Lambda Transformation of LiquidHe4at High Pressures

Measurements are reported of the pressure coefficient ${\beta }_V={\left(\frac{\partial P}{\partial T}\right)}_V$ of ${\mathrm{He}}^4$ I and ${\mathrm{He}}^4$ II along the isochore which crosses the $\lambda$ line at $T_{\lambda }=1.7683\mathrm{}$ °K and $P_{\lambda }=29.56\mathrm{}$ atm, and of the compressibility $\rho {\kappa }_T={\left(\frac{\partial \rho }{\partial P}\right)}_T$ along the isotherm $T=1.7683\mathrm{}$ °K, the closest points being 2.5 μdeg, 50 μatm, and ${10}^{-7\mathrm{}}$ g/${\mathrm{cm}}^3$ from the lambda line in temperature, pressure, and density, respectively. The data are well represented by the equations: $\{\mathrm{He}\mathrm{II}: {\beta }_V=-14.22+3.54\mathrm{}{log}_{10}(T_{\lambda }-T), 2.4\times {10}^{-6\mathrm{}}\le T_{\lambda }-T\le 3\times {10}^{-3\mathrm{}}\}\{\mathrm{He}\mathrm{I}: {\beta }_V=9.00+7.50\mathrm{}{log}_{10}(T-T_{\lambda }), 2.5\times {10}^{-6\mathrm{}}\le T-T_{\lambda }\le 6\times {10}^{-3\mathrm{}}\}\{\mathrm{He}\mathrm{II}:{\left(\rho {\kappa }_T\right)}^{-1\mathrm{}}=1000.4+78.9\mathrm{}{log}_{10}({\rho }_{\lambda }-\rho ), {10}^{-7\mathrm{}}\le {\rho }_{\lambda }-\rho \le {10}^{-5\mathrm{}},\}\{\mathrm{He}\mathrm{I}:{\left(\rho {\kappa }_T\right)}^{-1\mathrm{}}=1675.0\mathrm{}\pm 167.2{log}_{10}(\rho -{\rho }_{\lambda }), {10}^{-7\mathrm{}}\le \rho -{\rho }_{\lambda }\le {10}^{-5\mathrm{}},\}$ where