PBFD

Seen it on a few light sights, "PBFD is a total count of light energy (in photons) from 350nm to 800nm (or the PBAR range used)"

Of relevance or not?

...maybe this help you a bit...

https://eyehortilux.com/grow-lighting-guide/measuring-light-for-plant-growth/ppfd-pbfd/

Photosynthetic Photon Flux Density (PPFD) is the metric used to measure PAR over a square meter.
It is a total count of light energy (in photons) from 400 nm to 700 nm that reaches a particular point on a plane.

PhotoBiological Photon Flux Density (PBFD) is the metric used to measure PBAR over a square meter.
It is a total count of light energy (in photons) from 350 nm to 800 nm (or the PBAR range used) that reaches a particular point on a plane.

PD...por los Likes...os pongo my POV..

my POV....i prefer the IES.org opinion ...
...280 nm to 800 nm (often referred to as “PhotoBiologically Active Radiation,” or PBAR).....

PPFD and PBFD are both expressed as μmol/m2-sec.

See how PPFD and PBFD are measured below.



Measuring PPFD and PBFD
PPFD and PBFD are measured using a light meter.
A light fixture will be placed a distance above a plane and measurements will be taken at points within a specified coverage area.
The output of light from a fixture will vary based on the position of the light meter.
For example, a light meter placed directly underneath the center of a fixture may reveal a higher PPFD/PBFD number than when placed in the corner of a 4 ft x 4 ft square.
This is due to the reflector and the properties of its design.

......

Specifying LED Colors for Horticultural Lighting

Plants have a wide range of Photopigments that respond to
...Optical Radiation from 280 nm to 800 nm (often referred to as “PhotoBiologically Active Radiation,” or (PBAR).

These responses include:

• PhotoMorphogenesis – any change in the Morphology (i.e., shape) or Composition of a Plant or its components that is induced by optical-radiation exposure
• PhotoPeriodism – response of a Plant to Daily (Circadian) or Seasonal (Circannual) changes in Optical-Radiation exposure
• PhotoSynthesis – conversion of “Photosynthetically Active Radiation” (PAR) into Chemical Energy stored as Carbohydrates to fuel plant activities
• PhotoTropism – any self-actuated change in the Orientation of a Plant or its components toward or away from Optical Radiation
• Secondary Metabolite Production – Organic Compounds not directly involved in Plant Growth, Development, or Reproduction, including Compounds used as Medicines, Flavorings, Pigments, and Drugs
• Shade Avoidance – a set of responses to being Shaded by other Plants, including changes in Morphology, Flowering Times, and Allocation of Resources

Saludos desde Tenerife

I know what it is just seeing companies start to use it made me wonder just how relevant it is. One company had 17% of its watt developing PBFD spectrum. It lowered the ppfd but the added it together. Some lights would look better if you added the PBFD and LEDs are using PBFD frequency.

Some lights would look better if you added the PBFD and LEDs are using PBFD frequency.?????

....you added the PBFD...??????

...using PBFD frequency.... ??????

LOL....OMG...

Wilson necesito otra cuarta de vino...JEJEJEJE

SALudos

BBQtoast said:

I know what it is just seeing companies start to use it made me wonder just how relevant it is. One company had 17% of its watt developing PBFD spectrum. It lowered the ppfd but the added it together. Some lights would look better if you added the PBFD and LEDs are using PBFD frequency.

Click to expand...

yeah, so the whole radiant flux should be stated, not just PAR.

Kassiopeija said:

yeah, so the whole radiant flux should be stated, not just PAR.

Click to expand...

Never done that before with lights.