- what's a quick way to verify UVC from germicidal lamp? - 7 Updates
- OP-AMP Long-Term Reliability - 9 Updates
| KC JONES <kcharlie@nowhere.net>: Jan 18 04:11PM -0500 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. However, I don't know if it still emits the germ killing UVC spectrum. What's a quick way I could tell for sure? Thanks. |
| John Robertson <spam@flippers.com>: Jan 18 02:08PM -0800 On 2020/01/18 1:11 p.m., KC JONES wrote: > years, but recently brought it out to sterilize a room where a person > had been sick. However, I don't know if it still emits the germ killing > UVC spectrum. What's a quick way I could tell for sure? Thanks. Inverse square law makes your idea not so practical, aside from the inherent dangers of exposure to raw UV light! Better to wash the room down with a disinfectant, or simply air it out for a while... If the person was very contagious then look up the procedures for dealing with that rather than making up your own potentially dangerous ones. John :-#(# |
| JBI <JBI@ez1.net>: Jan 19 01:54AM -0500 On 1/18/20 5:08 PM, John Robertson wrote: >> killing UVC spectrum. What's a quick way I could tell for sure? Thanks. > Inverse square law makes your idea not so practical, aside from the > inherent dangers of exposure to raw UV light! I'm well aware of this after having used such lamps in the past. > Better to wash the room down with a disinfectant, or simply air it out > for a while... The problem is that there are dogs and cats present and the room I want to sterilize is in a relative's house. They own the pets, but I haven't had a pet in over 40 years. If I were disinfecting my own room, I might use 70% iso rubbing alcohol in sprayer format or even a weak bleach solution, but animals pretty much rule out either chemical. At least with the lamp, there are no residuals other than perhaps weak ozone that can be aired out quickly. > If the person was very contagious then look up the procedures for > dealing with that rather than making up your own potentially dangerous > ones. Trying not to make this complicated. All I wanted to do was see if the lamp was in fact still producing the necessary UVC spectrum. Surely, there should be something on the market that perhaps fluoresces only when UVC illuminates it. Or something similar and relatively simple. |
| "pfjw@aol.com" <peterwieck33@gmail.com>: Jan 19 06:55AM -0800 a) Neither cats nor dogs are threatened by a low concentration of either bleach or isopropyl alcohol. b) Anything over 10% alcohol or 0.5% sodium hypochlorite is an effective germicide & viricide. c) Common 80-proof Vodka cut 4:1 is also very effective, and leaves no residue. With that in mind, and the exposure requirements for UV to be effective, you would be far better served to use an alcohol solution. Which has the additional virtue of being able to get behind and into cracks and corners where light will not. Do also research the viability of the infections involved over time, tolerance of temperature extremes, tolerance of humidity extremes and so forth. And, just for giggles, look up Hospital patient room discharge requirements. Peter Wieck Melrose Park, PA |
| amdx <nojunk@knology.net>: Jan 19 08:59AM -0600 On 1/18/2020 3:11 PM, KC JONES wrote: > years, but recently brought it out to sterilize a room where a person > had been sick. However, I don't know if it still emits the germ killing > UVC spectrum. 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. I did a little searching and didn't find anything in the way of UVC sensors. But maybe a way to back into it? Adafruit has a UV sensor that works from 240nm to 370nm for $6.50. Maybe buy a filter for UVA and UVB, to cover that sensor and see if it senses any UVC. OR buy a UVC sensor and flip flop covering and uncovering the sensor and see if you get a square wave output. Mikek |
| amdx <nojunk@knology.net>: Jan 19 09:01AM -0600 On 1/19/2020 8:59 AM, amdx wrote: > senses any UVC. OR buy a UVC sensor and flip flop covering and > uncovering the sensor and see if you get a square wave output. > Mikek I should have posted the sensor. > https://cdn-shop.adafruit.com/datasheets/1918guva.pdf and the adafruit pcb. |
| Ralph Mowery <rmowery28146@earthlink.net>: Jan 19 10:08AM -0500 In article <r00ufh$et2$1@dont-email.me>, JBI@ez1.net says... > lamp was in fact still producing the necessary UVC spectrum. Surely, > there should be something on the market that perhaps fluoresces only > when UVC illuminates it. Or something similar and relatively simple. Lots of cloth material made out of polyester that is white will have a chemical in it that glows under the UV light. Try taking several pieces of white clothing and even the white thread that some buttons are sewen on with will work. Where I worked making polyester sandoze was added to the material to make the whites even whiter. That glows under UV light. |
| Cursitor Doom <curd@notformail.com>: Jan 18 09:11PM Gentlemen, How reliable are the old 'tin-can' encapsulated op-amps from say 40 years ago? I'm talking about the ones that look like large transistors and have typically 8 leads in the TO5-8 package. I'm unable to provide a part number as these don't have one as such. Could be a 741 perhaps but I can't be certain. Are they known to fail? thanks. -- No deal? No problem! :-D |
| John Robertson <spam@flippers.com>: Jan 18 02:12PM -0800 On 2020/01/18 1:11 p.m., Cursitor Doom wrote: > a part number as these don't have one as such. Could be a 741 perhaps > but I can't be certain. Are they known to fail? > thanks. Many solid state devices from that era are still running. Physical damage (moisture working in via the leads) is one primary cause of failure. If the leads look good then chances are fairly good the device will work. I use lots of 30 to 40+ year old components all the time for servicing our classic arcade games. Most are perfectly good. Other than electrolytic capacitors...they definitely have a shelf life/best before date! John :-#)# -- (Please post followups or tech inquiries to the USENET newsgroup) John's Jukes Ltd. MOVED to #7 - 3979 Marine Way, Burnaby, BC, Canada V5J 5E3 (604)872-5757 (Pinballs, Jukes, Video Games) www.flippers.com "Old pinballers never die, they just flip out." |
| tabbypurr@gmail.com: Jan 18 03:02PM -0800 On Saturday, 18 January 2020 21:11:24 UTC, Cursitor Doom wrote: > a part number as these don't have one as such. Could be a 741 perhaps > but I can't be certain. Are they known to fail? > thanks. The problem components from that era are lytics of course and glob-top transistors. NT |
| Cursitor Doom <curd@notformail.com>: Jan 19 01:23AM >> but I can't be certain. Are they known to fail? >> thanks. >The problem components from that era are lytics of course and glob-top transistors. OK, I have to know.. "Glob-top"?? -- No deal? No problem! :-D |
| Cursitor Doom <curd@notformail.com>: Jan 19 01:26AM On Sat, 18 Jan 2020 14:12:19 -0800, John Robertson <spam@flippers.com> wrote: >damage (moisture working in via the leads) is one primary cause of >failure. If the leads look good then chances are fairly good the device >will work. No sign of corrosion at all on the leads. >I use lots of 30 to 40+ year old components all the time for servicing >our classic arcade games. Most are perfectly good. Other than >electrolytic capacitors. So do I. The question wasn't about NOS components, but components that have been in service for decades. -- No deal? No problem! :-D |
| Trevor Wilson <trevor@rageaudio.com.au>: Jan 19 12:32PM +1100 On 19/01/2020 8:11 am, Cursitor Doom wrote: > and have typically 8 leads in the TO5-8 package. I'm unable to provide > a part number as these don't have one as such. Could be a 741 perhaps > but I can't be certain. Are they known to fail? **No. Provided supply Voltages remain within the limits set by the manufacturer, metal can OP amps, transistors, etc are phenomenally reliable. For a long time, all MIL-spec semiconductors were metal can only. They might still be, but I doubt it. In the early days of plastic encapsulation, some problems were notable. Mostly with power devices. Things have improved markedly over the years, but you will likely never approach the reliability of a metal can device by using plastic. -- Trevor Wilson www.rageaudio.com.au |
| tabbypurr@gmail.com: Jan 18 07:35PM -0800 On Sunday, 19 January 2020 01:23:38 UTC, Cursitor Doom wrote: > >> thanks. > >The problem components from that era are lytics of course and glob-top transistors. > OK, I have to know.. "Glob-top"?? http://www.ichom.org/Overig-499982/Connectoren-schakelaars-kabels-FAIRCHILD-Glob-Top/ The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much. NT |
| John Robertson <spam@flippers.com>: Jan 18 11:04PM -0800 On 2020/01/18 5:26 p.m., Cursitor Doom wrote: >> electrolytic capacitors. > So do I. The question wasn't about NOS components, but components that > have been in service for decades. My first sentence in my first paragraph was my (getting tired of 'my') experience about original esolid state devices still running. Do please read what is written, I'm the only one here who is allowed to make the mistake of not reading entire posts before responding! John ;-#)# |
| Cursitor Doom <curd@notformail.com>: Jan 19 10:10AM >http://www.ichom.org/Overig-499982/Connectoren-schakelaars-kabels-FAIRCHILD-Glob-Top/ >The round top is an epoxy glob covering the die, which sits on the flat thick sheet material that holds the leads. 2 tone ones make this easy to see, all black ones not so much. Ah. Ok. I have a few hundred of those but some obscure part numbers and all PNP so are unlikely to be called into service here. :) -- No deal? No problem! :-D |
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