中文摘要：

本文研制了一套高精度的金属振动管密度计，测量不确定度小于±0．5kg／m^3。用新研制的密度计，对233．15～323．15K温度区间内的二甲醚饱和液相密度进行了实验研究，实验结果最大相对扩展不确定度为0．34％（包含因子k=2）。利用本文实验数据和文献数据拟合了一个新的二甲醚饱和密度方程，新方程和实验数据的平均和最大相对偏差分别为0．13％和0．37％，可以满足工程实际应用。

英文摘要：

A new vibrating tube densimeter was developed with a precision of better than ±0.5 kg/m^3. Using this apparatus, the saturation liquid density of dimethyl ether was measured from 233.15 K to 320.15 K, and the max relative expanded uncertainty was 0.34%（coverage factor k=2）. The experimental data of this work were correlated as a polynomial function of the temperature with the published data of our previous work. The average and maximum relative deviation were 0.13% and 0.37%, respectively.