The idea is splendid. With a built in piece of thinfilm, you can do like
when you depress 'tara' on a balance. However, I doubt you can deponate
such a extremly thin layer of metal on a substrate, at least repeat it on
thousands of substates.I have been little involved in sputtering and vacuum
depostion, and one of my friends nearby is a professor in that technology.
I can ask him, if necessary. Or connect you and him together. He has been
in the game for decades. Moreover, I have a friend who is specialist on
laser range and atmosphere measurements. If he can't give advice, noone
can.
The attenuation and reflection curves for a given laser wavelength,
usually IR, will be quite different between those two candidates. 3D smoke
and 2D film. But, sure, one can solve anything.
Q: why do you not try these handhold particle counters that we use for
cleanrooms? I had an old one, will see if I threw it or not. They have
built-in reference. They have a very large sensitivity range. If I smoke ,
pass the airlock, take on my blue 'space overall' etc, the instrument will
beep because I breathe out smoke particles the first minute.
If you mean that every household shall have one, then forget it.
Inge
Inge
Inge
On 29 August 2013 11:10, Steven Creswick <[log in to unmask]> wrote:
> Raye - Excellent!
>
> Along that line, how about a neutral density filter that you can buy for
> photography work? Too dense?
>
> Possibly, just go out and photolightographically define whatever density
> you
> want on a glass wafer and have it diced into whatever size you needed? You
> could define sizes and density of 'particulates'.
>
> There should be many thin-film places that could make these up.
>
> Steve C
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Rivera, Raye
> Sent: Thursday, August 29, 2013 1:59 PM
> To: [log in to unmask]
> Subject: Re: [TN] Blowing Smoke
>
> If this is an optical detector, why do you need actual smoke? Put a piece
> of
> tinted plexiglass in the detector as a calibration standard in the field.
> You can figure out what density of particles it is equivalent to in a lab
> with a particle counter.
>
> Best regards,
> Raye Rivera
>
>
> QA Manager * Canoga Perkins * 818-678-3872 * [log in to unmask]
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer
> Sent: Thursday, August 29, 2013 10:35 AM
> To: [log in to unmask]
> Subject: Re: [TN] Blowing Smoke
>
> I think what I'm going to try next is two wirewound resistors glued
> together
> with some ceramic paste, or maybe just build a hammock between them with
> some aluminum foil. Then try a drop or two of the liquid they use on model
> trains to simulate smoke. If that doesn't get me anywhere, then maybe the
> heating element from an e-cigarette.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Creswick
> Sent: Thursday, August 29, 2013 1:17 PM
> To: [log in to unmask]
> Subject: Re: [TN] Blowing Smoke
>
> Wayne - agree. That's why I pointed you to Gentex. It's optical. Used to
> be that all commercial aircraft had these detectors from Gentex
>
> Steve C
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer
> Sent: Thursday, August 29, 2013 1:03 PM
> To: [log in to unmask]
> Subject: Re: [TN] Blowing Smoke
>
> In an ionization-based detection system (technically illegal in my
> application because of the radioactive source required), you can check
> sensitivity by looking at the leakage current through the ionization
> chamber. Most of these "in circuit test" systems simply put a resistor
> across the ionization chamber and measure the time it takes set off the
> alarm.
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Steven Creswick
> Sent: Thursday, August 29, 2013 12:51 PM
> To: [log in to unmask]
> Subject: Re: [TN] Blowing Smoke
>
> Wayne,
>
> That is a good point about the smoke detectors, since there are two types -
> the ionization types and the particulate types that work by scattering of
> light.
>
> Look at FAQ #3 at this site -
> http://www.gentex.com/fire-protection/technical-support
> It would appear that they have the calibration and degradation issues
> worked
> out. I may still know some people there, but not sure how much help that
> would be in this situation.
>
> We used to ignite a ribbon of Mg to coat the inside of an integrating
> sphere
> with white powder. If you can combust tiny performs of Mg, or nanofoil as
> someone else suggested, that seems like it might satisfy your combustion
> quantity issue - although may create another issue with transport and
> handling....
>
> Steve C
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer
> Sent: Thursday, August 29, 2013 12:33 PM
> To: [log in to unmask]
> Subject: Re: [TN] Blowing Smoke
>
> Hi Dennis-
>
> Yes, as you and Richard have pointed out, calibrating particle sensors is
> not un-mapped territory. The systems are accurate and worthy of
> withstanding the rigors of lawsuits.
>
> But we can all see that there is a huge gulf between that kind of
> calibration and the other end of the spectrum, such as seeing whether a
> smoke detector is working OK.
>
> Another point in that gulf is a counter designed to control a HEPA in a
> room
> where a person has allergies. For that, they don't use a laser for
> illuminating the particles, they just use an IR LED. Hence they don't know
> if they are looking at one giant particle or a bunch of tiny ones. But
> they
> actually appear to be useful anyway, and the cost for the sensor from
> DigiKey is $12. Sharp tells you right up front on the data sheet that the
> LED will fade over time, by as much as 50%, with a corresponding drop in
> sensitivity. Also, the calibration curves provided in the data sheet show
> a
> very wide range of "typical" calibration slopes.
>
> So my gut tells me there should be some way of making a repeatable
> experiment that could be used for comparing these cheap sensors to each
> other and to watch the degradation in performance vs. time. I need to
> vaporize a defined amount of material in a closed volume. Turns out to be
> more challenging than I thought! It seems the diffusion of the vaporized
> material is actually the easy part. Complete combustion of a defined
> amount
> of material is hard.
>
> Wayne
>
> From: Dennis Fritz [mailto:[log in to unmask]]
> Sent: Thursday, August 29, 2013 11:27 AM
> To: Wayne Thayer
> Subject: Re: [TN] Blowing Smoke
>
> Good luck on this one, especially the "The idea is a cheap sensor" part.
>
> Particle measurment in either air or liquid is pretty well developed. IEST
> is the standards organization and there are also IEC international
> regulations/certifications
>
> I googled "air particle counter calibration" and a lot of stuff came up -
> most all probably too complicated for what you need - "cheap". However,
> this link gives some background on your problem and a bit of "who certifies
> what".
>
>
> http://www.particle.com/wp-content/uploads/downloads/2012/02/WP-MET-ONE-ISO-
> 21501-Calibration-of-APC-from-Metrology-Perspective-US.pdf
>
> Good luck.
>
> -----Original Message-----
> From: Wayne Thayer <[log in to unmask]<mailto:[log in to unmask]>>
> To: TechNet <[log in to unmask]<mailto:[log in to unmask]>>
> Sent: Thu, Aug 29, 2013 10:06 am
> Subject: Re: [TN] Blowing Smoke
>
> To answer previous question:
>
>
>
> The idea is a cheap sensor. 3rd world homes are notoriously smoky due to
> the
>
> cooking fire and due to kerosene lamps. Most of the smoke is carbon.
> There
> are
>
> lots of ideas for improving these homes (like LED lights with solar
> rechargers)
>
> so we can "improve their lot" by making it more healthy for kids to study
> inside
>
> (or maybe so they can buy stuff on the internet?). Anyway, the aid groups
> want
>
> a way to see what the bang for buck is in improving the indoor environment,
> so
>
> they need a sensor. These sensors work by shining an LED or laser through
> an
>
> air stream, and measuring the amount of light which is reflected off-axis
> by
> the
>
> particulates in the air.
>
>
>
> How does the bicycle pump (actually I'm imagining a disposable plastic
> syringe)
>
> pick up a defined amount of cigarette smoke? Maybe arrange a fixture which
>
> leaves the cigarette burning and allows the smoke to just rise into the
> open
> end
>
> of the syringe for a set amount of time, then put the plunger in. Might
>
> work-cheap to try!
>
>
>
> As to the other suggestions, such as the nichrome wire, I keep coming back
> to
>
> needing some kind of heated basket so I can make sure I burn 100% of
> whatever I
>
> put in there. A circulating fan and Brownian motion should make the
> environment
>
> pretty uniform, although with the tests I've been doing, I get a spike with
> an
>
> exponential decay as the particles settle. Still, the interior of the 5
> gallon
>
> bucket appears pretty uniform, even though the peak duration is only about
> 40
>
> secs.
>
>
>
> Wayne
>
>
>
> From: Inge Hernefjord
> [mailto:[log in to unmask]<mailto:[log in to unmask]>]
>
> Sent: Thursday, August 29, 2013 4:45 AM
>
> To: TechNet E-Mail Forum; Wayne Thayer
>
> Subject: Re: [TN] Blowing Smoke
>
>
>
> Don't laugh now, I am serious. A kind of cycle pump, but with a very small
>
> diameter nozzle. Pull the handle and suck a second sniff of cigarett smoke,
>
> continue pulling handle until pump is filled with air/smoke mixture. Now
> press
>
> handle slowly and you get a constant stream of mixture. Simple and cheap.
> Guess
>
> the nozzle should be fractions of a millimeter.
>
>
>
> Inge
>
>
>
> On 28 August 2013 08:07, Wayne Thayer
> <[log in to unmask]<mailto:[log in to unmask]><mailto:
> [log in to unmask]
> om<mailto:[log in to unmask]>>>
>
> wrote:
>
> OK, here's another problem I've been playing with (although it has little
> to
> do
>
> with IPC mission, it might be related).
>
>
>
> I am trying to build a system for measuring airborne particulates for
>
> humanitarian organizations looking for inexpensive ways to measure/monitor
>
> indoor air quality. There are cheap sensors available which might do the
> job,
>
> but they would need periodic re-calibration.
>
>
>
> So I need a controlled, extremely small amount of smoke. At first, I
> thought
>
> this would be trivial: Find a cheap part at DigiKey and put too many watts
>
> through it. Way too much smoke and too little control. Then I tried
> burning
>
> thin wires. Too irregular because sometimes they incinerate completely and
>
> other times they find a tiny defect and just burn that until the wire stops
>
> conducting. Then I tried just heating the wire enough to burn off the
>
> insulation. Still too irregular! I did just a few experiments and got 30%
>
> variation.
>
>
>
> Now I'm starting to think maybe a tiny piece of paper on an automotive
> cigarette
>
> lighter. That's a lot of power to get that glowing, and it is not
> convenient to
>
> attach to. Any other ideas?
>
>
>
> Wayne
>
>
>
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