Table 3.

Experimental (p, c, T, x) data in the vapor phase for a (0.49896 argon + 0.50104 carbon dioxide) mixture, relative deviations of the experimental data c_exp from speeds of sound c_EOS calculated with the EOS-CG equation of state of Gernert and Span [1], and the combined expanded uncertainty U_c (k = 2) of the speed-of-sound measurements are listed. The results for the non-radial mode f (1, 1) and the radial modes f (0, 3) and f (0, 4) are tabulated individually. p is the pressure and T is the temperature (ITS-90). The standard uncertainty in temperature was less than 20 mK, the standard uncertainty in pressure was (20·10⁻⁶·p + 0.15 kPa) for p < 5 MPa and (20·10⁻⁶·p + 1.0 kPa) for p > 5 MPa, and the standard uncertainty in mixture composition was 5.5·10⁻⁶ (mole fraction). Values written in italics indicate points that may have been affected by pre-condensation.

p/MPa	T/K	cexp/m s−1	$100\left(\frac{c_{exp}-c_{\text{EOS}}}{c_{\text{EOS}}}\right)$	Uc(c) c−1/%
	f (1, 1)
8.21626	274.997	253.759	−0.6346	0.0547
6.07333	274.991	258.012	−0.1916	0.0494
4.02321	274.990	263.855	−0.0277	0.0455
2.00644	275.002	270.444	0.0044	0.0429
	f (0, 3)
8.21534	274.997	254.183	−0.4691	0.0627
6.07286	274.991	257.986	−0.2021	0.0544
4.02293	274.990	263.909	−0.0076	0.0463
2.00627	275.001	270.593	0.0597	0.0482
	f (0, 4)
8.21531	274.997	254.168	−0.4748	0.0560
6.07288	274.991	257.961	−0.2119	0.0515
4.02295	274.991	263.924	−0.0020	0.0498
2.00629	275.003	270.607	0.0645	0.0699
	f (1, 1)
8.17071	299.845	275.134	−0.1017	0.0538
7.65893	299.956	275.437	−0.0597	0.0525
6.00792	299.948	276.819	0.0023	0.0488
4.02077	299.945	279.772	0.0286	0.0452
1.98696	299.945	283.785	−0.0009	0.0428
0.494360	299.948	287.266	−0.0138	0.0423
	f (0, 3)
8.17018	299.847	275.044	−0.1349	0.0580
7.65802	299.949	275.380	−0.0786	0.0542
6.00747	299.948	276.821	0.0025	0.0511
4.02049	299.946	279.838	0.0518	0.0465
1.98682	299.944	283.882	0.0332	0.0716
	f (0, 4)
8.17009	299.846	275.034	−0.1382	0.0613
7.65792	299.947	275.370	−0.0816	0.0540
6.00748	299.949	276.817	0.0010	0.0493
4.02050	299.946	279.824	0.0466	0.0513
1.98682	299.942	283.891	0.0368	0.0547
	f (1, 1)
7.29116	350.009	306.194	0.0556	0.0512
6.00259	350.009	305.940	0.0584	0.0484
4.00152	350.010	306.296	0.0419	0.0449
1.98998	350.009	307.457	0.0012	0.0426
0.487400	350.009	308.872	−0.0102	0.0423
	f (0, 3)
7.29063	350.007	306.257	0.0766	0.0724
6.00218	350.009	305.923	0.0526	0.0505
4.00125	350.010	306.393	0.0736	0.0476
1.98985	350.009	307.603	0.0486	0.0465
	f (0, 4)
7.29062	350.006	306.021	−0.0008	0.1029
6.00219	350.009	305.915	0.0499	0.0725
4.00125	350.009	306.374	0.0676	0.0479
1.98984	350.006	307.574	0.0398	0.0685
	f (1, 1)
7.41167	400.202	330.747	0.0241	0.0513
5.98076	400.197	329.733	0.0323	0.0481
4.00897	400.196	328.850	0.0238	0.0447
2.00091	400.193	328.524	−0.0083	0.0425
0.451922	400.202	328.787	−0.0042	0.0422
	f (0, 3)
7.41118	400.202	330.789	0.0369	0.0656
5.98038	400.197	329.824	0.0600	0.1462
4.00865	400.197	328.955	0.0556	0.0473
2.00079	400.193	328.688	0.0414	0.0522
	f (0, 4)
7.41101	400.200	330.819	0.0461	0.0624
5.98038	400.197	329.886	0.0790	0.0670
4.00866	400.197	329.017	0.0746	0.0545
2.00078	400.191	328.635	0.0257	0.0678
	f (1, 1)
7.26483	500.462	371.189	0.0079	0.0508
6.00866	500.462	369.692	0.0119	0.0481
4.00814	500.460	367.562	0.0030	0.0446
1.98838	500.459	365.732	−0.0241	0.0424
0.476588	500.502	364.753	−0.0093	0.0421
	f (0, 3)
7.26441	500.462	371.243	0.0227	0.0527
6.00831	500.459	369.746	0.0268	0.0571
4.00792	500.462	367.673	0.0331	0.0468
1.98827	500.457	365.882	0.0172	0.0907
	f (0, 4)
7.26437	500.462	371.283	0.0335	0.0543
6.00830	500.462	369.733	0.0230	0.1071
4.00791	500.461	367.608	0.0155	0.0734
1.98828	500.459	365.864	0.0121	0.1079