Table 4.

Experimental (p, c, T, x) data in the vapor phase for a (0.25019 argon + 0.74981 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. p is the pressure and T is the temperature (ITS-90). The results for the non-radial mode f (1, 1) and the radial modes f (0, 3) and f (0, 4) are tabulated individually. 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 4.4·10⁻⁶ (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)
5.50298	276.088	227.574	−0.4944	0.0500
5.39984	276.090	228.574	−0.4344	0.0497
5.29597	276.092	229.564	−0.3796	0.0494
4.99569	276.092	232.298	−0.2616	0.0486
4.00361	276.088	240.290	−0.1853	0.0464
1.99905	276.088	255.070	−0.0530	0.0431
0.501138	276.087	264.909	−0.0513	0.0424
	f (0, 3)
5.29545	276.092	229.019	−0.6179	0.0500
4.99521	276.092	231.832	−0.4635	0.0487
4.00324	276.089	240.293	−0.1854	0.0529
1.99889	276.089	255.172	−0.0137	0.1122
	f (0, 4)
5.50241	276.089	226.977	−0.7579	0.0500
5.39929	276.090	227.997	−0.6878	0.0496
5.29543	276.092	229.011	−0.6215	0.0494
4.99520	276.091	231.822	−0.4676	0.0497
4.00326	276.088	240.282	−0.1898	0.0489
1.99889	276.089	255.155	−0.0202	0.0495
	f (1, 1)
8.05744	290.014	227.741	−1.3363	0.0559
6.01266	290.008	240.255	−0.1374	0.0499
4.02345	290.007	251.638	−0.0931	0.0458
1.97901	290.009	263.297	−0.0460	0.0429
0.485294	290.008	271.437	−0.0459	0.0424
	f (0, 3)
8.05710	290.016	227.321	−1.5194	0.0598
6.01191	290.007	239.661	−0.3855	0.0501
4.02312	290.007	251.707	−0.0664	0.0718
1.97886	290.009	263.375	−0.0168	0.0609
	f (0, 4)
8.05704	290.015	227.350	−1.5069	0.0558
6.01213	290.008	239.669	−0.3822	0.0522
4.02313	290.007	251.647	−0.0903	0.0463
1.97886	290.009	263.408	−0.0041	0.0521
	f (1, 1)
8.06330	310.008	251.521	−0.2709	0.0541
6.00022	310.007	258.015	−0.0772	0.0491
4.02418	310.009	265.613	−0.0191	0.0454
1.98105	310.008	274.006	−0.0259	0.0428
0.488279	310.008	280.301	−0.0305	0.0423
	f (0, 3)
8.06271	310.010	251.514	−0.2752	0.0588
5.99962	310.005	258.004	−0.0818	0.0490
4.02386	310.008	265.675	0.0037	0.0550
1.98091	310.008	274.108	0.0110	0.0431
	f (0, 4)
8.06253	310.008	251.410	−0.3154	0.0552
5.99973	310.007	257.987	−0.0887	0.0496
4.02388	310.009	265.669	0.0011	0.0548
1.98091	310.009	274.122	0.0160	0.0451
	f (1, 1)
8.20098	350.013	282.123	−0.0345	0.0536
6.01823	350.011	284.804	−0.0003	0.0485
4.01058	350.011	288.505	0.0005	0.0449
1.98738	350.010	293.080	−0.0187	0.0426
0.500813	350.011	296.882	−0.0254	0.0422
	f (0, 3)
8.20028	350.013	282.089	−0.0464	0.0538
6.01776	350.011	284.820	0.0052	0.0492
4.01029	350.011	288.577	0.0255	0.0460
1.98725	350.010	293.211	0.0259	0.0591
	f (0, 4)
8.20027	350.013	282.078	−0.0503	0.0603
6.01776	350.011	284.806	0.0002	0.0632
4.01027	350.010	288.520	0.0056	0.1061
1.98726	350.010	293.128	−0.0026	0.0650
	f (1, 1)
7.95509	400.135	310.442	−0.0064	0.0526
6.01353	400.131	310.893	−0.0009	0.0483
4.01862	400.130	312.172	−0.0063	0.0448
1.98827	400.128	314.306	0.0106	0.0427
0.501932	400.127	316.145	−0.0232	0.0421
	f (0, 3)
7.95441	400.131	310.439	−0.0067	0.0531
6.01312	400.131	310.980	0.0269	0.0502
4.01835	400.130	312.301	0.0351	0.0464
1.98814	400.129	314.380	0.0339	0.0630
	f (0, 4)
7.95451	400.135	310.430	−0.0100	0.0701
6.01312	400.132	310.943	0.0152	0.0487
4.01835	400.130	312.247	0.0178	0.0729
1.98814	400.129	314.321	0.0153	0.0777
	f (1, 1)
8.00803	500.486	353.784	−0.0067	0.0525
6.00121	500.484	352.393	−0.0111	0.0481
4.01028	500.483	351.501	−0.0117	0.0446
2.00405	500.481	351.027	−0.0238	0.0424
0.501805	500.480	350.997	−0.0246	0.0421
	f (0, 3)
8.00752	500.486	353.817	0.0031	0.0539
6.00082	500.484	352.544	0.0318	0.0590
4.01003	500.483	351.639	0.0277	0.0481
2.00394	500.481	351.192	0.0233	0.0442
	f (0, 4)
8.00745	500.486	353.867	0.0170	0.0528
6.00081	500.484	352.488	0.0161	0.1095
4.01002	500.483	351.635	0.0266	0.0452
2.00394	500.481	351.234	0.0351	0.0499