Planning of Measurement Series for Thermodynamic Properties based on Optimal Experimental Design

Abstract

Decreasing the time required for accurate thermodynamic property measurements is extremely desirable for model development that can respond to the needs of science and industry within a short time frame. Here, we demonstrate the application of optimal experimental design to measurements of thermodynamic properties. The technique is exemplified using the fitting of a Schilling-type equation from published $(p, ρ, T)$-measurements of ethylene gylcol and propylene gylcol. The analysis shows that a fixed-exponent fit using $(p,T)$-measurements along the five most informative isotherms produces models of relative density errors comparable to those obtained using the data along all investigated isotherms, \ie, eight or nine. It is also argued that a calculation of optimal isotherms prior to the measurement series can further increase the precision at no additional experimental effort.