Manufacturers often use labels like lumen, lux, and watt to indicate the performance of their explosion-proof LED light fixtures. However, you may find yourself scratching your head at these various terms and what they express about the brightness of the light fixture if you are a layman. 

Actually, these terms are related to the brightness of light fixtures in different aspects. Perception of the brightness of light fixtures varies from person to person, as it is based on individual visual experience. Let us examine the definitions and differences between these terms so that you can understand how to choose your ideal explosion-proof lighting.

Learn More: 5 Facts About Explosion-Proof LED Lighting

Lumen, Lux, and Watt: What Do They Mean?

1. Lumen

Lumen describes the total quantity of light emitted by an explosion-proof LED light fixture that you want to illuminate an area. However, please note that this metric measures the total output from all directions. Hence, the luminous flux measured by the lumen is not emitted evenly.

Many often mistakenly assume that illumination increases with a higher lumen output. But total light output from all directions is only partly perceivable by the human eye. Moreover, the light is emitted unevenly. As a result, many will perceive the brightness as remaining the same even when the lumen output increases significantly.

As light intensity is not even in all directions, manufacturers often use the term ‘candela’ to measure the luminous intensity. This term helps describe the total light emitted in one direction or specific solid angle. 

2. Lux

Lux is the unit of illuminance, referring to the total luminous flux on a surface. It can also be used to measure light intensity. For comparison, one lux equals one lumen per square metre (lm/m²). Lux levels are related to the distance between the lit object and the light source. The further the item is from the light source, the lower the lux level.

For example, there is one lux at one metre (distance between the illuminated item and the light source) if one candela of light falls on an object. That figure drops to 0.25 lux at 2 metres. Both lux and candela can be used to measure light intensity. However, the difference is that the candela level does not change with distance, whereas lux does. 

3. Watt

Watt measures the total wattage (power or energy) consumed by a light source when emitting light. When purchasing explosion-proof lighting, this is the most common term used to describe the ‘brightness’ of the light fixture. 

However, please note that watt cannot indicate the light output directly. Instead, watt and lumen are used together in a term – lm/w – to connect the light output with wattage consumption to express the efficiency of the light source. Lm/w refers to the ratio between the energy consumption of the light source and total light output.

In summary, the descriptions of lumen, candela, lux, and watt are as follows:

While lumen better describes light output than watt level, as it indicates the actual brightness of a light fixture, we recommend using lm/w as a metric to choose your explosion-proof LED light fixtures accurately. After all, as a business owner, what you desire is the most cost-effective explosion-proof lighting. 

 If you seek reliable and cost-effective explosion-proof lighting, look no further than Supermec. We carry an extensive selection of explosion-proof LED light fixtures at attractive prices. Contact our friendly team today if you require help selecting the ideal explosion-proof lighting for your hazardous work environment.