Got schooled back in the day and he's back for more, don't know why he does it to himself. Everything he spouts is like straight out of a gavita booklet, probably has dreams of being just like the Jair rep one day
"reflector losses aside" "some reflector losses" is far from the truth and has been documented in an intergrating sphere======fact
like I said back then, great marketing and exaggerated #s:
Originally Posted by
whazzup
Quote:
Originally Posted by
Beta Test Team
An interesting metric I came up with the other day that uses data from this thread is what I called reflector 'photosynthetic radiation efficiency.' This provides the relative percentage of PAR range umol/s that exit the reflector as compared to the PAR range umol/s that is emitted by the lamp.
Just divide the reflector's umol/s per joule in PAR range by the lamp's umol/s per joule in PAR range, and multiply by 100. The lamp's total output is often reported by the manufacturer, as total PPF, or PPF per watt.
I was a bit surprised to learn, for example, Gavita PRO DE 1000W HPS reflector has a photosynthetic radiation efficiency of about 81%, that is, about 19% of radiant PPF emitted by the lamp is absorbed by the reflector/fixture.
https://www.icmag.com/ic/showpost.ph...postcount=6837
It is an interesting measurement, but quite incorrect. What you are referring to is the light output ratio, also called LOR. The 81% is not correct. Send the fixture to a professional lighting company which has a large scale photogoniometer to get the correct results, instead of trying to integrate points on a grid. In fact it is a lot more, but you just can not measure that accurately with an integrated point measurement. Which btw is also discussed in the same paper.
The values are correct, they were measured by a 3rd party accredited lab using NIST certified integrating sphere (for lamp AND fixture irradiance measurements, separately) and the most current protocols. They were not created by "points on a grid."
Just because the values are not what you want to see doesn't mean they're not correct. You have serious biases, which is to be expected, as Gavita is your employer. But that doesn't mean what you're writing is accurate, in fact, it has been proven otherwise (see this thread).
If you have provable data (facts) to refute what I claimed, and can provide their source (not just the values), please post them.
And no, a photogoniometer is not better than using an integrating sphere to calculate that value.
Quote:
Originally Posted by
whazzup
It is interesting that you came across LOR "the other day" because that is what professional lighting companies work with and specify all day long. It shows how uninformed you are, and I see you are quoting every time from the same documents and source. As a scientist you should know that you can not rely on a single source.
I didn't "come across LOR the other day," because I thought it up the other day all by my lonesome. I never claimed it was a unique idea. And I have never heard of LOR until your post; I'm a scientist, not a light fixture manufacture.
The 81% value I listed is correct, no matter how much you want it not to be so. Unless you have facts, i.e. data, you can post to refute the claim.
The facts stand for themselves, see the data in this thread, or just use your biases and tell me I'm wrong.
Quote:
Originally Posted by
whazzup
LOR is the basis of reflector ratings as in efficiency. Then we haven really talked about spread and uniformity yet, or exit angle of the reflector, or light losses to the ceiling with open reflectors. We haven't talked about how the lamp temperature can influence the lamp voltage and the output of a lamp, and we certainly have not discussed yet why you should change your lamp at 4% depreciation, and not ten, because you are not growing tomatoes in a greenhouse but silver on a stick in a climate room.
And do you know why? Because most of those things are off topic. And yet, uniformity was already discussed, and it's been proven Gavita is lacking in uniformity.
Also, relamping at 4% deprecation sure sound like $$$ to your ears, doesn't it? You talk about photosynthetic efficiency as if it's the most important factor, and then suggest relamping like every 8,000 hours?! Okay, sure. For a large operation with thousands of lamps relamping that often is a financial non-starter.
http://www.lighting.philips.com/main...116_EU/product
To those reading, relamping at 90% (i.e. 10%) is fine, especially when a quantum sensor is used to ensure correct irradiance.
Quote:
You have a lot still to learn.
Look, you're mad that the facts don't equal Gavita's claims and marketing, I understand. But for a company and human (you) that doesn't even know what PPFD means, I think you're a pot calling the kettle black, my friend.
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Our main threads:
I like whazzup, helped me in the past and at least he knows when to shut up (never refuted the data )when he's wrong and defends gavita because HE WORKS FOR THEM. Not like our furry friend who still doesn't own a 1000w DE last I checked for the ultimate irony........just keeps spewing ppf/ppfd/leaf temps from the company's brochure, sad.
also stating to re-lamp a DE bulb at 4%(8000h) is a joke and shows their greed==== ROI on cobs/leds would be quick if that is the case. Including higher umol/j,/ppf/w,LER,QER, this is why the smart cats are in this section.......
time to head for the door and take the "DOERS" with you...........especially the one that compared cobs to driving hybrid cars!lol