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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'>Thanks for the pointer. I will check them out.<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'>Regarding the ultrafine particles (UFP): I have been looking for a couple of years at equipment that might be able to cover the range from 3 nanometers (PM0.003) to PM2.5. From what I have learned it requires a train of 3 machines in a row to get something meaningfully accurate. It is not that there are machines which can do a section of that spectrum each, it is that a machine can tell us what the mass is, but not the size. Some can determine the size but not the mass or density. This is not a general agreement on whether the number of particles is more important than the total mass, though it seems to lean towards the number at the moment (because the mass is so small) but the arguments are shaky. Mass matters, it is just very small.<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'>A train of three machines that can report the mass and number costs about $80,000. That is too steep for most people. A whole SeTAR lab costs about $65,000 with a combustion analyser and optical particle counter. With a much better NDIR machine and a TEOM it costs about $105,000 with the different being almost entirely the two machines. A test-day would cost about $600/$1000 to perform.<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 issue of money, if overcome, is not the whole solution. Collecting and quantifying UFP on a mass basis is seriously difficult. In many countries there are only a few people who can consistently weigh a filter to within to 1 microgram or less. If we go for number of particles only, there are serious dilution issues because of the huge range to be covered – the SeTAR Lab setup can deal with a range of perhaps 2 million to 1. But it is going to struggle with getting 10 or 15 g/cubic metre smoke predictably down to <100,000 ultra-fine particles per cu cm from tens of billions.<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'>Stove emissions are about the hardest thing to quantify because it boils down to being able to measure anything anyone could burn. At least in industry people have a clue what they are burning from day to day.<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'>Regards<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'>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><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>Sounds great! I agree that light scattering is better for some uses although I have been rattled by certain stoves (mostly fan stoves) that had a lot of smaller PM that was missed by the laser.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>But for improving a stove I believe that light scattering is OK just not for comparing stoves with different types of fires.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>The big filters can be purchased from HI-Q Environmental Products Co. at <a href="http://www.HI-Q.net">www.HI-Q.net</a><o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>We are doing a lot of stove improving and, like you, I believe that the major reason for having emissions equipment is to get to better performance. Testing should not be a good in and of itself. There are too many serious problems needing to be addressed, as you say.<o:p></o:p></p></div><div><p class=MsoNormal><o:p> </o:p></p></div><div><p class=MsoNormal>All 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></body></html>