The dielectric relative permittivity and speed of sound were simultaneously measured for HFO-1123 and HCFO-1224yd(Z) in the gas phase by using a cylindrical acoustic-electromagnetic cavity resonator. The measurement data for HFO-1123 were obtained in the temperature range of 263 to 333 K and the pressure range of 50 to 520 kPa, and those for HCFO-1224yd(Z) were obtained in the temperature range of 303 to 353 K and the pressure range of 20 to 200 kPa. Both of the fractional standard uncertainties for the relative permittivity and speed of sound measurements were estimated to be typically smaller than 0.02% without taking the sample impurities into account. The dipole moment and density were derived from the relative permittivity data through the dielectric virial equation. Meanwhile, the isobaric heat capacity in the ideal gas state were also derived from the speed of sound data with the acoustic virial equation. The temperature correlations for the ideal gas heat capacities were formulated and compared with the estimated values by the atomic-group contribution methods. It was found from the comparison that the estimated ideal gas heat capacities differed from the present data by more than 2%.

使用圆柱声电磁腔谐振器同时测量了气相中HFO-1123和HCFO-1224yd（Z）的介电相对介电常数和声速。在263至333 K的温度范围和50至520 kPa的压力范围内获得HFO-1123的测量数据，在303至353 K的温度范围内获得HCFO-1224yd（Z）的测量数据。压力范围为20至200 kPa。在不考虑样品杂质的情况下，相对介电常数和声音测量速度的两个标准分数不确定度通常都小于0.02％。偶极矩和密度是通过介电病毒方程从相对介电常数数据得出的。与此同时，理想气体状态下的等压热容也可以通过声维式方程从声速数据得出。制定了理想气体热容量的温度相关性，并通过原子团贡献法将其与估算值进行了比较。通过比较发现，估计的理想气体热容量与当前数据相差超过2％。