Illumination of workplaces EN 12464
EN 12464 was developed in extensive discussion as a European standard and is valid throughout Europe and in a similar form as ISO 8995 standard also worldwide.
EN 12464-1:2011 Light and lighting - Lighting of work places - Part 1: Indoor work places, lists the lighting criteria that continue to be a prerequisite for lighting quality:
- Pleasant lighting climate
- Harmonious luminance distribution
- Sufficient illuminance according to the in the tables 'List of lighting systems requirements'.
- Good uniformity
- Limiting direct and reflected glare as well as of veil reflections
- Correct direction of light and pleasant modelling
- Suitable light colour and colour rendering
- Avoid flickering and stroboscopic s effects
- Taking daylight into account
In addition to the content of EN 12464, the requirements for the calculation grid from EN 12193 "Sports facility lighting" are also adopted and recommended.
Service value of the illuminance
The illuminance values specified in the standard for the visual task area and the immediate surrounding area are service values, i.e. values below which the mean illuminance on an assessment surface must not fall.
Maintenance of the lighting system
To ensure that the desired lighting level, expressed in terms of maintained illuminance, can be maintained for an appropriate period of time, this reduction in luminous flux must be taken into account in the design of a lighting system by setting an appropriate service factor.
Area of the visual task and immediate surrounding area
The visual task area is defined as the part of the workstation where the visual task is performed. The visual performance required for the visual task is determined by the relevant elements of the task to be performed. The immediate surrounding area is defined as the area within the field of view that directly surrounds the visual task area. According to EN 12464, this surrounding area must have a width of at least 0.5 m and can therefore be regarded as a strip surrounding the visual task area. If the size and/or location of the visual task area is not known, the area must be assumed to be the visual task area in which the visual task can occur.
It is recommended to combine several areas of the visual task according to EN 12464 into one larger working area. If the location of the workplaces is not known, this working area can also be the entire room. If illuminance is distributed over these larger areas with a uniformity of g ≥ 0.6, it can be assumed that the requirement g ≥ 0.7 is always met in the individual areas of the visual task.
Glare is caused by areas of too high luminance or by too great differences in luminance in the field of view of an observer. Glare that leads to an immediate reduction in vision is called physiological glare. Glare that leads to a reduction in well-being and is assessed from the point of view of sensation of disturbance is psychological glare.
Several different visual tasks often occur at workplaces in industry. Their position and size must be determined in detail. If the individual visual tasks are comparable, a working area can be defined in which the visual tasks can occur. The immediate surroundings to be considered are in a strip 0.5 m wide around the working area. However, it is advisable to install general lighting for the entire area to provide sufficient light for all workplaces.
Shop floor with zones for different activities
In an factory building, several visual task areas with different illuminance requirements must be expected. In this case, it is recommended that the entire hall, less a 0.5 m wide edge strip on the wall, be considered the visual task area with the lowest requirements. In this case, the immediate surrounding area does not have to be assessed separately either. as, as a rule, the requirements for the surrounding area are automatically fulfilled.