Light Quality and Measurements Flashcards
What is the electromagnetic spectrum and what does it measure?
Streams of photons traveling in a wave-like pattern
Measures electromagnetic radiation
How are visible light and photosynthetically active radiation (PAR) related?
PAR is a subset of visible light
What are the differences between light quality, intensity, and distribution/quantity?
Quality: measure of usable light that is available for plant use
Intensity: brightness of light
Duration: how long the light is available
What are the units of measurement for each ways of approaching light?
Lumens (brightness to human eye)
Lux (brightness in an area)
Watts (energy required to produce light)
PPF (measure of plant usable light per second)
PPFD (PPF measurement as it hits a surface)
What types of light are best for horticultural production?
LED (most efficient, degrade over time)
Sodium (last a long time, produce heat)