Temperature Sensing and Regulation in Experimental Physics with Specific Applicaitons

Abstract

This project is a support to the research being done currently by Dr. Fenner at Kalamazoo College. His experiment is a study of high frequency sound absorption in various mixtures of liquids. These studies are to be done at the critical point of the particular mixture, where the effect of the critical point on the absorption of sound will be observed. The critical point is determined by the particular concentration of the mixture, the pressure and the temperature. For Dr. Fenner's study, the pressure will be kept at atmospheric pressure and he will vary the concentration while holding the temperature constant. To do this, he needs very accurate temperature regulation because in theory the critical point occurs at a specific temperature, not a range of temperatures. There is not as much concern in knowing the absolute temperature, since the critical point temperatures of these liquids are already known. The goal of this project is to design and begin construction of a temperature regulation system and a temperature sensing system for the experiment. It was decided that this could be adequately done using a stirred water bath of about five gallons, heated electrically. The temperature of the experiment needs to be regulated to within one one-thousandth of a degree, while sensing the absolute temperature to within one one-hundredth of a degree. To do this would of course require calibration as well.