Total luminous flux, luminous efficacy, chromaticity, electrical power, CCT, CRI, luminous intensity distributions | Single-point test | Establishes baseline performance data at initial use |
| IES LM-80 | Lumen maintenance of LED packages, arrays, and modules | LED packages, arrays, and modules | Lumen maintenance over time at specified intervals and temperatures | 6,000 to 10,000 hours | Predicts long-term reliability |
| ANSI C78.377 | Color consistency specifications | SSL products for general lighting | Chromaticity coordinates, CCT ranges | Single-point test | Ensures consistent color quality across fixtures |
| IES LM-85 | High-power LED array performance | High-power LED arrays and modules | Thermal management, luminous flux, electrical characteristics | Extended stabilization periods | Designed for industrial and warehouse applications |
| CIE S 025 | International LED performance evaluation | LED lamps, luminaires, and modules | Luminous flux, efficacy, chromaticity, CRI, luminance distribution | Single-point test | Supports global market compliance and standardization |
The table underscores the unique yet complementary roles of IES LM-79 and IES LM-80. While LM-79 focuses on capturing the initial electrical and photometric performance of LED luminaires, LM-80 provides insights into long-term reliability by testing lumen maintenance over extended periods (6,000 to 10,000 hours). Together, these standards provide a comprehensive framework for evaluating both short-term performance and long-term durability, guiding informed decisions in lighting design and application.
Conclusion
Photometric standards are the backbone of successful LED lighting projects. By adhering to these standards, lighting systems can maintain consistent performance, meet energy efficiency goals, and comply with local building regulations. Skipping standards like IES LM-79, LM-80, and ANSI C78.377 can leave businesses with lighting systems that underperform or fail to meet compliance requirements - a costly mistake no one wants to make.
Adopting these standards isn’t just about compliance; it’s a smart financial move. Proper photometric testing and adherence to these guidelines can lead to significant energy savings, especially when transitioning from older lighting systems to LED technology. These savings aren’t just theoretical - they directly impact operating costs, making them a win for your bottom line.
With over 40 years of experience, Luminate Lighting Group brings deep expertise in navigating complex photometric requirements. Their services include lighting assessments, energy audits, and detailed photometric evaluations, ensuring optimal brightness, uniformity, and compliance across various facilities. From design to installation and post-project testing, their turnkey solutions cover every stage of the process.
"The Luminate team retrofitted the lighting in a few of our commercial properties and I couldn't be more pleased with the quality of the work, the value they provided and the level of service that they provided. I can definitely recommend their work." - C. Bennett, Building Owner
For businesses considering LED lighting upgrades, the journey begins with a comprehensive lighting audit. This step pinpoints inefficiencies and compares current light levels against established standards, paving the way for customized solutions that enhance both performance and energy efficiency. When paired with professional installation and ongoing system checks, these measures ensure that your LED lighting investment delivers on its promises - meeting all necessary standards while maximizing energy savings.
FAQs
What role do photometric standards like IES LM-79 and LM-80 play in ensuring the performance and reliability of LED lighting?
Photometric standards like IES LM-79 and LM-80 play a key role in ensuring the quality and dependability of LED lighting systems. LM-79 is all about measuring LED performance - things like light output and color consistency - at a specific moment. On the other hand, LM-80 focuses on how well LEDs retain their brightness over time, giving insight into their long-term reliability.
By following these standards, manufacturers can produce LED lighting that is both energy-efficient and consistent in performance. This is especially critical in commercial and industrial environments, where dependable lighting directly impacts safety, productivity, and compliance with energy regulations.
Why is following ANSI C78.377 important for maintaining color consistency in commercial indoor lighting?
Adhering to ANSI C78.377 plays a key role in maintaining consistent color temperature and hue across LED lighting systems. This standard ensures uniform lighting quality, which helps create visually harmonious environments - an important factor for boosting productivity and comfort in commercial settings.
By aligning with this guideline, businesses can deliver dependable color performance, minimize variations in lighting appearance, and meet industry standards for professional indoor lighting solutions.
What is CIE S 025, and how does it support global standardization for LED lighting?
What Is CIE S 025?
CIE S 025 is an international standard outlining methods to test the photometric and colorimetric performance of LED lamps, luminaires, and modules. It provides a unified framework to ensure LED products are measured accurately and consistently, no matter where they're tested.
This standard is essential for manufacturers and regulators to verify product quality, ensure compatibility, and meet compliance requirements globally. By establishing clear guidelines, it helps build trust across the LED lighting industry and simplifies adherence to international standards.
