KY Ted and Kurt and All: Okay the technical paper on Infrared Thermometer Use and Misuse is ready and online at my website. http://www.h-s.bz/images/Infrared_Therm ... ok_PDF.pdf It's an Adobe Acrobate PDF and at almost 4MB it may take a while for you dial-up guys to download, but I think it's worth the wait. The paper is 30 pages of text, photos, graphics, and charts. Hope it is useful to you. Please let me know if you have another use that I didn't cover. Sorry Chad I didn't put in anything about engine analysis (you're covered the subject very well), but I do use one for that too. One note if you intend to do engine analysis with an infrared thermometer in addition to home inspection, you may want one that has a higher measuring range. The Raytek MT4, the most popular model for home inspectors, only reads to 525 degrees F. When the engine is much above idle the exhaust manifold is hotter than 525. In addition to an MT4 I also have a Raytek Ranger ST60 which reads up to 1100 degrees and combined with its very narrow field of view it is quite useful for the analysis technicques that Chad described. John Wells HOUSE-SMART Inc.___We're Smarter About Houses [:-graduate] www.h-s.bz