<div>Dear Crispin,</div>
<div>the biological effect of CO is that it binds with the haemoglobin in our blood and forms a complex, which then cannot bind with oxygen. In binding with haemoglobin, CO is, I think, about 6 times as efective as oxygen. It is however a reversible reaction, so that expsure to oxygen restores the haemoglobin back to its natural state. However, the death of a person is not reversible. I can understand the point made by you that it is the ratio of CO to oxygen or CO to CO2 that really matters, but then one can devise a pair of paper strip indicators, one for CO and the other for CO2 and use them together. </div>
<div>Yours</div>
<div>A.D.Karve<br><br></div>
<div class="gmail_quote">On Sat, Oct 23, 2010 at 3:57 AM, Crispin Pemberton-Pigott <span dir="ltr"><<a href="mailto:crispinpigott@gmail.com">crispinpigott@gmail.com</a>></span> wrote:<br>
<blockquote style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex" class="gmail_quote">Dear Richard<br><br>"Whether acoustically powered or calibrated by other sensors, if such can be<br>used to calibrate for example, a type species of local plant(s), animal(s)<br>
or even simpler, a locally recipe of ordinary chemicals which react to<br>dangerous concentrations of CO ---as the on site indicator of CO<br>concentration, THATS what we are looking for."<br><br>I am afraid to say it is slightly more complicated than that and I should<br>
say something or people might run too far down a road leading to really bad<br>information.<br><br>The CO level in the emissions is not easy to quantify unless you know how<br>diluted it is. CO is not a danger on its own - it is the concentration of<br>
it when breathed that matters. By the time it is breathed, it has been<br>diluted. How diluted was it when all the gases were passing through the<br>stove (excess air)? How diluted was it before it was inhaled?<br><br>In order to make a meaningful statement about the relative danger from CO<br>
from a stove - before getting to the point of discussing the dilution<br>post-stove, we need to know either how efficiently the conversion from C to<br>CO2 was (which involves absolute measurements of both CO and CO2 while<br>
measuring the mass loss) or we need to know the CO and the dilution.<br><br>Worse, we have to know when the CO was emitted because for our purposes<br>(mostly biomass stoves) the CO emission varies considerably with time - big<br>
time. For a normal improved stove the range of concentration will be 20:1.<br><br>If you have a device that measures the CO level and dilution at one moment,<br>it tells you nothing about what it will be 10 or 20 minutes later - not even<br>
within 5% of value.<br><br>Even if you had a strip that changed colour slowly with exposure level and<br>you photographed it every few seconds and had the ability to decode the<br>colour to calculate the CO concentration get a rate of change up and down<br>
(at least a theoretically possible device) it would not tell you what the<br>dilution was and thus you still can't work out the total.<br><br>We need real time CO and O2, or CO and CO2 (from which the others can<br>reasonably be calculated).<br>
<br>Regards<br>Crispin<br><br>The world is getting rounder. Help defeat global rounding<br><a href="http://www.youtube.com/watch?v=AJJpkEARIwc&feature=player_embedded" target="_blank">http://www.youtube.com/watch?v=AJJpkEARIwc&feature=player_embedded</a><br>
<br><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br>Stoves mailing list<br><br>to UNSUBSCRIBE or Change your List Settings use the web page<br>
<a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a><br><br>for more Biomass Cooking Stoves, News and Information see our web site:<br>
<a href="http://www.bioenergylists.org/" target="_blank">http://www.bioenergylists.org/</a><br><a href="mailto:Stoves@lists.bioenergylists.org">Stoves@lists.bioenergylists.org</a><br><a href="http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org" target="_blank">http://lists.bioenergylists.org/mailman/listinfo/stoves_lists.bioenergylists.org</a><br>
</blockquote></div><br><br clear="all"><br>-- <br>***<br>Dr. A.D. Karve<br>President, Appropriate Rural Technology Institute (ARTI)<br><br>*Please change my email address in your records to: <a href="mailto:adkarve@gmail.com">adkarve@gmail.com</a> *<br>
<br><br><br>