  Magnetic field fluctuations in the solar wind are commonly observed to follow
a power law spectrum. Near proton-kinetic scales, a spectral break occurs which
is commonly interpreted as a transition to kinetic turbulence. However, this
transition is not yet entirely understood. By studying the scaling of the break
with various plasma properties, it may be possible to constrain the processes
leading to the onset of kinetic turbulence. Using data from Parker Solar Probe
(\textit{PSP}), we measure the proton scale break over a range of heliocentric
distances, enabling a measurement of the transition from inertial to kinetic
scale turbulence under various plasma conditions. We find that the break
frequency $f_b$ increases as the heliocentric distance $r$ decreases in the
slow solar wind following a power law $f_b\sim r^{-1.11}$. We also compare this
to the characteristic plasma ion scales to relate the break to the possible
physical mechanisms occurring at this scale. The ratio between $f_b$ and $f_c$,
the Doppler shifted ion cyclotron resonance scale, is approximately unity for
all plasma $\beta_p$. At high $\beta_p$ the ratio between $f_b$ and $f_\rho$,
the Doppler shifted gyroscale, is approximately unity; while at low $\beta_p$
the ratio between $f_b$ and $f_d$, the Doppler shifted proton-inertial length
is unity. Due to the large comparable Alfv\'en and solar wind speeds, we
analyze these results using both the standard and modified Taylor hypothesis,
demonstrating robust statistical results.
