Yes, I remember Dave Douthit. I did not always agree with his approaches to things, but he did have some interesting data. The indoor NH3 is not that hard to fathom. Most of your industrial cleaning solutions, especially for glass, have some ammonia in it, so PPB levels of NH3 are not unusual. If you are anywhere in the Midwest in the United States, anywhere from April to June, farmers are planting fields and most apply anhydrous ammonia during the process. I am betting Iowa is a whole lot higher in NH3 during that time than the PPB range. Doug Pauls Inge <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 10/21/2010 04:51 PM Please respond to Inge <[log in to unmask]> To [log in to unmask] cc Subject Re: [TN] Conformal Coating Board Edges "Second, how do you determine how harsh an environment has to be in order to coat the edges? " Dough Pauls Answer: Do you remember David Douthit? His definition of Harsh was environments that belong to the upper range of the values in the 'OUTDOOR' column. His work. There exist no true formulas, but the values below shall in principle be multiplied with Temperature, Time, barometric pressure and local weather conditions (sun radiation for example). We have in principle followed similar figures. Concentration of selected gaseous air constituents (ppb) in the United States. OUTDOOR O3 4-43 H2O2 10-30 SO2 1-65 H2S 0.7-24 NO2 9-78 HNO3 1-10 NH3 7-16 HCL 0.18-3 CL2 0.005-0.08 HCHO 4-15 HCOOH 4-20 INDOOR O3 3-30 H2O2 5 SO2 0.3-14 H2S 0.1-0.7 NO2 1-29 HNO3 3 NH3 13-259 HCL 0.05-0.18 CL2 0.001-0.005 HCHO 10 HCOOH 20 There is one thing I don't understand: NH3 up to 259 ppb indoor. Hope this gave you at least an idea. /Inge ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 ----------------------------------------------------- ______________________________________________________________________ This email has been scanned by the MessageLabs Email Security System. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------