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LED Light Lux Levels and Light Measurement and Brightness

The term Lux (lx) is the typical measurement used in various Australian Standards and Building Codes to determine the minimum light levels for various areas so is probably the most familiar and most useful measurement to consider when purchasing a LED light bulb.

Lux is the SI unit of luminance or illumination of a one metre square area, which is equal to one lumen per square meter. Some examples of typical light (lux) levels are given below:

 

Environment

Light Level

 

Average Day

32,000 to 100,000 Lux

 

Overcast Summer Day

30,000 to 40,000 Lux

 

Floodlit Football Match

700 to 16,000 Lux

 

TV studio

1000 Lux

 

Shady Room in Daylight

250 to 300 Lux

 

Night Light on a Building

60 Lux

 

Night-Time Urban Street 

10 Lux

 

Night-Time Car Park

1 Lux

Rather than measuring the total quantity of light produced by the light source, a lux meter will measure the quantity of light distributed over or at a particular area at a specified distance from the light source. For example, if one is attempting to obtain a suitable light level for an office then the ideal position is to measure the light at the height of the work plane or office desk. In contrast, if one is attempting to obtain a suitable light level for an internal corridor then the light would be measured at the level of the floor. If there is no specified plane then the measurement is typically taken at a horizontal plane at 0.75 to 0.8m above the floor.

Many LED bulb manufacturers will provide Lux distribution diagrams which provide a measurement of Lux level at various distances and diameters from the light source. This information can be useful for determining what beam angle you require for your LED light globe such that narrower angles will have a smaller lux/light distribution but higher centre beam lux level at various distances. The converse can be said for LED light globes with wider angles. 60 to 72 degree beam angles are most common in Australia. Narrower beam angles are usually considered for spot lighting in art or retail applications.

Below is a list of typical Lux levels required for different environments.

Building Type

Space Type

Maintained Average Illuminance at working level (lux)

Measurement (working) Height (1 meter = 3.3 feet)

 

Residential

Bedrooms

300

at 0 m

 

 

 

 

Educational Buildings

Play room, nursery, classroom

400

at 0 m

 

Lecture hall

400

at 0.75 m

 

Computer practice rooms (menu driven)

400

at 0.75 m

 

General Use Classrooms

240

at 0.75 m

 

Classrooms for adult education

400

at 0.75 m

 

Lecture hall, Auditorium, Church

240

at 0.75 m

 

Meeting areas

320

 

 

 

 

 

Office buildings

Offices

320

at 0.75 m

 

Board Room

240

at 0.75 m

 

Conference rooms

300

at 0.75 m

 

 

 

 

Commercial

Restaurant or dining room

160

at 0.75 m

 

Kitchen and Food Prep

240

at 0.75 m

 

Retail Space

400

at 0.75 m

 

 

 

 

Sport facilities

halls

300

at 0 m

 

 

 

 

Wholesale and retail sales

Sales and Till areas

500

 

 

 

 

 

Common areas

Circulation Space and Corridors

40-80

at 0 m

 

Stairs

40

at 0 m

 

Public Toilet

80

at 0 m

 

Car Park

40

at 0 m

 

Car Park – Entry Zone

800

at 0 m

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