Jeff Hulett, Vektrex CTO, narrates this three-part webinar series on how to improve your LED light measurements.
Summary: Key Points
Improving LED light measurements requires a multi-faceted approach. The three components that Hulett focuses on in this series are power, accuracy, and repeatability. Watch the webinar summary video below to see the highlights from all three parts of the series.
Part One: Power
Sustained power is the foundation for LED light measurement. As LED devices including COB, array, luminaires, emitters, and others are moving to higher power levels, understanding the power limitations of current sources and source measure units (SMU) is critical. Many current sources, Keithley included, advertize 1000W power but that doesn’t mean that 1000W of sustained power is possible.
In this first segment of the webinar series, Hulett will teach you how to identify current source power limitations that may negatively impact your LED light measurements.
Read more about part one here.
Part Two: Accuracy
Once you have a current source that can use the three key measurement methods specified in LM-85, DC, Single Pulse, and Continuous Pulse, the question becomes: which method will yield the most accurate measurements?
Vektrex engineers conducted an L-I sweep with the Osram LY W5SM-GZJX-46-0-400-R18-Z Yellow LED using each of the three test methods. Comparing the luminous flux output across each method shows that there is a significant drop in luminous flux output when using Single Pulse or DC as compared to Continuous Pulse.
In this webinar, Hulett discusses the pros and cons associated with each test method and explains why LEDs experience a loss in luminous flux when DC and Single Pulse method are used. He also teaches how to use Continuous Pulse effectively.
Read more about part two here.
Part Three: Repeatability
The final segment of this webinar series discusses which factors must be controlled for optimal repeatability. Hulett gives examples of what to look for (and what to avoid) in your test and measurement equipment.
In this webinar, you’ll learn the differences in spectrometer light capture when using DC, Single Pulse, and Continuous Pulse measurement methods. LED light measurement is reliant on timing stability, especially when using DC or Single Pulse, so it’s important to use a current source with precise triggering. With Continuous Pulse, it’s critical to use a current source with minimized jitter to achieve highly repeatable measurements.
Read more about part three here.