  1,2-Ethanediol, 1,2-propanediol and their aqueous solutions are widely used
as heat transfer fluids. Their thermal conductivity is a vital physical
property, yet there are only few reports in literature. In this paper, thermal
conductivity of binary aqueous solutions of the two glycols was measured using
the transient hot wire method at temperature from 253.15 K to 373.15 K at
atmospheric pressure. Measurement was made for six compositions over the entire
concentration range from 0 to 1 mole fraction of glycol, namely, 0.0, 0.2, 0.4,
0.6, 0.8, and 1.0 mole fraction of glycol. The uncertainties of temperature and
concentration measurement were estimated to be 0.01 K and 0.1 %, respectively.
The combined expanded uncertainty of thermal conductivity with a level of
confidence of 0.95 (k = 2) was 2 %. The second-order Scheff\'e polynomial was
used to correlate the temperature and composition dependence of the
experimental thermal conductivity, which was found to be in good agreement with
the experiment data from the present work and other reports.
