Understanding The Differences Between Lumen And Candela For Emergency Vehicle LED Lights

When it comes to emergency vehicle LED lights or LED beacons, there are two ways to measure intensity: lumens or candelas. Another key criterion is SAE classification. But what is the difference between lumens and candela with respect to SAE classification for LED lights? 

D&R Electronics Co. Ltd., a reputed fleet vehicle solutions provider in Bolton, Ontario, offering lighting, police sirens, vehicle storage cabinets, and more for emergency vehicles, explores this question in detail.

What Is Lumen Output For Emergency LED Lights?

In the context of emergency vehicle LED lights, lumen output refers to the total light output. That is, it is the sum of all light energy emitted by the light source, irrespective of direction. 

What Is Candela For Emergency LED Lights?

Candela is fundamentally different from lumen output for emergency LED lights. This metric mainly measures the intensity of light along a specific direction. It is a measurement of the concentration of light along a particular direction or axis as it reaches the observer.

How Do Lumen And Candela Relate To SAE Rating?

As per SAE (Society of Automotive Engineers), a global professional association and standards development organization. Emergency vehicle LED lighting. is classified into three main SAE classifications: SAE 1, SAE 2, and SAE 3 for fleet vehicle operations. Class1 is the brightest and is used for emergency vehicles; Class 2 is used for Utility Vehicles, and Class 3 is meant for indoor or industrial low-speed use.

 
With this context, lumen output is not a sufficient measure for selecting LED lighting for emergency vehicles. Candela is the more accurate metric for selecting an SAE Class light. For instance, a light with 5000 lumen output and 180-degree diffusion might only produce 2000 candela, and all SAE Class 1 warning lights must have a candela rating above 8100 at a minimum; however, with advancement in technology and LED efficiency, it typically operates between 15,000 and 18,000 candela. Therefore, this 2000 candela LED light will fall under SAE Class 2 classification, which operates between 1981 candela and 8099 candela. Hence, the lumen rating is not the right metric in this case for selecting fleet-suitable LED lighting.

Conclusion

To conclude, lumens and candela are very different ways of measuring light output in LED lighting. For choosing SAE Class 1 warning lights, candela emerges as the better solution.

To learn more about emergency vehicle LED lights, LED beacons and other lighting solutions, reach out to us at D&R Electronics Co. Ltd. today. We are a leading fleet solution provider in North America, the Middle East, Europe, and Australia. We also offer police sirens, vehicle storage cabinets, powder distribution units and more. Contact us at 1-800-538-7338 for more information.

FAQs:

How to choose the SAE class for your vehicle fleet?

To choose the SAE class for your vehicle fleet, consider the maximum operating speed, regulatory jurisdiction and worst-case deployment scenario.

What is the Candela output for SAE class 3 warning lights?

For SAE class 3 warning lights, the Candela output should be below 1800 candela.