Re: Need Ozone

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "cougercat by way of Terry Fritz <twftesla-at-uswest-dot-net>" <felix1063-at-home-dot-com>

Hello All,

How is Ozone detected electronically now?  What is the actual
detector/sensor composed of?

--jeff


----- Original Message -----
From: "Tesla list" <tesla-at-pupman-dot-com>
To: <tesla-at-pupman-dot-com>
Sent: Monday, April 09, 2001 7:04 AM
Subject: Re: Need Ozone


> Original poster: "default by way of Terry Fritz <twftesla-at-uswest-dot-net>"
<moya-at-primus.ca>
>
> Hello Dr Cadd
>
> Thank you I will try this approach w/ the spiked salt solution may be this
> will provide enough sodium
> iodine for the reaction.
>
> As for the rubber test - This test is of particular interest to me since I
> might be able to monitor
> the increase or decrease of O3 %  by observing an accurate time exposure
> ratio if standards were used
> - If this works it might also be of interest to those experimenting with
> quenching methods to gauge
> the O3 %  w/ there new method.
>
> Cheers
>
> Tom
>
> Tesla list wrote:
>
> > Original poster: "Dr. Duncan Cadd by way of Terry Fritz
> <twftesla-at-uswest-dot-net>" <dunckx-at-freeuk-dot-com>
> >
> > Hi Tom, Ed, Jeff, All!
> >
> > >Same lack of resources - So I saturated a small amount of hot water
> > w/ salt
> > >i.e. ( .001%)
> > >sodium iodide an mixed it with starch - Nothing happened so I
> > thickened the
> > >solution w/ more
> > >starch nothing happened - Then I thin the solution w/ more sodium
> > iodide
> > >still nothing - Guess I
> > >need a more concentrated form of sodium iodide or blue paper for any
> > results.
> >
> > You may be right as this is indeed very dilute iodide - incidentally,
> > you didn't mention that you'd exposed this solution to ozone but I
> > assume you soaked a bit of paper in it and hung it up near a working
> > coil.  The iodide/starch alone will do nothing.  It needs the presence
> > of ozone to liberate elemental iodine from the iodide by oxidation of
> > the iodide ion, as per Jeff's original posting.  Then you get the
> > intense coloration with starch.  If you have any tincture of iodine in
> > your household medicine chest or first aid kit you'll see what I mean.
> > That ought to give an instant dark blue/black colour with starch.
> >
> > However, it may also be that the chloride ions or the anti-caking
> > agents in the salt are interfering with things, I seem to recall (from
> > inorganic chemistry a long time ago) that iodine can form a complex
> > with other halide ions.  If you do have some iodine tincture and you
> > do see the blue/black colour with starch, you might try spiking a
> > small quantity of tincture with salt solution and see if it still
> > works with the starch :-)  If it doesn't, you know what's going on!
> >
> > But the test Jeff posted does work, I can dimly remember doing this
> > over 25 years ago.  Perhaps for this purpose you really do need pure
> > (99%+) sodium or potassium iodide.  I don't know what degree of
> > success you are likely to have if you go asking for say an ounce of
> > this from your local chemist's shop.  If you tell them it's being used
> > to monitor for toxic levels of ozone they may be sympathetic ("health
> > & safety" is a great moral bludgeon phrase, cunningly wielded you can
> > extract almost anything from anybody.)  Of course, if the O3 test
> > strips you found on the web are cheap enough, that's obviously the way
> > to go,  but you may be faced with the situation that one box of test
> > strips only costs pennies, but there's a minimum order of $100, one
> > can but try.
> >
> > The other test used for ozone detection, though less sensitive and
> > less rapid than the above, was to stretch a very thin (paper thin)
> > piece of natural rubber tightly over a frame a couple of inches in
> > diameter and leave it where it would be exposed to the ozone.  O3
> > attacks the double bonds in the rubber to form molozonides and
> > ozonides plus their decomposition products, and it becomes at first
> > sticky, then very brittle and its transparency decreases, becoming
> > white and opaque, which effects are intensified when the bonds are
> > stressed.  Nitrogen oxides don't have this effect.  The thinner the
> > rubber film, the more sensitive this test is.  Before the invention of
> > direct reading ozone meters, this was used for occupational health and
> > atmospheric monitoring many years ago.
> >
> > Dunckx
>
>
>
>