Radiation - MMM Tech Support

As the driving force of photosynthesis, light is of critical importance to plants. Plant growth and development is significantly affected by both the amount and type of Radiation. Traditionally, light is thought of as a high-frequency electromagnetic wave. In quantum physics, light is no longer regarded as a classical wave, but as a quantum object. Accordingly, light is composed of individual energy quanta, the photons. Photons are measured in moles (1mol = 60.2 x 1023).

For agricultural and horticultural applications, the intensity radiation is measured in different wavelength ranges:

Pyranometer / Global radiation (wavelength range about 300 to 1100 nanometers), represents the total irradiation from the sun. Measurement of global radiation are used for Et calculation and solar energy utilization. Unit: watts per m².

PAR radiation (wavelength range approx. 380 to 780 nanometers), maps the wavelengths used primarily by plants for photosynthesis (PAR = Photosynthetic Active Radiation). Their measurement complements statements about plant growth conditions. Unit: μmol photons per m².

UV radiation (wavelength range approx. 250 to 400 nanometers). UV radiation triggers stress reactions in humans, animals and plants (e.g. sunburn), measurements are further used to determine the UV filtering capacity of greenhouse shading and heat protection glazing. Unit: μmol photons per m².