421.33 kg/m³ Viscosity: 1.87e-5 Pa·s Thermal Conductivity: 0.189 W/(m·K)
Aris cross-checked the numbers against his manual calculations. They matched. Then he checked the valve's factory spec sheet, partially recovered from the corrupted file. The REFPROP numbers were within 0.02% of the original. nist refprop 9
NIST REFPROP 9 holds a special place in engineering history. It arrived during a transition period where computing power was finally sufficient to run full Helmholtz equations in real-time on a desktop PC. It democratized access to reference-quality data, moving it from national labs to small engineering firms. nist refprop 9