What is PAR,PPF,PPFD,YPF&YPFD?
What is PAR,PPF,PPFD,YPF&YPFD?
Photosynthetic Active Radiation (PAR)
The radiation of a specific wavelength range (400-700nm) used by plants for photosynthesis is called photosynthetically active radiation, and there are two labeling units:
One is expressed in photosynthetic irradiance (w/m2), which is mainly used for generalized research on photosynthesis of sunlight.
The second is expressed by the photosynthetic photon flux density PPFD (umol/m2s), which is mainly used for the study of plant photosynthesis by artificial light sources and sunlight.
This method of using the photon flux radiated to the surface of the plant per second to express the radiation ability of the radiation source is called the PPF_PAR method.
PAR accounts for about 50% of the total solar radiation. It should be noted that the unit of photosynthetic irradiance does not reflect the influence of wavelength.
Photosynthetic Photon Flux (Photosynthetic Photon Flux) refers to the number of micromoles of photons radiated by artificial light sources per second in the wavelength range of 400-700nm, in umol/s.
PS: It measures the total amount of light produced by a light source per second. In other words, PPF tells us how much a light source emits per second. Technically speaking, PPF measures "photons synthesized by light emitted by the lighting system every second." This measurement is expressed in terms of "micropores per second." Nevertheless, PPF does not tell us how much of the measured light is on plants or other surfaces.
Photosynthetic Photon Flux Density (Photosynthetic Photon Flux Density) corresponds to PPF is the number of micromoles radiated by the light source per square meter per second, the unit is umol/m2s, which is the concept of density.
PPFD is PPF expressed in one square meter.
PPFD is a physical quantity related to the radiation distance, which is inversely proportional to the square of the radiation distance.
1PPFD means that 1 micromole of photons per second radiates on a surface of 1 square meter.
How big is 1umol/m2s (PPFD)? It means there are 6 photons in 10 square nanometers.
PS: PPFD measures the light reaching plants or algae. Photosynthetic photon flux density or "PPFD" is a measure of the amount of light that actually reaches plants and algae, or a scientist might say: "The number of photosynthetic photons that occur per second on a given surface." PPFD is a " "Point" measures a specific position on the canopy of your plant. It is measured in micro holes per square meter per second. This measurement method is expressed by scientists and optical engineers: mol/m2/s.
The photon flux produced (Yield Photon Flux)
refers to the number of micromoles of photons radiated per second in the wavelength range emitted by the artificial light source, in umol/s. The generally considered wavelength band is 360-760nm, for LED light sources, the wavelength range is set to 380-800nm.
The photon flux density produced (YieldPhotonFluxDensity)
corresponds to YPF is the number of micromoles of radiation per square meter per second, the unit is umol/m2s, which is the concept of density.
YPFD means YPF in the range of one square meter.
YPFD is a physical quantity related to the radiation distance, which is inversely proportional to the square of the radiation distance.
YPFD can more accurately express the light quantity of LED plant light quality.
For the red light blue spectrum, YPF=PPF, other spectrum PPF
The difference between PAR and PPFD, PAR is a physical concept, and the unit of this physical concept of PPFD.
The relationship between PPFD and PPF: PPFD is the basic quantity derived from planting process parameters, and PPF is the main parameter for lamp manufacturing
PS: For the same PPF light source, the relationship between the installation height and PPFD is that the installation height increases, and the PPFD decreases at a rate of 2 power.
Quantitative analysis parameters between different light sources and lamps
For different artificial light sources, the following indicators can be used to compare their spectral parameter performance. These parameters can also be compared with the spectral parameter performance of different manufacturers under the same spectral form of the same light source. Generally, the larger the value, the better. However, the value Large does not mean that the planting efficiency is high, and a professional assessment with professional skills is required.
PPF/w: Indicates the PPF produced per watt of power consumption.
PPFD/w: Represents the PPFD produced per watt of power consumption.
YPF/w: indicates the YPF produced per watt of power consumption.
YPFD/w: Indicates the YPFD produced per watt of power consumption.
The above values are related to the spectral shape (light quality). If these values are divided by the price of the plant light, then the price of the plant light can be compared. The validity of these values requires independent professional analysis by a third party to be reliable.