The same as traditional light source, Led tube light sources' as with traditional light sources, LED tube light source of optical measurement units are unified. To our readers to understand and easy to use, following a brief introduction to the knowledge:
First, the luminous flux
Led tube light flux is emitted per unit time in the amount of light that radiated power can be felt by the human eye that part of radiation energy. It is a band per unit time is equal to the radiation energy and the band see the rate as the product of the relative. Since the human eye relative to different wavelengths of light as see different rates, so the radiation power of different wavelengths of light are equal, not equal luminous flux. Symbol flux Φ, unit lumen (Lm).
According to spectral radiant flux Φ (λ), so you can come flux formula:
Φ = Km ??Φ (λ) gV (λ) dλ
In the formula, V (λ) - depending on the relative spectral light efficiency; Km-radiation spectrum of light as the maximum performance, the unit is Lm / W. Measured in 1977 by the International Committee to determine Km values 683Lm / W (λm = 555nm).
Second, the light intensity
Led tube light intensity is defined as per unit area per unit time by the light energy, energy and frequency proportional to their strength and (or points) can also be understood as the light source in a given direction is the luminous intensity I The light source in the solid angle element in the direction of the flux dΦ transmission divided by the solid angle element dΩ of Commerce
Unit of luminous intensity is the candela (cd), 1cd = 1Lm/1sr. The light intensity in all directions of space is the sum of flux.
Third: and brightness
Our LED tube in the test chip evaluation of LED tube light brightness and radiation safety in the process, the general imaging, can be used for testing the chip micro-imaging measurements. Brightness is the light source at the surface brightness of a particular L, is the surface element dS in a given direction divided by the luminous intensity on the panel perpendicular to the surface of the projection given area of business
Brightness of the unit is the candela per square meter (cd/m2). When light and measuring the direction perpendicular to the surface, then cosθ = 1.
Fourth, light
Led tube light intensity is the extent of the object is illuminated by the luminous flux per unit area expressed accepted. Light intensity and light source, the illuminated surface and the light in the space of position, size and the light source and light intensity is proportional to the angle of incidence, and with the light source to the illuminated surface is inversely proportional to the square of the distance. Illumination point on the surface E is the incident contains the points in the flux dΦ panel divided by the area dS of the operators panel.
In units of lux (LX), 1LX = 1Lm/m2.
