Measurement and correlation of the (p,ρ,T) relation of liquid n-heptane, n-nonane, 2,4-dichlorotoluene, and bromobenzene in the temperature range from (233.15 to 473.15)K at pressures up to 30MPa for use as density reference liquids

Liquid densities of THF and excess volumes for the mixture with water in a wide temperature and pressure range

“…But above 398 K the experimental densities were lower than the calculated ones. The relatively high deviations were also noticed by Schilling et al [11]. They measured the densities of heptane with a single sinker densimeter.…”

Measurement and correlation of the (p,ρ,T) relation of liquid cyclohexane, toluene, and ethanol in the temperature range from 233.15 K to 473.15 K at pressures up to 30 MPa for use as density reference liquids

“…This densimeter was developed by Brachthäuser et al [7] in the early 1990s and several improvements were performed by Klimeck et al [8], Claus et al [9], and Schilling et al [4] in subsequent years; the apparatus was briefly described by Wagner et al [10,11] and Wagner and Kleinrahm [12]. The densimeter covers a technically and scientifically important region of the (p, q, T) surface of fluids, namely, a temperature range from 233 K to 523 K, a pressure range from 0.1 MPa to 30 MPa, and a density range from 2 kg Á m À3 to 2000 kg Á m À3 .…”

“…The densimeter covers a technically and scientifically important region of the (p, q, T) surface of fluids, namely, a temperature range from 233 K to 523 K, a pressure range from 0.1 MPa to 30 MPa, and a density range from 2 kg Á m À3 to 2000 kg Á m À3 . Since putting this densimeter into operation, comprehensive measurements on argon [8], nitrogen [8], methane [13], carbon dioxide [13], ethylene [9], ethane [9], sulphur hexafluoride [9], n-heptane [4], n-nonane [4], 2,4-dichchlorotoluene [4], and bromobenzene [4] have been performed. As the design of the singlesinker densimeter was already described in previous papers [7,8], only the measuring principle is briefly outlined here.…”

“…In contrast to our previous measurements [8,9,13] with a sinker of quartz-glass (V S % 26.5 cm 3 , m S % 60 g), now a new cylinder made of a silicon single-crystal was used as a sinker (V S % 26.3 cm 3 , m S % 61.2 g, q S % 2.3291 g Á cm 3 ). This sinker was installed in the course of our last project [4]. The main advantage of the new sinker is the small uncertainty of its volume of 0.0015% at reference conditions (T = 293.15 K, p = 0.1 MPa) and of less than 0.004% over the entire temperature and pressure range considered here [4,16].…”

“…This sinker was installed in the course of our last project [4]. The main advantage of the new sinker is the small uncertainty of its volume of 0.0015% at reference conditions (T = 293.15 K, p = 0.1 MPa) and of less than 0.004% over the entire temperature and pressure range considered here [4,16]. This single-sinker densimeter avoids most of the shortcomings of other methods of densimetry and enlarges the operational range of density measurements in reference quality up to higher temperatures and pressures.…”