On 2020/01/20 6:23 p.m., amdx wrote:
On 1/19/2020 9:01 AM, amdx wrote:
On 1/19/2020 8:59 AM, amdx wrote:
On 1/18/2020 3:11 PM, KC JONES wrote:
I've had a germicidal lamp more or less in storage for a number of
years, but recently brought it out to sterilize a room where a
person had been sick.Â* However, I don't know if it still emits the
germ killing UVC spectrum.Â* What's a quick way I could tell for
sure? Thanks.

I see UVC covers 200nm to 280nm. I don't know anything about UVC
bulbs so I need to ask is does yours have a specific wavelength
output? Like 270nm? My limited search finds bulbs of 254nm to 270 nm.
Â*Â*I did a little searching and didn't find anything in the way of UVC
sensors. But maybe a way to back into it?
Â*Â*Adafruit has a UV sensor that works from 240nm to 370nm for $6.50.
Maybe buy a filter for UVA and UVB, to cover that sensor and see if
it senses any UVC. OR buy a UVC sensor and flip flop covering and
uncovering the sensor and see if you get a square wave output.

Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Mikek

Â*Â*I should have posted the sensor.
https://cdn-shop.adafruit.com/datasheets/1918guva.pdf

Â*Â*and the adafruit pcb.

https://www.adafruit.com/product/191...An90EALw_ wcB




Â*No one has responded to my post. Is there anything fundamentally wrong
other than the cost of filters is high and the sensor has it weakest
response in the UVC wavelength.
Â*I don't mind the idea getting shot down, I'd learn something.

Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â*Â* Mikek

Hi Mikek,

While your information may be valid, it is of little use to the OP to
try to use a UV bulb to sterilize the room. It would be dangerous to his
eyes and or skin, and it would be ineffective as the UV only would
effect microbes that are on a surface the UV light would strike, plus
the UV light has to be near (under 1 foot typically) to have a high
enough concentration and it needs to light up the organisms for up to
five minutes to be sure of killing them. Thus you have to hold the UV
lamp for five minutes over every square inch of the room and you won't
get any of the crevasses at all!

So totally impractical.

On the other hand if you made a separate posting under the topic of
tools to measure UV bandwidth (or similar) you might get more bites!

John :-#)#