Excimer lamps are a bit different. They seem to work by capacitance. That's a classic cold cathode mercury vapour tube, but quite a fat one compared to the usual ones with very thin tubes. The power supply is probably a Royer oscillator with two transistors, that produces a symmetrical output to avoid mercury migration in the tube. The little blue capacitor in series with the tube rations the amount of current through it.
Thanks for the additional details! you have become an expert on these lamps with your various tear downs. I was actually pretty impressed at how well these lamps work. I thought a battery powered UVC lamp as a gimmick, but it really does do what it says.
Thanks Clive, I got one of these small units for my fridge and cupboards, based on your knowledge that the LED ones are sketchy. Thanks also electronupdate.
I work in a bio-lab, just for future reference, Once you have your samples inside the growth medium you must flip the petri dish upside down so the lid is on the bottom. This is to prevent contamination from airborne particles and from the condensation that forms to interfere with colonial growth and distribution.
tablatronix it’s used for something we call ,,qualitative isolation method”. It is used for isolation of colonies if a lower population is needed. Having a lower population means the cells can separate enough on the growth medium and you will have a separation of species as a result. My English isn’t very good but this has good information: www.ncbi.nlm.nih.gov/pmc/articles/PMC4846335/
Not to be critical, but wasn’t his goal simply to see if something grew at all & what-if anything would happen when exposed to the light? If they were all kept equally sitting around and the results are different after the light, does that not make the case? Because they would’ve all had the same “whatever” growing, regardless of where it came from. Thus, after time, they’re contaminated w growth. The ones exposed to the light seemed to have very little, if any growth left. I’m not a scientist, it’s just what I think was what the gentleman was showing. Correct me if I’m wrong, I’m not 100% sure. That was the conclusion I drew from the video. 😊
The UVC may have been partially blocked by the plastic lids. It's easy to block, which is why the tube itself is made of a specialist Uviol glass like quartz.
That is the exact comment I was going to make. Please do the experiment without a top for the petri dishes exposed to the UV-C light. I did this with Agar media, and the UV-C petri dishes were totally clear. Thanks.
That's true, polycarbonate is opaque to UV. So if the point of a petri dish is to grow something and not kill it, a polycarbonate container would be best to protect from even stray UV. Most clear safety glasses are 100% UV blocking as well for the same reason, polycarbonate.
We don't get to see it on???? Anyway, I GUARANTEE that's not an excimer lamp. I've never seen excimer lamps used outside of very highly sophisticated and frankly still somewhat experimental UV sterilizer lamps usually in medical settings. Plus they're still very expensive. That's absolutely a mercury vapor lamp. There's also a WAAAYYYYYY easier and faster method to see if it's real, just see if it tans a green banana after a few minutes.
Doubtful result of this test. UVC cannot pass through most transparent materials such as normal plastics, glasses, flexiglas, and polycarbonate. It can pass only quartz.
If your petri dishes are not made of quartz glass, they block the UVC. That explains why you had the growth there. I see the result of performance as a fail.
great video as always, thank you for taking the time and sharing, coming from you I thought that we were going to see the insides of that ucontroller lol. is there a ink to purchase on ebay? Thanks again
electronupdate there’s more. They might have slightly different labels. The one you had is identical to the one I bought on Amazon. UVC-86 is all the box says. Under the #2 Quest it asks, “is it effective?”. The last sentence in the answer is hilarious. It says, “The charging design is convenient for the use of killing letters such as sheets and pillows of the wine shop during the travel”. Whatever THAT means! 😂That’s what rose my suspicions if it was legit or a fake. Thanks for the video. (And be very careful with your traveling wine shop pillows. You don’t want anything happening to those. Lol.)
Is there a simple way to know if a light is UV or just a purple light? I'm a simpleton but I wish to have tips so I can also safely serialize some stuff I have. Any ideas?
Yes, it's crude but a simple way to test. Use the lamp on a banana. After a few minutes (depends on the power of the lamp) the banana will have slight scorching on the surface of the peel. Cover part of the banana with tape so that you can see the differences. The time it takes depends on the lamp's power and the distance from source to banana. Should the scorching not occur then too much distance, enough time, or not not enough lamp power may be a factor - or- it's piece of junk. Good part, you can still eat the banana. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7lzq6LuVWH0.html
I'd probably run the lamp through a cycle or two around where you opened those Petri dishes, just in case anything growing in them happens to spread using spores. :/
If you can look at it and get headaches, it’s real. My work made a UVC tunnel for sterilization and I can’t walk by it with all the UVC light spilling out of it.
It's real. All of the mercury vapor UVC lamps (such as your lamp) are real. It's the UVC LED lamps that have many fakes. By the way, if it didn't work in your experiments, it's because you left the plastic lids on. Ordinary glasses and plastics have 100% UVC blocking. That's why ordinary glass is only used in UVA lamps to make fluorescent clothes glow at parties, but ordinary glass is NOT used in UVC lamps to kill germs. Those use quartz glass tubes, which pass UVC light. Your petri dish lids are plastic, which blocks 100% of your UVC light's output, making it LOOK like it's a fake lamp, to those who don't have the same scientific understanding I do. Please be more careful with your videos, or you may convince people without scientific knowledge not to trust lamps that they SHOULD trust. I can tell just by looking at your lamp in this video, without even testing it, that you have a real UVC lamp in this video.