Photosynthetic Photon Flux (PPF)

µmol/s

Amount of PAR produced by a light source per second OR the total number of photons per second with wavelengths between 400nm - 700nm.

Photosynthetic Photon Flux Density (PPFD)

µmol/s-m2

Amount of PAR landing on a square meter per second OR density of PPF on a target surface.

Planckian Locus

Planckian Locus is a term often associated with colour of a light-source and how ‘hot’ it looks.

Plant Biologically Active Radiation (PBAR)

According to ASABE*, plant biologically active radiation covers a more substantial range of light (280nm - 800nm) that affects plant biology.

Printed Circuit Board

Insulating board containing conductive tracks for circuit connections.

Radiometry

Radiometry is a set of techniques for measuring electromagnetic radiation, including visible light.

Ray Sets

These are typically used for modelling the performance of optics when combined with any additional optics or reflective surfaces. A ray-set can be generated for any optic and LED combination.

Reflector

Cold Light Reflectors reflect visible light while passing infrared light through the reflector

SMT (Surface-Mount) LED

SMT LEDs are soldered to the surface of the circuit board. The LED die is integrated into the package design.

STEP or STP

This is one type of file format (e.g. 'Part name.STEP') used to save and exchange CAD data.

TIR (Total Internal Reflection) Optic

When light passes from a high refractive-index medium (such as glass) to a low refractive-index medium (such as air) there is a special angle, known as the critical angle, above which light is 100%

TIR Lens

TIR stands for total internal reflection. A TIR lens is a lens that focuses light (or a part of it) via total internal reflection.