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</o:shapelayout></xml><![endif]--></head><body lang=EN-CA link=blue vlink=purple><div class=WordSection1><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Dear Dean<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>The filter is on the output of the Dusttrak DRX and is inside a canister. It has a 37mm filter and we have 5 canisters. It can be changed in a few seconds. There are apparently (not located yet) multiple sources for pre-weighed canisters that can be fitted that already have a filter inside and a total dry weight. All that one has to do is weigh the final result which is a pretty simple approach. I would like to do that wherever possible.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>For comparative testing we do not use the filters. At this time there is no requirement for absolute measurements (certification against a numerical target). It is planned that the Jakarta lab will have this capability. It requires far more cost per test to do certification and the things tested for will be limited as a result. A certification lab staff complement is higher and they spend about 20% of their time calibrating equipment. <o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Even for major expenses that are involved in programmes on the scale of thousands of stoves, relative performance against a local baseline is accepted. That by no means says the results are comparable across other methods. The readings are only as good as the equipment times the protocol times relevance to the local cultural practises.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Because of the fewness of the labs and the real need at this stage for real time measurement to assist product developers, it is likely we will got for real time measurements of PM into the future. The real time measurement of mass using for example a TEOM 1405 (oscillating microbalance) is a step up and fits well with the variable dilution system. They have a very high capacity for a short time blast of PM such as we get in stoves during ignition. For a 150 mg max unit we can increase the dilution to perhaps 100 or 200 then reduce it to 4 or 5. The combination of a TEOM and the current setup means we can decrease the dilution by a factor of 6.66 which is a big improvement in precision.<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>I say your new large filter at the GERES lab and it looks really good. It looks off-the-shelf with the PM10 impactor. Where do we get one?<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'>Thanks<br>Crispin<o:p></o:p></span></p><p class=MsoNormal><span style='font-size:11.0pt;font-family:"Calibri","sans-serif";color:#1F497D;mso-fareast-language:EN-US'><o:p> </o:p></span></p><p class=MsoNormal><b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'>From:</span></b><span lang=EN-US style='font-size:11.0pt;font-family:"Calibri","sans-serif"'> Stoves [mailto:stoves-bounces@lists.bioenergylists.org] <b>On Behalf Of </b>Dean Still<br><b>Sent:</b> Tuesday, August 27, 2013 1:13 PM<br><b>To:</b> Discussion of biomass cooking stoves<br><b>Subject:</b> Re: [Stoves] A photo of a lab test from Ulaanbaatar<o:p></o:p></span></p><p class=MsoNormal><o:p> </o:p></p><div><p class=MsoNormal>Dear Crispin,<o:p></o:p></p><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Is the PM measured using a pump and filter system? What diameter filter are you using?<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Best,<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>Dean<o:p></o:p></p></div></div><div><p class=MsoNormal style='margin-bottom:12.0pt'><o:p> </o:p></p><div><p class=MsoNormal>On Tue, Aug 27, 2013 at 8:41 AM, Crispin Pemberton-Pigott <<a href="mailto:crispinpigott@gmail.com" target="_blank">crispinpigott@gmail.com</a>> wrote:<o:p></o:p></p><blockquote style='border:none;border-left:solid #CCCCCC 1.0pt;padding:0mm 0mm 0mm 6.0pt;margin-left:4.8pt;margin-right:0mm'><div><div><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Dear Friends<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>I am circulating this as an into to the test methods applied in Mongolia (and other places). It is a pretty good example of what the main measurements look like.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The photo is of one of the two computer screens which side by side. On the top left is the Digital Scale Capture Tool (DSC) available for $50 once off payment to Jeremy <a href="mailto:fuzzychaos@gmail.com" target="_blank">fuzzychaos@gmail.com</a> (as a thank you).<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>On the left of the DSC screen is the mass from the scale per 10 seconds. On the right is the (approx) calculated power in kW reported per minute. The data is saved to disk each 10 seconds. Multiple copies of the DSC can be run at the same time, one for each scale used.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Below the numbers screen is the average kW plot so far in blue and the cumulative mass burned (also so far) curve in red.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Below that is the mass change detected by the scale per 10 seconds. The value is shifted by the wind and moving fuel but overall as time passes, the precision is high, about 1 part in 5000. The burn rate (green line) can be seen to be declining towards zero as the fire burns out. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>There are 4 gas readings. This is the minimum if you want PM from a fire. On the left is the CO2 level in the diluter. The other three are measured directly from the stack (or hood). The CO is the concentration in the chimney, in this case. The next CO2 is the CO2 in the chimney and is of course higher than the CO2 in the diluter. The ratio between them is the level of dilution, in this case it is 3.232:1. The PM measured in the diluter is multiplied by the number 3.232 to give the equivalent of the direct measure from the chimney (which might be too high to measure directly). The dilution is variable with the turn of a knob.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The O2 on the right is the O2 in the chimney. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Notice that the total of the O2 and CO2 on the right does not add up to 20.945%, the O2 concentration in the ambient air. This is because there is H2 burning (from the fuel) and being turned into H2O. That H2O is not measured on this screen and as you don’t know what it is looking at this picture, you can’t tell if the equipment is working perfectly or not. Maybe it is a measurement error, maybe it is diluted by water vapour (which it is).<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The CO is very low at 18 ppm. The value for EA is about 1.67 and Lambda is therefore 2.67. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>2.67 x 18 ppm = 30. So the CO(EF) is 30 ppm, meaning that if there was no dilution by air, the CO cell would read 30 instead of 18.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The CO/CO<sub>2</sub> ratio is 18/(6.730 x 10,000) = 0.0002674 or 0.0266% (very good).<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The ‘modified combustion efficiency’ is <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>6.73/(6.73+18/10,000) = 0.9997 = 99.97%<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The kW blue line for power is the running average from the beginning so the value 11kW refers to the whole test as a whole.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>The PM value will be multiplied again by Lambda (dilution) to get a PM2.5(EF) value. This is the rating that the stove gets. <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Quick review: PM reading x dilution in the diluter x dilution by excess air = emission factor value. This is later multiplied by the mass burned x the volume of gases produced by the fire based on the fuel analysis. The result is the mass of PM (and by the same method the CO and any other gas) emitted during the test.<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Because the data is collected in real time, the stove can be tuned to find the best operating parameters. Sections of the test can be analysed later to create a plot of how the heat transfer efficiency, for example, changes with power or fuel condition (etc).<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'> <o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'>Best regards<o:p></o:p></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#888888'>Crispin<o:p></o:p></span></p><p class=MsoNormal style='mso-margin-top-alt:auto;mso-margin-bottom-alt:auto'><span style='color:#888888'> <o:p></o:p></span></p></div></div><p class=MsoNormal style='margin-bottom:12.0pt'><br>_______________________________________________<br>Stoves mailing list<br><br>to Send a Message to the list, use the email address<br><a href="mailto:stoves@lists.bioenergylists.org">stoves@lists.bioenergylists.org</a><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://stoves.bioenergylists.org/" target="_blank">http://stoves.bioenergylists.org/</a><br><br><o:p></o:p></p></blockquote></div><p class=MsoNormal><o:p> </o:p></p></div></div></body></html>