Photobio Par Light MeterPHOTOBIO PAR LIGHT METER The Phantom PHOTOBIO Advanced PAR Meter is a reliable tool that accurately measures the light emitted by any source used in horticultural settings. By using this device, you can easily monitor the light levels in your grow room and make necessary adjustments to ensure that each plant receives the ideal amount of light. To measure PAR (400 700 nm) within a range of 0 to 3999 mmol m2 s, use the Meter. For optimal photosynthesis,