:format(jpeg) "LUX simply explained")
LUX
simply explainedLux, the unit of measurement for illuminance, is rarely used in private households due to the complex calculation involved and is not required for optimum living and working light. In a commercial context, on the other hand, the calculation of lux is important to fulfil legal standards.
What is Lux?
The unit of measurement lux (lx) indicates the illuminance: 1 lux means that an area of 1 m² is uniformly illuminated with 1 lumen.
So while the brightness of a light source is given in lumens, lux refers to the light that reaches a surface - e.g. a table.
As the luminous intensity (candela) of the light source, the distance to the surface and spatial conditions affect the value in addition to the lumen, the lux value is not given in the product details.
)
)
How do you calculate lux?
A luxmeter is required for an exact calculation of the illuminance, as light reflections from walls and ceilings, for example, also have an influence on the value. You can roughly calculate the lux value with :
- Candela value of a light source
- Distance of the light source to the illuminated surface
The formula for calculating the lux is
Lux = Candela / distance² (in metres)
An example: A light source with a beam angle of 90° and a luminous flux of 320 lumens has approx. 170 candela. It hangs in a pendant light 80 cm above the dining table top. This results in an illuminance of around 270 lux.
:format(jpeg) "Calculation LUX")
1. Distance (r)
2. Candela (cl)
3. Lux (lx)
Illuminance levels of artificial and natural light - an overview
For workplaces, the calculation of illuminance based on the guideline values of the European standard DIN EN 12464-1 "Lighting of workplaces - Indoor workplaces" is mandatory. ASR A3.4 "Lighting" and other special regulations, e.g. for street lighting, may also apply. There are no regulations for private households.
)
Cosy ambient lighting in the living room, bedroom or dining room measures around 300 lux. This is often achieved by ceiling or pendant lighting.
)
For highly light-dependent activities such as sewing or reading, around 500 lux is ideal. Additional light sources such as floor and table lamps are used for this purpose.
)
If you want it to be particularly cosy, the light in the living room is often dimmed down, for example to around 50 lux.
)
Around 500 - 1,000 lux are required on the desk. Ceiling washlights with a direct light component or desk lamps are good options.
)
10 to 50 lux as an orientation light is enough to avoid bumping into the edge of the bed at night, for example, without disturbing your sleep. LED strips are a good solution that is also particularly visually interesting.
)
Natural daylight reaches up to 100,000 lux on cloudless summer days, a cloudy sky 20,000 lux. In winter, an overcast sky reaches around 3,500 lux. At dusk there are approx. 750 lux. On a full moon night it is 0.25 lux.
How many lux are the twilight sensor and motion detector set to?
Many sensors, e.g. on outdoor wall lights, can be set to a lux value above which they switch on. This is usually set to 10 lux. However, the correct switching on of the light should be checked. The sensitivity can be adjusted from a few lux up to 1,000 lux or 2,000 lux, depending on personal preference and structural conditions. The adjustment is often made with a spanner on an adjusting screw - subsequent adjustment is therefore uncomplicated. The instructions provide precise information on the correct setting.
)
:format(jpeg) "Twilight sensor and motion detector")