Lux is the unit of illuminance. You must have heard of the lumen as the unit of light. Here, lux is slightly different. Lux is basically the measurement of lumens per square meter. It holds high importance in photometry as it can be used to decide how much light you need for a specific application. When we talk about the brightness or intensity of light, we often talk about foot candles or lux. However, foot-candle is used rarely these days in the industry because it is a non-SI unit. However, lux is a SI unit that is why it is used widely in the lighting industry. At times, it may be a little complicated to understand lux in terms of the lighting industry. What exactly lux is it? And how much lux do you need to get specific brightness? This post gives the introduction of lux along with its use in terms to understand lighting requirements.
What is Lux?
As per the calculation, 1 Lux= 0.0929 Foot Candles, conversely, 1-Foot Candle= 10.764 Lux and Lux= Lumen/m2.
In the lighting industry, lux is used as standardized merit of human visual brightness perception. Light efficiency is measured as lumens/watt while manufacturing or selecting a light source. Lumens is directly proportional to the lux; therefore, luminosity is directly proportional to the light intensity. The brightness of light in proportion to human eye perception gradually increases with the rise in lux level.
The intensity of light sensed by human eyes varies according to the intensity of light waves hitting the wall or floor. For example: If a bulb or light fixture is installed in a small enclosed room, there is less area available for the light wave to travel or transmit, therefore the intensity of light hitting the wall is higher. This is why in a small room, human eyes can sense higher light intensity. On the other hand, if the same bulb is installed in a larger room. The light wave can travel a long distance and eventually the intensity of the lightwave hitting the wall decreases. Therefore, in a large room, the luminance sensed by the human eye is less.
Due to factors like availability of natural light, exposure, type of light fixture used, etc Lux becomes an important consideration when selecting light for your facility. It helps in calculating the amount of light required for a specific type of area.
In order to measure lux, a device named lux meter is utilized. However, for specific applications, the lux level is standardized.
Let us discuss how much lux or light you require for applications.
Recommended Lux Level for your Light Requirements
The light requirements are decided for specific areas according to light photometric tests. However, the Occupational Safety and Health Administration (OSHA) states a few specific lighting requirements guidelines. By considering the brightness requirements of various functioning places without harming human eyesight, OSHA has stated the following lux levels for specific places.
- A light requirement for:
- First-aid stations, offices, and infirmaries= 30-foot candles= 322.92 lux.
- General shops and commercial buildings: 10-foot candles=107.64 lux.
- Construction sites: 5 foot candles= 53.82 lux.
- Warehouses, corridor, walkways, indoor walk spaces= 5-foot candles= 53.82 lux
- Tunnels, subways, underground workplaces (for stable applications) = 5 foot candles= 53.82 lux.
- Tunnels, subways, underground workplaces (for construction and maintenance activity) = 10 foot candles=107.64 lux.
- Field maintenance areas, waste dumping areas, loading-unloading lobbies, concrete placement region= 3-foot candles= 32.292 lux.
According to OSHA guidelines, this lux level is sufficient and mandatory for specifically mentioned applications.
Now that the concept of lux and the overall requirement of lux for your need is discussed, you must consider buying suitable light fixtures. LED fixtures are one type of light source that can provide precise lux levels for different requirements, and also offer several photometric benefits. Along with the lux consideration, it is important that you source lighting solutions from trusted manufacturers like E2 Lighting USA. The company offers several LED fixtures that are manufactured in compliance with OSHA guidelines.