function [vf]=vf(T) 
  %fluid specific volume [m^3/kg] at T [celsius] 
 
 Tsat=[0:10:370,374.15];
  %saturation temperature in celsius

 vliq=1e-3*[1.0002,1.0004,1.0018,1.0044,1.0079,1.0121,1.0171,1.0228,1.0290,1.0359,1.0435,1.0515,1.0603,1.0697,1.0798,1.0906,1.1021,1.1144,1.1275,1.1415,1.1565,1.1726,1.1900,1.2087,1.2291,1.2512,1.2755,1.3023,1.3321,1.3655,1.4036,1.4475,1.4992,1.562,1.639,1.741,1.894,2.22,3.17];
  %saturated liquid specific volume in m^3/kg

vf=interp1(Tsat,vliq,T);