Emissivity of 100%? Black? ----- Original Message ----- From: "Brooke Clarke" To: Sent: Wednesday, May 23, 2007 12:46 PM Subject: [EE]: Cheap thermal imaging > Hi Vitaliy: > > I measured part temperatures some decades ago by using a Barnes Engineering IR > thermometer. It came with a microscope and read the temperature at a point > source. But you only get correct readings if the emissivity of the object is > 100%, i.e, if it's black. So shiny things like metal transistor packages need > to be painted flat black or you need to know what emissivity number to dial > into the Barnes instrument. > > I think you can now buy a reasonably low cost thermopile type IR thermometer > that has a narrow (maybe 10 deg) look angle (most of them are 1:1 angle types) > that could be rigged up to do a similar thing. Remember that the single pixel > will report the integral temperature of what it's seeing so you want it seeing > only the hot part and not any background that's cooler. > > There are also some line and small number of pixel (maybe 64) imaging chips > commonly used for robots and it may be that the view angle for one of these > pixels would be small enough to be useful. > > -- > Have Fun, > > Brooke Clarke > http://www.PRC68.com > http://www.precisionclock.com > > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist