MJBizDaily Buyers Guide Lighting mjbizdaily.com Moles-The measurement of photons emitted by a light source. Narrow-Band Spectrum-LED lights limited to the red and blue spectrums, sometimes referred to as " blurple " lights because of the purple-pink color they emit. Narrow-band spectrum lights are more energyefficient than broad-band spectrum or white lights (see above) and are often used in greenhouse situations where sunlight is also utilized. PAR (Photosynthetically Active Radiation)-The waveband of light from 400 to 700 nanometers driving plant photosynthesis and therefore the wavebands that horticulturalists are interested in measuring. PAR also equals light intensity and the terms are often used interchangeably. Photons-Tiny particles of energy (light) in the PAR range. Photons are converted into useful energy by plants through the photosynthetic process. Different photons have different wavelengths-a blue photon has a short wavelength and a red photon has a longer wavelength. Photons are measured in micromoles. Photoperiodic Lighting-Delivering low-intensity lighting to create long lighting days when actual days are short. PPF (Photosynthetic Photon Flux)-The total amount of PAR light emitted by a fixture each second. The values of PPF vary widely from one fixture to another. Some fixtures emit a tremendous amount of light, so growers need fewer fixtures to obtain their desired light intensity. Others emit very little light and growers thus need more fixtures to meet their desired light intensity. PPFD (Photosynthetic Photon Flux Density)-The PPFD is the light intensity (or photons) delivered to a given surface per second. Light intensity decreases as the distance from the light source and surface increases. PPFD is measured using a quantum sensor and is used to calculate DLI (see above). Quantum Sensor-Also known as a " PAR meter. " Measures the intensity of light, or the numbers of photons emitted by a source of lighting, using micromoles per square meter per second as the unit of measurement. Sole-Source Lighting-Lighting for crops grown entirely indoors with the only light available coming from electric lighting. Supplemental Lighting-Moderate-intensity lighting delivered at night or on cloudy days to supplement a low DLI and increase plant growth and quality. 18 Copyright 2021, MJBizDaily, a division of Anne Holland Ventures Inc. You may NOT copy this report, or make public the data and facts contained herein, in part or in whole. For more copies or editorial permissions, contact CustomerService@MJBizDaily.com or call 720.213.5992 ext. 1.http://www.mjbizdaily.com