  The effects of oxygen mole fraction on the static properties of
pressure-sensitive paint (PSP) were investigated. Sample coupon tests using a
calibration chamber were conducted for polymer-based PSP (PHFIPM-PSP),
polymer/ceramic PSP (PC-PSP), and anodized-aluminium PSP (AA-PSP). The oxygen
mole fraction was set to be between 0.1-100% and the ambient pressure was set
to be between 0.5-140 kPa. The localized Stern-Volmer coefficient $B_{\rm
local}$ once increases and then decreases as the oxygen mole fraction
increases. The value of $B_{\rm local}$ depends on both ambient pressure and
oxygen mole fraction, but the effect of this parameter can be characterized as
a function of the partial pressure of oxygen. The value of $B_{\rm local}$ of
AA-PSP and PHFIPM-PSP, which are low-pressure type and relatively low-pressure
type PSP, have a peak at the relatively low partial pressure of oxygen, and
$B_{\rm local}$ of PC-PSP, which are atmospheric pressure type PSP, has a peak
at the relatively high partial pressure of oxygen. The peak of the intensity
change with respect to pressure fluctuation proportional to the ambient
pressure $S_{\mathcal{PR}}$ appears at the lower partial pressure of oxygen
than that of $B_{\rm local}$. This is because the intensity of PSP becomes
quite low at the high partial pressure of oxygen even if $B_{\rm local}$ is
higher. Hence, an optimal partial oxygen mole fraction exists depending on the
type of PSP and ambient pressure range of the experiment, and its optimal value
can be found based on the partial pressure of oxygen.
