Paper
1. Illuminuation
Factors that affect the workers’ visual performance are visual angle, contrast, illuminance, glare and color. One way to improve the worker’s visibility is to improve direct lighting. Direct lighting however, deemphasizes the ceiling surface and places more of the light on the work surfaces and the floor. Direct-indirect lighting is a combination of both and is recommended in all work areas. Too much glare, or excessive brightness might also affect the worker’s vision. A table below shows the recommended illumination levels for different types of activities. Lastly, color has psychological effects on people. Proper designation of color will provide more visual comfort for the workers.
Calculations:
Visual angle (arc min) = 3,438 x h/d
Where h = height of the target, and d is the distance from the target to the eye
Contrast = (Lmax – Lmin)/Lmax
Reflectance = 0.9 x Ltarget/Lstandard Where L is luminance and is measured with a photometer
Standards or Recommended Illumination Levels
Category
Range of Illuminance
Type of Activity
Reference Area
A
2-3-5
Public areas with dark surroundings.
General lighting throughout room or area.
B
5-7.5-10
Simple orientation for short temporary visits.
C
10-15-20
Working spaces where visual tasks are performed only occasionally.
D
20-30-50
Performance of visual tasks of high contrast or large size (ex: reading printed material).
Illuminance on task.
E
50-75-100
Performance of visual tasks of medium contrast or small size (ex: reading medium-pencil handwriting).
F
100-150-200
Performance of visual tasks of low contrast or very small size (ex: reading handwriting on poor-quality paper).
G
200-300-500
Performance of visual tasks of low contrast and very small size over a prolonged period (ex: fine assembly).
Illuminance on task via a combination of general and supplementary local lighting.
H
500-750-1000
Performance of very prolonged and exacting
Factors that affect the workers’ visual performance are visual angle, contrast, illuminance, glare and color. One way to improve the worker’s visibility is to improve direct lighting. Direct lighting however, deemphasizes the ceiling surface and places more of the light on the work surfaces and the floor. Direct-indirect lighting is a combination of both and is recommended in all work areas. Too much glare, or excessive brightness might also affect the worker’s vision. A table below shows the recommended illumination levels for different types of activities. Lastly, color has psychological effects on people. Proper designation of color will provide more visual comfort for the workers.
Calculations:
Visual angle (arc min) = 3,438 x h/d
Where h = height of the target, and d is the distance from the target to the eye
Contrast = (Lmax – Lmin)/Lmax
Reflectance = 0.9 x Ltarget/Lstandard Where L is luminance and is measured with a photometer
Standards or Recommended Illumination Levels
Category
Range of Illuminance
Type of Activity
Reference Area
A
2-3-5
Public areas with dark surroundings.
General lighting throughout room or area.
B
5-7.5-10
Simple orientation for short temporary visits.
C
10-15-20
Working spaces where visual tasks are performed only occasionally.
D
20-30-50
Performance of visual tasks of high contrast or large size (ex: reading printed material).
Illuminance on task.
E
50-75-100
Performance of visual tasks of medium contrast or small size (ex: reading medium-pencil handwriting).
F
100-150-200
Performance of visual tasks of low contrast or very small size (ex: reading handwriting on poor-quality paper).
G
200-300-500
Performance of visual tasks of low contrast and very small size over a prolonged period (ex: fine assembly).
Illuminance on task via a combination of general and supplementary local lighting.
H
500-750-1000
Performance of very prolonged and exacting