Thanks, @Icemud . Even "back in the day" when HID lighting was pretty much it, we learned that lux/lumen was really only useful when used to compare two different (power) products from the same manufacturer, and sometimes not even then. Such things were wholly intended to be used for things such as illuminating human-occupied spaces, AFAIK. Living rooms, theaters, etc.
LED grow light manufacturer produces a light. The next year, *everything else* is the same, except that the manufacturer adds a few percent more red-spectrum diodes, remove an equal number of some other type in order to make room from them - and, even if the developer of a "PAR" phone app had specifically entered the characteristics of the specific product into a database (along with several hundred other products, which is probably not how they do these things), and the user has to select the light's brand/model from a big list... that data will now be wrong and, therefore, any "data conversion" that the app does in order to use the phone's sensor to... estimate the PAR output of that light will be incorrect.
That's why I don't bother. They can tell a person that turning the dinner knob counterclockwise will decrease the light's output, lol - but so can common sense and a basic electricity measuring device (e.g. Kill A Watt).
LED grow light manufacturer produces a light. The next year, *everything else* is the same, except that the manufacturer adds a few percent more red-spectrum diodes, remove an equal number of some other type in order to make room from them - and, even if the developer of a "PAR" phone app had specifically entered the characteristics of the specific product into a database (along with several hundred other products, which is probably not how they do these things), and the user has to select the light's brand/model from a big list... that data will now be wrong and, therefore, any "data conversion" that the app does in order to use the phone's sensor to... estimate the PAR output of that light will be incorrect.
That's why I don't bother. They can tell a person that turning the dinner knob counterclockwise will decrease the light's output, lol - but so can common sense and a basic electricity measuring device (e.g. Kill A Watt).