I agree with what has been said, but a further question - the discussion refers specifically to parasitic power, does the same not apply to powered networks? I had always assumed that it did, just that powered was faster, I am wrong here?
On 05/10/13 09:31, Colin Reese wrote: > Without comment on the details of this situation, that is not how > convection and conduction work. > > Convection is typically described by Newton's law of cooling: q=hA(T-Tamb) > Conductions is q=k*dT/dx ~k (Tsurf-Tamb)/dx > > Thus the heat transfer rate depends explicitly on the difference between > temperature of the surface and ambient. Think about it - if the room is > 100C, the heat transfer direction is reversed, not to mention the magnitude. > > C > > On 10/5/2013 01:16, Colin Law wrote: >> On 4 October 2013 20:28, Jan Kandziora <j...@gmx.de> wrote: >>> [snip] >>> In addition, >>> measuring low temperatures with parasite power is bad, as it heats the >>> sensor and thus, gives you slightly wrong temperature values. >> I don't understand why this is worse when measuring low temperatures >> than high. If measuring with parasitic power puts in a certain amount >> of power (say 10mW average for example) then I would have thought this >> would raise the temperature of the sensor by an amount depending on >> the thermal conductivity to the environment (say, 0.5 degree, for >> example). It should not depend on the absolute temperature. In other >> words it should raise the temperature by 0.5 degrees (or whatever the >> value is in any particular case) whether the ambient is -10C or +30C. >> >> Colin >> >> ------------------------------------------------------------------------------ >> October Webinars: Code for Performance >> Free Intel webinars can help you accelerate application performance. >> Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from >> the latest Intel processors and coprocessors. See abstracts and register > >> http://pubads.g.doubleclick.net/gampad/clk?id=60134791&iu=/4140/ostg.clktrk >> _______________________________________________ >> Owfs-developers mailing list >> Owfs-developers@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/owfs-developers >> > ------------------------------------------------------------------------------ > October Webinars: Code for Performance > Free Intel webinars can help you accelerate application performance. > Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from > the latest Intel processors and coprocessors. See abstracts and register > > http://pubads.g.doubleclick.net/gampad/clk?id=60134791&iu=/4140/ostg.clktrk > _______________________________________________ > Owfs-developers mailing list > Owfs-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/owfs-developers ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60134791&iu=/4140/ostg.clktrk _______________________________________________ Owfs-developers mailing list Owfs-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/owfs-developers
