Task lighting of the room and the jobs can be solved by the device or General lighting or combined lighting i.e. all General and local lighting.
Is called General lighting fixtures which illuminate the entire area of the premises occupied by the equipment and jobs and support the local illumination is only for a job and not creating the necessary light even in the surrounding areas.
The device alone local lighting is prohibited by the regulations not to mention the fact that you will almost always want to illuminate not only the area of immediate work and adjoining area at a local lighting hampered the work of the eye in a field of view which are significant contrasts. Studies have shown that at a constant total illumination of the working meta the increase in the known extent of the light created the General lighting leads to higher productivity and reduced fatigue.
Rules impose the following requirements for General illumination lighting generated in the system of the combined illumination.
In rooms with natural light General lighting in the combined system must be created on the working surfaces 10% of light established standards for combined lighting and in addition to this, the illumination shall be not less than 50 Lux for the incandescent lamps. Do not need to create a total coverage of more 500лк with gas-discharge lamps or 100 Lux for the incandescent lamps. In industrial premises with constant stay working in the absence of their natural light the percentage of the total illumination in the combined system are given in the table.
Rules of otusenogto
The category of visual work
Illuminance LX of the lamps is General lighting in the system combined
When high pressure discharge lamps
With incandescent lamps
I b IIa
I to IIB
G G IIIB IIIB IV V a V b
Given values are calculated from the normalized light for those light sources which are used for local lighting.
Let for example the room with natural light, the works of category II and local lighting is done by incandescent lamps. The norm of the combined illumination is 2000 Lux where 10 % will be 200лк. If the General lighting is done with gas discharge lamps that takes this value if the lighting is done by incandescent lamps is taken into account that the illumination may not exceed 100лк.
The choice between a device of one common or combination lighting is a rather complicated task whose solution is not always obvious and should