Spectrometer and Quantum Sensor can cost hundreds to thousands of dollars and not every grower can afford them. A simple Lux meter or Lux meter app on phone can be used to ensure even light spread across canopy.
This guide gives an estimate for converting Lux to PPFD. Data used in this calculation is form HLG 550 lab reports. The converted PPFD data will be accurate if the entered Lux data is accurate.
QB 288 3000K
|QB 288 V2||80833.17||1178.05||68.61607742|
|QB 288 V1||77963.72||1159.35||67.2477854|
Just divide the Lux value you are getting with the Lumens/PPF to get the PPFD value.