The research basis of light is spectrum. The application quality of light requires spectral analysis. The spectrum of LED plant lights is particularly important. The manufacturer’s ability to design the spectrum of plant lights determines its market position. The spectrum of LED plant lights needs to be specifically designed according to the planting process. Go for imitation.
The plant factory is a cross-border product. We divide the plant factory technology into planting equipment technology and planting process technology. The plant light spectrum technology is an important connection point between planting equipment and planting process. It needs to be clear that the planting process determines the spectral design. The design and manufacture of the lamp is to ensure that the light quality required by the planting process can achieve the best efficiency. These characteristics of the plant lamp determine the complexity and diversity of the plant spectral design.
I. Non-Visual Applications of Spectrum
Spectral applications are divided into visual applications and non-visual applications. Lighting belongs to visual applications, and plant lighting belongs to non-visual applications. Visual applications and non-visual applications are different in the physical dimension of the spectrum itself. However, many plant lights are still used in lighting Labeling parameters. This parameter labeling that can cause confusion in applications may come from the term “plant lighting.”
The spectrum research of plant photosynthesis is essentially based on the analysis of the optical radiation power or the distribution form and quantity (light quality) of light quantum in the domain of wavelength. This analysis is realized by spectral data and spectrograms.
Planting requires research on the solar spectrum. The solar spectrum tested on the ground belongs to the absorption spectrum. The standard solar spectrum is shown in Figure AM1.5G (G173-03). Due to different geographical locations and seasons, the amount of spectral radiation measured on the ground will be There are differences, but the morphology of the spectrum is the same.
The general theory of photosynthesis in plants is to study the wavelength range of 400nm-700nm. It can be seen from AM1.5G (below) that the wavelength is limited to this range, and the spectral shape is close to rectangular.
In order to provide a reference for the spectral design of artificial light sources, we give AM1.5G maps in the wavelength range of 350-850nm for reference.
Sunlight spectrum has important reference function for plant light spectrum design, but it does not have dependence. Attempting to imitate sunlight spectrum to plant light is a futile and inefficient method.
The ratio of red, green and blue radiation of AM1.5G in the wavelength range of 400-700nm is:
Red light accounts for 32.62%, green light accounts for 35.38%, and blue light accounts for 32.69%.
Analyzing the sunlight of a certain planting area is very important for planting in this area, and it should be actually measured locally with professional instruments so that it can be accurately analyzed. The following figure is the relative spectrum of Nanhai, Foshan in September 2013.
The ratio of red, green, and blue radiation in the 400-700nm wavelength range of this spectrum is:
Red light accounts for 28.7%, green light accounts for 36.58%, and blue light accounts for 35.43%.
It can be seen that the red, green, and blue components in the spectrum are different for different geographical locations, which has a greater impact on the design of sunlight-type and mixed-type plant factories.
Accurate analysis of the local solar spectrum can provide scientific photosynthetic reference for the planting process of solar and hybrid plant factories, and can correctly provide the basis for the selection of supplementary light. For solar plant factories, accurate spectra Analysis is more conducive to the way SPA.
It should be noted that the solar spectrum is different from the spectral analysis dimension of artificial light sources. The solar spectrum is suitable for the radiation dimension description, and the artificial light source is suitable for the optical quantum dimension description. A special article will be introduced in this regard.