With the development of urbanization in China, greenhouse vegetables have been planted in many places. The first requirement for greenhouse vegetables is the light condition, which directly affects the development, quality and yield of vegetables. If the light is insufficient, it will affect the photosynthesis of the crop and the transpiration will be reduced, which will affect the normal growth of the vegetables, so we need to improve the light in the greenhouse through some methods.
In addition to objective factors in greenhouse vegetables, the light transmittance of greenhouse films is also very important for greenhouse vegetables. Therefore, for new greenhouse film, we generally use a window tint detector to measure whether the light transmittance value is acceptable. Let's take a look at some of the methods that can improve the light of greenhouse films.
Keep the plants tall and orderly. Reduce the occlusion as much as possible. Regardless of what vegetables are planted, try to keep the same size.
If there is water droplets or dust on the top of the greenhouse, it will cause a decrease in the transmittance of about 30%. When the new greenhouse film is just bought, the transmittance value is measured with a window tint detector. After two days, ten days and half a month, the light transmittance reduction rates were 14%, 25% and 28% in turn. Therefore, it is necessary to wash and clean the greenhouse film frequently to increase its light transmittance.
When choosing greenhouse film, it is best to choose a non-dropping film, because the active agent added to the non-dropping film can weaken the affinity of water molecules and the film. Water droplets will flow along the edge of the film to the ground, Increasing the light intensity can also increase the overall temperature of the greenhouse. At the same time, when selecting a greenhouse film, use a window tint detector to measure the light transmittance of the film and try to choose a greenhouse film with high light transmittance.
Under the premise of ensuring the temperature, we can also open the straw curtain or cover the straw curtain in advance, so that we can extend the time of sunlight and increase the light transmission in the shed.
If you only need to measure the light transmittance of transparent greenhouse film, it is recommended to use Linshang LS116 window tint detector. The light source of this window tint detector is the full wavelength of 380nm-760nm, which meets the CIE photopic luminosity function. The instrument which adopt the parallel light path design can also measure large thickness tested material. The measurement accuracy can reach within ± 1%, which ensures that it can pass the test of the Chinese Metrology Institute.
For testing of visible light transmittance, ultraviolet, infrared transmittance or rejection rate of greenhouse films, it is recommended to use Linshang LS163 transmission meter. This instrument can measure visible light from 380nm-760nm, ultraviolet light with a peak wavelength of 365nm and infrared light with a peak wavelength of 940nm. The instrument can set the transmittance or IR and UV rejection rate.