  We use Solar Dynamics Observatory (SDO)/Atmospheric Imaging Assembly (AIA)
data to reconstruct the plasma properties from differential emission measure
(DEM) analysis for a previously studied long-lived, low-latitude coronal hole
(CH) over its lifetime of ten solar rotations. We initially obtain a
non-isothermal DEM distribution with a dominant component centered around 0.9
MK and a secondary smaller component at 1.5 - 2.0 MK. We find that deconvolving
the data with the instrument point spread function (PSF) to account for
long-range scattered light reduces the secondary hot component. Using the 2012
Venus transit and a 2013 lunar eclipse to test the efficiency of this
deconvolution, significant amounts of residual stray light are found for the
occulted areas. Accounting for this stray light in the error budget of the
different AIA filters further reduces the secondary hot emission, yielding CH
DEM distributions that are close to isothermal with the main contribution
centered around 0.9 MK. Based on these DEMs, we analyze the evolution of the
emission measure (EM), density, and averaged temperature during the CH's
lifetime. We find that once the CH is clearly observed in EUV images, the bulk
of the CH plasma reveals a quite constant state, i.e. temperature and density
reveal no major changes, whereas the total CH area and the photospheric
magnetic fine structure inside the CH show a distinct evolutionary pattern.
These findings suggest that CH plasma properties are mostly "set" at the CH
formation or/and that all CHs have similar plasma properties.
