There are a variety of tools available for measuring PPFD, including quantum meters, light meters, and smartphone apps. Quantum meters are specialized devices designed specifically for measuring PPFD and are typically more accurate and reliable than other types of PPFD measurement tools. Light meters are more general-purpose devices that can measure a wide range of light intensities and wavelengths, but may not be as accurate as quantum meters for measuring PPFD. Smartphone apps are a convenient and low-cost option, but may not be as accurate as dedicated measurement tools.