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West, E. A.

Publications and source records attributed to West, E. A..

57 records · Page 4

Thermal diffusivity measurements of particulates using the differentiated line source

A method is described in which thermal diffusivity measurements can be made on particulate materials using the identical instrumentation as described in previous papers for measuring thermal conductivity. The measurements for the two properties can be made simultaneously, thus eliminating the changes in conditions when they are made separately. This system has particular application for studies of simulated lunar, planetary, or asteroidal surfaces in which laboratory measurements can be correlated with astronomical observations of thermal inertia. A representative set of data is shown which gives thermal diffusivity and thermal conductivity measurements on a particulate basalt in which the values for each temperature were taken simultaneously. A value for specific heat is calculated for measurements taken at each temperature.

West, E. A.↗

A comparison of two transient methods of measuring thermal conductivity of particulate samples.

A comparison is made of the line source (LS) method and the differential line source (DLS) method of measuring thermal conductivity of particulate materials in vacuum. The DLS method requires more instrumentation in the measuring circuitry (an additional amplifier and a differentiating circuit), but since it does not require a stable temperature to initiate a test, it does not need a sample temperature control system. DLS tests can be taken as the temperature in the samples is rising from liquid nitrogen temperature to room temperature. This eliminates the practice of extrapolating thermal conductivity over this large temperature range. Also, the advantages of reduced test time, data reduction time, and small sample temperature rise enable the experimenter to take about 7-12 DLS tests in the time of 2 LS tests. Test data from the two methods agree very well.

Scott, R. W.↗