Re: Need Ozone

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

Original poster: "default by way of Terry Fritz <twftesla-at-uswest-dot-net>" <moya-at-primus.ca>

Hello Jeff  -  <http://www.dcordes.freeuk-dot-com/analyser.htm>Sensor Schematic  -
Not O3 but it must be very similar in the processing. 

Cheers 

Tom 

Tesla list wrote: 
>
> 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 
> > 
> > 
> > 
> >