# Illumination and brightness calculation (Graphic)

The illumination is used to represent the strength of the illuminated surface is on, in terms of the illuminated surface flux density places, units for Lux (LX). LLX is said to be evenly distributed in 1, nZ, the luminous intensity of 1 LM flux. Use E to express.

The light environment should make it easy for people to identify the details of the work he does, and to eliminate or properly control the factors that cause visual discomfort. For a variety of buildings and places of illumination value, see Chapter 1 introduction. The values given are the average illumination value and the illumination range by three successive illumination level (e.g. 50 75 100), intermediate values represent the recommended value, taking into account the work itself, reflectance contrast, work and the importance of factory staff factors such as age, can be used high value or low value in the design in addition to meet the illumination requirements, but also should satisfy the requirements of illumination uniformity. The relationship between the minimum illumination Emin and the average illuminance Eep should be: Emin>Eep>/0.7.

1 direct light illumination calculation when the source and target plane distance is greater than 5 times the size of light source, the light source can be regarded as a point light source, point source in the horizontal plane illuminance obey the inverse square law and the law of cosines, see Fig.

Type Eh - horizontal illuminance (LX)

The light intensity I lamp irradiation direction (CD)

L light source (lamp) and calculated the distance (m)

H light source from the working face height (m).

When a plurality of light sources are irradiated at a point on a plane at the same time, the synthetic illuminance of the point is equal to the arithmetic and the illumination of the illumination of each light source.

Considering the luminous flux output to the lamp in the process of using light bulb lamps because of attenuation, dust and pollution caused by the reduced room surface, so that the illumination of the illuminated surface is reduced, the molecular formula in the illumination to lead people to maintain the coefficients K, K value table

Environment classification

Maintenance coefficient K

Lamps (times of scrubbing times per year)

Since the incandescent lamp fluorescent lamp and high pressure gas discharge lamp

Tungsten halogen lamp

I have the smallest dust (clean)

0.75

0.80

2

A small amount of dust (general)

0.70

0.75

2

More dust (serious pollution)

0.65

0.70

3

Outdoor IV

0.70

0.75

2

2 line direct light illuminance calculation of line source refers to the width of B and length of L luminous body is much smaller, usually a continuous column lamp (or tube) belongs to this kind of practical application, all kinds of line source, the longitudinal plane intensity distribution curve, and use the following five kinds of theories of light intensity distribution curve to represent

A point normal illuminance (illumination generated in the plane perpendicular to the direction of illumination) can be calculated by pressing:

The horizontal surface of the A point can be calculated by pressing: