On Mon, May 27, 2013 at 8:25 PM, Harry Veeder <hveeder...@gmail.com> wrote:
> > > On Mon, May 27, 2013 at 7:04 PM, Joshua Cude <joshua.c...@gmail.com>wrote: > >> On Mon, May 27, 2013 at 5:22 PM, Harry Veeder <hveeder...@gmail.com>wrote: >> >>> >>> >>> On Mon, May 27, 2013 at 5:44 PM, Joshua Cude <joshua.c...@gmail.com>wrote: >>> >>>> >>>> But we have no idea what the emissivity of the paint used in the >>>> December test was, nor whether it was wavelength dependent. There may be a >>>> paint for which an assumption of emissivity of 1 greatly overestimates the >>>> power. A few measurements could have excluded this possibility. >>>> >>>> >>> >>> >>> This book >>> >>> _Absorption and Scattering of Light by Small Particles_ >>> >>> says for a body to have an emissivity > 1 it can't be much bigger than >>> the wavelength it radiates. >>> >> >> >> >> I'm not suggesting emissivity greater than 1. I'm suggesting we don't >> know how the correction for a limited wavelength range goes for low >> emissivity (this could be answered with a bit of effort, or by an expert in >> the area), and more importantly, we don't know if the surface has a >> wavelength dependent emissivity, in which case, an assumption of unity >> could err on either side of the true value of the power depending on the >> particular dependence. >> > > > > If they take emissivity = 1 then they are assuming the worst value for > emissivity at all wavelengths. How will a lower emissivity in any > range lead to an over estimation of power? > > Harry > > Never mind. I see what you mean The power measurements are just as sloppy as the earlier ECat tests. I though it would be when I heard in April that they were measuring radiant power. Harry
