How do we ensure SSL product quality? How can we be confident that product test results are reliable?
Lifetime testing is particularly relevant for policy makers and market surveillance authorities who are concerned with verifying lifetime claims on packaging. However, determining the lifetime of LED products can be challenging and costly. The SSL Annex is working to understand LED product lifetime to support government measurement, verification and enforcement programmes.
A report was prepared and published that looks across the body of literature on lifetime definitions for LEDs and LED products. The report looks at failure mechanisms, accelerated life test and test methods for estimating lifetime, and provides some recommendations. Click on the button below to learn about the report and download a copy.
The SSL Annex also works to assist the lighting metrology community and improve the comparability and accuracy of LED product testing. Over the last decade, the SSL Annex has been conducting international interlaboratory comparisons to improve measurement of SSL products globally.
In 2014, the SSL Annex published a report (2013 IC Final Report) that compared the measurement accuracy of 110 laboratories worldwide testing Light Emitting Diode (LED) lamps and luminaires. That report is intended to help governments and manufacturers ensure that new LED products sold to consumers and companies are of high quality and meet the claimed performance. That work also sought to establish a common proficiency test method for accreditation programmes.
In 2021, the SSL Annex published a report (2017 IC Final Report) that compared goniophotometric measurements of LED luminaires and narrow-beam LED lamps. IC 2017 was designed to be in compliance with ISO/IEC 17043 to serve as a proficiency test for SSL testing accreditation programmes that recognise this comparison. IC 2017 used CIE S 025/E:2015, Test Method for LED Lamps, LED Luminaires and LED Modules as the test method for LED performance measurement.
Other information on Testing and Standards
In 2015, The Commission Internationale de l’Eclairage (CIE) published a new International Standard (CIE S 025/E:2015) called “Test Method for LED Lamps, LED Luminaires and LED Modules”. This standard was developed to be used by regulators and accreditation bodies around the world to harmonise the testing and accreditation of LED products. The SSL Annex conducted a study of this standard, including looking at the coverage of products, the performance metrics measured, the equipment covered and the requirements for testing.
This report prepared by the SSL Annex is titled “Application Study of CIE S 025/E:2015” and it evaluates the international standard for use as a standard by accreditation bodies, government policy makers and other key stakeholders as the basis for measuring quality and performance aspects of LED lighting products and equipment.
CIE S 025/E:2015 specifies the requirements for measurement of electrical, photometric, and colorimetric quantities of LED lamps, LED modules and LED luminaires, for operation with AC or DC supply voltages, possibly with associated LED control gear. LED light engines are assimilated to LED modules and handled accordingly. Photometric and colorimetric quantities covered in this standard include total luminous flux, luminous efficacy, partial luminous flux, luminous intensity distribution, centre-beam intensity, luminance and luminance distribution, chromaticity coordinates, correlated colour temperature (CCT), colour rendering index (CRI) and angular colour uniformity.
The lighting laboratory measurement instruments that are covered by CIE S 025/E:2015 include: sphere-photometer, sphere-spectroradiometer, goniophotometer, gonio-spectroradiometer and luminance meter. The following lighting laboratory measurement instruments are also accepted for use with CIE S 025/E:2015 as long as equivalent results are demonstrated. In other words, these measurement instruments are acceptable if they are demonstrated to produce results equivalent to those of a conventional integrating sphere system or conventional (i.e., far-field) goniophotometer system: integrating hemisphere, near-field goniophotometer and imaging luminance measurement device (ILMD).
This report is a supporting document to the SSL Annex’s Interlaboratory Comparison 2017 (IC 2017) which was launched on 30 June 2017. IC 2017 is using CIE S 025/E:2015 as the test method for testing the lamp and luminaires in this interlaboratory comparison.
CLICK HERE to download the Application of CIE S 025/E Report