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Measured Lumen? Luminaire Lumens? Delivered Lumens? Board Lumens?

By November 26, 2019 No Comments
Measured Lumen? Luminaire Lumens? Delivered Lumens? Board Lumens?

We were asked this week to clarify our performance figures on our website and data sheets:

At BSS LED we are a luminaire manufacturer and as such all the information we quote is based on luminaire lumens.

Measured Lumen? Luminaire Lumens? Delivered Lumens? Board Lumens? What does it really mean? is it important?

This means that we connect one of our luminaires to a 230volt calibrated power supply and measure the total lumens delivered from the product.

This measurement includes all electrical and optical losses from the luminaire.

We also use 3rdparties test labs such as the LIA Labs to measure our performance data.

Unless you are selling light engines, there is simply no purpose or benefit in quoting any other figure than Luminaire Lumens, it is simply misleading.

As you are not going to remove the light engine from the luminaire, the efficacy or performance of the light engine serves no purpose.

There is also the issue of maintained lumens after a set period of time and how LEDs degrade based on operating temperature and quality. This should be considered before making purchasing decisions by using actual data rather than theoretical modelling.

In September 2017 we wrote and article on lumen per watt claims with a clear explanation on electrical and mechanical losses:


It is also not all about luminaire efficacy, but you also need to consider the lumen distribution or how the light is distributed. It is easy to use optical lenses to concentrate a beam of light but that isn’t much use when you need good even uniformity.

There are some within the lighting industry who seek to mislead potential customers with exaggerated claims of efficacy without anything to substantiate their claims.

In summary:

  1. Only luminaire lumens really give you factual data
  2. Only an LDT file from an accredited body such as the LIA or other 3rdparty test house should be used.
  3. Long term luminaire maintenance data quoting figures such as L70 B10 to 50000 hours should be treated with caution and clarification sought as to warranty conditions and if lumen depreciation is covered

At BSS LED, we manufacture every product we sell in Manchester, we don’t rebrand or rebadge imported product and claim to be a British manufacturer. We offer a clear and simple 5-year warranty without ‘special clauses’ and we included a lumen depreciation warranty on all our products.

For more information us at info@bssled.com or call us on 0161 711 1911