My bad, i forgot to mention i am talking about Triphosphor FL's and LEDs only, not Halophosphors

And what do you think of the UV emitting lighting? I'm talking about the lamps used in tanning, reptiles, etc.

Quote from: Ash on July 07, 2016, 06:14:23 PM

All /D /CW /WW /"Incandescent equivalent" put out about the same bands in the spectrum, its just the quantities in the mix that are varied. So the light adds the cool or warm tint respectivaly but rendering of colors is still comparable forthe same light technology

So why does WW have 52 CRI while D has 75?

Even with halophosphates there are two components (one peaking around yellow-orange, second in green-blue; but both are rather wide spectrum) the color temperature is varied by the ratio these two major components mix together. Because the halophosphates are not able to generate  that much or red, the colors requiring high red content become of lower CRI, as the color is made mainly by the orange-yellow component.
With the higher CCT "blackbody" the relative red content becomes lower (because of the higher content of the bluish parts), what means even when the halophosphates do not generate the red that much, it is not that much missing, hence the higher CRI of the colder CCT halophosphates compare to their lower CCT counterparts.

High CRI lighting:
For the 95+ you do not suffice just with the narrow peaks of the "tri-phosphors", filling the gaps become important as well. So many designs use the wide band halophosphate-like spectrum as the base and then supplement the sides (deep red,...) parts with the narrow band rare-earth phosphors to correct the defficiencies there.

And regarding the UV beads or so:
There the UV is supposed to do affect the body, so the effect is supposed to be under control (therefore the tight specifications on the spectrum variations and the seemingly short rated life and the penalties the saloons are getting from public health care agencies when not replacing the tubes within that limit). The normal lighting is supposed to serve long time, without such care, therefore it should not affect anby part of the body at all, so the UV limits for it are so strict. This is the main difference.
Now there is debate about the "full spectrum" lighting:
The proponents argue, with the common artificial light the UV exposure may become way too low, mainly w limited outdoor activities. So they want the UV limits to allow some radiation there.
The opponents argue, because it is artificial lighting, the exposure may easily become excessive, just because when it is installed as a lighting, the re is not much exposure control.
The authorities are more on the conservative side - once it physically affect the body, it must be kept under control as a health treatment equipment, requiring the equipment certification, enforcing the proper relamping at the rated EOL, regular inspections,... (there belong e.g. the tanning beads).
If the exposure is not controlled (you do not want to bother the operators with all the testing and inspections), there should be no physical effect at all, so the tight UV limits are in place.

So strictly speaking any offer of a "wide spectrum light with UV content" is in fact illegal: Either there is no UV content (so false advertisemsnt), or the UV exposure is above the limit (then it is not allowed to be offered for lighting fixtures).
And the legal problems with that is the main reason, why major makers do not offer such products at all.
And try to trust some obscure companies with your health...

Why the lamps that combines the halophosphors and the triphosphors to make >90 CRI, have lower efficiency, than the ones with triphosphors only?

Why the lamps that combines the halophosphors and the triphosphors to make >90 CRI, have lower efficiency, than the ones with triphosphors only?

The halophosphates are just less efficient, so they consume more of the primary UV power, while give off less radiated power.

But wasn't the question rather about an EFFICACY (and not efficiency)?
Because there the answer already was: High CRI needs to spent power in wavelengths, that do not generate that much lumens, because the eye is not as sensitive to these. If you suffice with CRI80, you just use that power for wavelengths yielding more lumen output, so you get more lumens for the same radiated power. The difference between CRI80 vs CRI95+ is about 20% in lumens with exactly the same radiated power.
Plus longer wavelengths mean lower energies in those photons, so for the same radiated power you need more of them. And when the best phosphor gives off one deep red photon for a single UV one, it means you need higher UV power for that.

All that together mean the CRI95+ use to have about 30% lower efficacy than an otherwise equivalent CRI80 lamp. With LED's the difference is a bit lower, there is some prospect to lower it even further by the development of the deep red chips (today these offer way lower efficiency than their blue counterparts, but because there are no need for any color conversion, so no photon energy losses in order to get the red part, today the efficiency of the red generated by a blue+phosphor is about the same as with those new red chips, but the reds were lacking the development effort spent on the blue, so it will likely improve faster than the blue ones; plus still the question is the temperature stability of the red chips - they are way more temperature dependent than the blue ones).
But still the efficacy difference will never be smaller than the that 20..25% needed for the spectrum end radiation

"Efficiency" and "Efficacy" are synonyms, so it doesn't matter which word to use.

Quote from: wattMaster on July 07, 2016, 08:27:36 PM

Quote from: Ash on July 07, 2016, 06:14:23 PM

All /D /CW /WW /"Incandescent equivalent" put out about the same bands in the spectrum, its just the quantities in the mix that are varied. So the light adds the cool or warm tint respectivaly but rendering of colors is still comparable forthe same light technology

So why does WW have 52 CRI while D has 75?

Even with halophosphates there are two components (one peaking around yellow-orange, second in green-blue; but both are rather wide spectrum) the color temperature is varied by the ratio these two major components mix together. Because the halophosphates are not able to generate  that much or red, the colors requiring high red content become of lower CRI, as the color is made mainly by the orange-yellow component.
With the higher CCT "blackbody" the relative red content becomes lower (because of the higher content of the bluish parts), what means even when the halophosphates do not generate the red that much, it is not that much missing, hence the higher CRI of the colder CCT halophosphates compare to their lower CCT counterparts.

High CRI lighting:
For the 95+ you do not suffice just with the narrow peaks of the "tri-phosphors", filling the gaps become important as well. So many designs use the wide band halophosphate-like spectrum as the base and then supplement the sides (deep red,...) parts with the narrow band rare-earth phosphors to correct the defficiencies there.

And regarding the UV beads or so:
There the UV is supposed to do affect the body, so the effect is supposed to be under control (therefore the tight specifications on the spectrum variations and the seemingly short rated life and the penalties the saloons are getting from public health care agencies when not replacing the tubes within that limit). The normal lighting is supposed to serve long time, without such care, therefore it should not affect anby part of the body at all, so the UV limits for it are so strict. This is the main difference.
Now there is debate about the "full spectrum" lighting:
The proponents argue, with the common artificial light the UV exposure may become way too low, mainly w limited outdoor activities. So they want the UV limits to allow some radiation there.
The opponents argue, because it is artificial lighting, the exposure may easily become excessive, just because when it is installed as a lighting, the re is not much exposure control.
The authorities are more on the conservative side - once it physically affect the body, it must be kept under control as a health treatment equipment, requiring the equipment certification, enforcing the proper relamping at the rated EOL, regular inspections,... (there belong e.g. the tanning beads).
If the exposure is not controlled (you do not want to bother the operators with all the testing and inspections), there should be no physical effect at all, so the tight UV limits are in place.

So strictly speaking any offer of a "wide spectrum light with UV content" is in fact illegal: Either there is no UV content (so false advertisemsnt), or the UV exposure is above the limit (then it is not allowed to be offered for lighting fixtures).
And the legal problems with that is the main reason, why major makers do not offer such products at all.
And try to trust some obscure companies with your health...

Oops, I was thinking about specialized lamps, my reptile tube (for my collection) can get away with it because it's meant for reptiles, which need a lot of UV.
And this company seems to be a major one in the small world of reptile keeping. But then with these lamps, you would not need to worry about the UV, because the terrarium covers would block it, so you would not have to worry about it.
The problem with replacing this after 1 year is that the life can vary on how much you use it per day.

Usually specialty lamps such as reptile, bug zapper, etc have a one year replacement recommendation as that is what offers the best compromise between loss of UV (and light) output and the ideal situation. Although the lamp has plenty of life left after one year, the optimal desired output is considered to be less than acceptable so they recommend replacement. The same happens with standard fluorescent lamps but for general lighting it is less important so lamps are usually used until EOL occurs.

The problem with these is, if they loose their output power, you do not discover it until it is too late (the skin fungi progresses too much, so the reptile suffers).
Similar is the case for the germicidal lamps - if a sterilization relies on a given UV output, lowering that means the sterilization process is not working and so the diseases may start to spread uncontrollably. So there the rated life (replacement periods) are really in burning hours and are strictly enforced (by the supervisory authorities).
So if you need an UV source for your DYI resin hardening, an used germicidal lamp from a local hospital is the cheapest light source for you - as with the resin the underexposure is not as deadly as infection spreading in a hospital.

But why do they lose their UV output?
Is is because the phosphor is degrading?

The glass becomes more opaque to UV with lamp age.

The glass becomes more opaque to UV with lamp age.

Is there a transparent thing that does not do this to UV?

Apparently not any usable, otherwise it would be already used...
There is quartz, which (as far as I know) is more stable, but it is too hard to process for such large lamps.

There are just too many requirements for such tube:
- It should be able to reliably hold the vacuum (and the purity of the inner atmosphere)
- It should pass the energetic enough UV to reliably kill germs.
- But it should not pass the too short UV, as that would mean an excessive ozone generation and excessive corrosion of all the organic materials around (plastic, wood, fabrics,...), which is not desired at all. That would become harder with quartz
- It should be workable, so the resulting lamp will be strong enough (to not crack by itself,...) even with the rather thin walls (so the end pins within the fluorescent sockets will be able to support it's weight)
- It should not be excessively expensive, so even with the long life it would be way more expensive than replacing the worn out lamp each few 100's hours (together with the above, that practically excludes quartz)

And don't forget, because it is a medical equipment with a health risk in case it fails (the germs spreading), each design is subjected to certification procedure, which is quite expensive. Of course, the sales of such product should justify that. Because already with present lamps this is quite major part of all the expenses the maker has to spend to allow the use in hospitals, longer life would mean less of them sold, so these expenses will be way less "diluted" (a lamp with double life would have to have that development cost contributor double). Plus because e.g. quartz would be way harder to process, it would most likely require more iterations, include the efficiency certification (the reason will be, the users will find the tube too fragile, so need for a design change, but that means redo many of the expensive tests), which will make the development cost soaring too high.
Plus if the desired operational life would be longer, the tests would be longer (so more expensive; to prove the lamp is still efficient over that rating) as well. I would not be that much surprised, if this would not be the only factor limiting the rated life (longer, so more expensive testing would never pay off)
What I'm sure, with all the complications the present life rating is quite an optimum if speaking about the total cost of a single hour of operation.

For non-germicidal lamps like these, Quartz cannot be used because the Quartz would pass the UVC.