PρT and saturation properties of isopentane at T = (280–440) K and up to 200 MPa

• The pρT properties for isopentane were measured in the compressed liquid phase.
• A total of 167 points data were obtained from T = (280–440) K and (1–200) MPa.
• The data were compared with the available equation of state.
• The saturated vapour pressures and saturated liquid densities were determined based on the additional pρT property data.

We measured the PρT and saturation properties of isopentane within the temperature range of 280–440 K at pressures up to 200 MPa using a metal-bellows variable volumometer. The mass fraction purity of the isopentane sample was 0.998. The expanded uncertainties (k = 2) in the temperature, pressure, and density measurements were estimated to be less than 3 mK, 1.43 kPa − 0.2% (P ≦ 200 MPa), and 0.11%, respectively. In the region above 100 MPa at T = 280 K and 440 K, the uncertainty in the density measurement increased from 0.11% to 0.14% and 0.22%, respectively. Eleven PρT measurements were carried out at temperatures and pressures reported in the literature for comparison. Additionally, the results of the present measurements were compared with those of the available equation of state.