The working area is usually made up of the entire workplace/workstation. For example, in an office workplace, the working area is made up of a small surface where paper work is carried out. Work with a monitor and keyboard usually demands a lower illuminance than when paper work is performed.
The illuminance level needs to be adjustable for work with monitors and to help achieve a suitable balance with the surrounding area. Adjust relative to the surrounding areas illuminance.
In an office where paper work is carried out the workspace can be made up of an entire work table. In industry, the size of the working area can be harder to define e.g. workplaces for work involving microelectronics or a production line for assembling cars.
When the exact size of the working area is unknown, it is normally taken as 0.6 m x 0.6 m for an office workplace. In this case the working area is thought to be located directly in front of the person’s normal position and at the front edge of the desk. The variation of the illuminance, i.e. the ratio between the lowest illuminance in relation to the average illuminance on the working area, should be as small as possible and not fall below 0.6.
The tables the latest revision of EN 12464-1 outline the requirements for uniformity separately for each type of work task or activity.
Lighting of the immediate surroundings
The lighting of the immediate surrounding area should relate to the lighting level within the working area and additionally create the conditions for a well-balanced luminance distribution within the normal field of vision. Extensive changes to the lighting level around the working area can cause visual stress and discomfort.
The immediate surrounding area is defined as an area around the working area with a width of at least 0.5 metres. The size of the immediate surroundings should be determined by the planner and may need to be increased to a width greater than 0.5 metres, for specific types of workplaces.
The size of the immediate surroundings can be increased:
- When the size of the working area is small.
- If the illuminance within the working area is high.
- With active work.
The illuminance in the immediate surrounding area can be lower than within the working area, but should not fall below the values stated in the table to the right.
The variation of the illuminance, i.e. the ratio between the lowest illuminance in relation to the average illuminance in the immediate surroundings, should be as small as possible and not fall below 0.4.
1. Working area (laxwa)
– size and position are established by the lightplanner.
2. Immediate surrounding area (loxwo)
– The size to be established by the light planner. (la+2x≥0.5 m)x(Wa+2x≥ 0.5 m).
3.Peripheral surrounding area
– 0.5 metres from the room’s walls.
Lighting of the peripheral surroundings
There are no defined demands on the illuminance within the peripheral surrounding areas in the EN 12464-1, i.e. the area outside of the immediate surrounding area.
This area is defined as the area outside the immediate surrounding areas, to a distance of 0.5 metres from the room’s walls, or to a band around the immediate surroundings with a width of at least 3 m. The illuminance within the peripheral surroundings must be at least a third of the illuminance in the immediate surroundings.
The illuminance variation, i.e. the difference between the lowest illuminance and the average (mean) illuminance of the peripheral surroundings, should be as small as possible. Uniformity, i.e. the ratio between Emin / Eave must not be less than 0.1.
If, for example, demands on the illuminance within the working area are 500 lx on the workplace and and 300 lx for the immediate surroundings, then the illuminance of the peripheral surroundings must not be less than 100 lx.
The minimum illuminance shall be calculated within a zone outside the immediate surroundings to 0.5 m from the walls of the room, or to a band around the immediate surroundings with a width of at least 3 m.
The lighting around the working area should contribute towards good visual adaptation, as recommended in the luminance distribution and luminance limitations section of the report.
As a rule, in work areas with bright walls, the relation between the illuminance within the working area and the average illuminance on the room´s walls should not exceed 3:1.
the working area
Illuminance within the
Illuminance within the peripheral
surroundings in relation to the
|≤ 50||Eworking area||1/3|
|Uniformity within the working area depending on the visual task and activity. Uniformity in the immediate surroundings: min/avg at least 0.4. Uniformity in the peripheral surroundings: min/avg at least 0.1.|