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COVID-19 Emergency - Using UV Lamps to sanitize Face Masks overnight

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Zero999:

--- Quote from: taydin on March 19, 2020, 09:55:00 pm ---
--- Quote from: Zero999 on March 19, 2020, 09:35:14 pm ---The smell is due to ozone being produced when oxygen in the air is exposed to short UV wavelengths. Ozone is also an antiseptic so might be partly responsible for the sterilising effect of the lamp.

--- End quote ---

According to this only UV light with a wavelength less than 200 nm will create ozone. My lamp is the standard 254 nm germicidal lamp.

--- End quote ---
Some do. According to the link you've just posted:

--- Quote ---Most germicidal lamps, including those from UV Resources, are produced with doped quartz glass, which blocks the transmission of the 185nm ozone-producing wavelength. The doped quartz glass allows the 253.7nm radiation to pass through, but it blocks the 185nm wavelength from escaping. Therefore, germicidal lamps with doped glass CANNOT produce ozone.
--- End quote ---

Did you buy that lamp from UVR or was it from somewhere else? If it has a plain undoped quartz tube, then it will pass 185nm and produce ozone.

taydin:

--- Quote from: Zero999 on March 19, 2020, 09:59:46 pm ---Most germicidal lamps, including those from UV Resources, are produced with doped quartz glass, which blocks the transmission of the 185nm ozone-producing wavelength. The doped quartz glass allows the 253.7nm radiation to pass through, but it blocks the 185nm wavelength from escaping. Therefore, germicidal lamps with doped glass CANNOT produce ozone.

Did you buy that lamp from UVR or was it from somewhere else? If it has a plain undoped quartz tube, then it will pass 185nm and produce ozone.

--- End quote ---

It's not from UVR. It's a chinese product, LIGHTEX. Nothing shows up when I search for it, so can't tell its construction.

Zero999:

--- Quote from: taydin on March 19, 2020, 10:05:43 pm ---
--- Quote from: Zero999 on March 19, 2020, 09:59:46 pm ---
--- Quote ---Most germicidal lamps, including those from UV Resources, are produced with doped quartz glass, which blocks the transmission of the 185nm ozone-producing wavelength. The doped quartz glass allows the 253.7nm radiation to pass through, but it blocks the 185nm wavelength from escaping. Therefore, germicidal lamps with doped glass CANNOT produce ozone.
--- End quote ---

Did you buy that lamp from UVR or was it from somewhere else? If it has a plain undoped quartz tube, then it will pass 185nm and produce ozone.

--- End quote ---

It's not from UVR. It's a chinese product, LIGHTEX. Nothing shows up when I search for it, so can't tell its construction.

--- End quote ---
Then it probably does produce ozone, hence the smell. The air would have to be very dirty and polluted for reactions with sulphur to occur, so much so, the air would already be very smelly to start with.

james_s:
Even a lamp that does not produce much light of such short wavelength may still manage to create a bit of ozone, it can be smelled in extremely small concentrations. My hot tub has an ozone generator that uses a small UV tube which is made of quartz.

taydin:

--- Quote from: Zero999 on March 19, 2020, 10:59:12 pm ---Then it probably does produce ozone, hence the smell. The air would have to be very dirty and polluted for reactions with sulphur to occur, so much so, the air would already be very smelly to start with.

--- End quote ---

That makes sense. The smell wasn't like a foul odor that is typical of sulphur anyway, so it is probably ozone.

In an FAQ that I read it says that the ozone will help killing germs that are not in the direct light path, so the ozone will actually complement the UVC light.

https://www.americanultraviolet.com/uv-germicidal-solutions/faq-germicidal.cfml

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