Accession Number : AD0677127

Title :   A SYSTEM FOR RECORDING TEMPERATURES IN THE VICINITY OF LIQUID SURFACES,

Corporate Author : DEFENCE RESEARCH ESTABLISHMENT TORONTO DOWNSVIEW (ONTARIO)

Personal Author(s) : Kuehn,L. A. ; Weaver,R. S.

Report Date : 13 MAR 1968

Pagination or Media Count : 3

Abstract : An apparatus is described for measuring and plotting automatically the temperature distribution in the vicinity of an evaporating liquid surface, with a precision of plus or minus 0.01 degC. It consists of a thermistor, which forms one arm of an unbalanced Wheatstone bridge, a mechanism to lower the thermistor vertically through the surface and a coupled voltage divider to monitor its position. The outputs of the voltage divider and the bridge are connected respectively to the X and Y axes of an XY recorder to produce a graph of temperature against thermistor position. Experiments with water evaporating under the atmospheric conditions of 65% relative humidity and 21C temperature indicate that a temperature depression of 0.83 plus or minus 0.04 degC exists at the surface. (Author)

Descriptors :   (*LIQUIDS, *THERMISTORS), SURFACE PROPERTIES, TEMPERATURE, EVAPORATION, PLOTTERS, THERMOMETERS, CANADA

Subject Categories : Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE