THERMAL CONDUCTIVITY OF LIQUIDS: D2717
EXPLANATION
The thermal conductivity of a substance is a measure of the ability of that substance to transfer energy as heat in the absence of mass transport phenomena. It is used in engineering calculations that relate to the manner in which a given system can react to thermal stress. This test method is applicable to liquids that are:
(1) chemically compatabile with borosilicate glass and platinum,
(2) moderately transparent or absorbent to infrared radiation, and
(3) have a vapor pressure of less than 200 torr at the temperature of the test.
Materials that have vapor pressures up to 345 kPa absolute can be tested.
TEST SUMMARY
A thermal conductivity cell consisting of a straight, four-lead, platinum resistance thermometer element located concentrically in a long, small diameter, precision bore borosilicate glass tube is calibrated by accurate measurement of the cell dimensions and by determination of the temperature resistant properties of the platinum element. Thermal conductivity is determined by measurement of the temperature gradient produced across the liquid sample by a known amount of energy introduced into the cell by electrically heating the platinum element.
TEST PRECISION
Precision data are not yet available. However, preliminary estimate appears to be 10 % repeatability for the mean of the two results.
