LED strip_LED strip light_LED strip lighting

The LED Devices Photometric Parameters Were Measured

By: DeRun   Views:6605   Date: 05/19-2013

Photometric and radiometric parameters:
1.Flux ? v (Luminous Flux): Forward current through the light emitting diode when a predetermined value, the luminous flux emitted optical window of the device.
2.luminous intensity Iv (Luminous Intensity): flux emitted by the light source unit solid angle, can be expressed as IV = d? / d?.
3.relative spectral energy (power) distribution P () (Relative Spectral distributions): distribution of the radiant energy of the respective wavelengths in the wavelength range of optical radiation.
4.Peak Emission Wavelength p (Peak Emission Wavelength): a wavelength corresponding to the maximum value of the spectral radiant power.
5.half-wave spectral width delta (Full Width Half Maximum, FWHM): The peak emission wavelength of the radiation power of 1/2 corresponding to the two-wavelength interval.

LED luminous flux:

Radiometric, LED radiant flux E used to measure the total electromagnetic power emitted by the light emitting diodes in the unit of time, the unit is W (watt). It is usually expressed in the space within the range of 4? degrees, LED power emitted per second. LED light source, the radiation emitted flux can cause that part of the human visual called luminous flux V, unit is the lumen (lm), similar to the concept of radiant flux, which is emitted in unit time by the LED light source to the entire space can cause the human visual radiation flux.

But to consider the human eye is different for different wavelengths of visible light feeling, the International Commission on Illumination (CIE) in the human eye sensitivity to a different wavelength monochromatic been summarized under photopic conditions (brightness above 3cd/m2), boils down to a standard photometric observer of the human eye spectral the optical efficiency function V () at 555nm maximum 1W radiation flux 683lm.
The measurement usually to photopic conditions as the measurement conditions, and in measurement, the LED in order to obtain accurate measurement results must power the optical radiation emitted by the LED is collected, and with a suitable detector (spectrum having a CIE standard photometric observer spectral response function of the optical efficiency) which is linearly converted into a photocurrent, and then determined through calibration and measured size.

 Leave A Message :
Do Not Know, Another Picture.
ce rohs ul cul certification