LUMEN ,Spectrum& PAR METERS

Lumens measure the intensity of light to the human eye, but not necessarily the spectrum of the light. Photosynthetically Active Radiation (PAR) meters measure light intensity within the spectrum that plants use most to photosynthesize (excluding UV light) from 400 to 700 nanometers, which covers both the blue and red spectra of light. Use these meters to measure how well your lights are covering your grow footprint and adjust your light setup accordingly.