Popular science in common lighting terms

1. Light

Light is an electromagnetic wave

Visible light: Part of the radiant energy emitted by a light source, that is, the radiant energy that produces vision. It is often referred to as "visible light".

Wavelength of visible light: from 380nm----780nm

The wavelength of ultraviolet light: from 100nm to 380nm, invisible to the naked eye.

Infrared wavelength: from 780nm-- 1mm, invisible to the naked eye.

2. Color temperature

In terms of absolute temperature K. Is to heat a standard blackbody, when the temperature rises to a certain degree, the color begins to change from red - light red - orange - yellow - white - blue - blue, gradually, using the characteristics of this light color change, the light color of a light source and the light color of the black body at a certain temperature at the same time, we will be the absolute temperature of the blackbody called the relative color temperature of the light source.

3. Color Rendering Index (Ra)

Measure the ability of a light source to produce the true color of an illuminated object

The higher the color rendering index (0-100), the closer the color reproduction is to the natural primary color

4, luminous flux (lumen Lm)

Represents how much light the luminous body emits, lumen is a unit of luminous flux. (The more luminescence, the greater the number of lumens)

5. Light efficiency

The ratio of the luminous flux produced by a light source to the electrical power consumed. Unit: lumen/watt (Lm/W)

6. Average life expectancy

Also known as rated life, it refers to the number of hours when a batch of lights is lit until half of the number is damaged and not lit.

7. Light intensity

Unit of luminous flux in unit solid Angle: cd

8. Illumination

Illuminance is used to describe the degree of illumination on the illuminated surface (working surface), usually expressed in terms of the luminous flux accepted within its unit area, in lux (lx) or lumens per square meter (lm/m2).

9. Brightness

Brightness is used to represent the physical quantity of the luminous (or reflective) strength of the surface of the object, the ratio of the luminous intensity of the luminous surface of the object in the direction of the line of sight and the projected area of the luminous surface perpendicular to the direction, called the surface brightness of the luminous surface, the unit is Candela per square meter (cd/m2).

10. Luminous efficiency

Usually referred to as light efficiency, is to describe the quality of the light source and the economic optical amount, it reflects the light source in the consumption of unit energy at the same time radiation flux, the unit is lumen per watt (lm/w)

11. Beam Angle

Refers to the Angle of light lamp lamp cup Angle. Generally, there are 3 kinds of 10°, 24° and 38°.

12, the appearance of color and illumination

The color rendering index of the light source together with illuminance determines the visual clarity of the environment. There is a balance between illuminance and color rendering index. The results obtained from extensive experiments are: lighting an office with a color rendering index Ra>90, in terms of its appearance satisfaction, than lighting an office with a low color rendering index lamp (Ra<60), the illuminance value is more than 25% higher.

It should be noted that for a good visual appearance, it is not feasible to reduce the indoor illumination to a level that deteriorates the visual function in order to save energy. The light source with the best color rendering index and high luminous efficiency should be used as far as possible to obtain a good visual appearance with the minimum energy cost.

13, the relationship between color temperature and illuminance level

14. Light environment

Light environment is people's psychological feeling of light in a certain visual space.

A good light environment gives people a good visual feeling, which directly affects people's physical and mental health.

When people consider creating a good light environment, they should consider the problem of energy saving. The concept of green lighting is how to reduce the release of mercury, how to save the limited energy that human beings can survive.