| 摘要 |
<p>To measure the heat transfer coefficient of a sample, an element with temperature sensitive optical properties is placed in contact or implanted in the sample. The element is heated or cooled. The temperature difference between the element and the unheated sample and the rate of heating or cooling indicate the heat transfer coefficient of the sample. In one embodiment, the element is heated or cooled at a constant rate. The heat transfer coefficient of the sample is then inversely related to the difference in temperature between the element and the unheated sample. Alternatively, the element may be heated or cooled at such a rate that the temperature difference between the element and the unheated sample remains substantially constant. The heat transfer coefficient of the sample then varies directly with the rate of heating or cooling. The heat transfer coefficient of a sample is a measure of its composition and other physical properties. The composition of gasses, liquids, the presence of bubbles in a liquid, and fluid levels can be detected by the optical technique. Pressure and flow rates of fluids can also be detected. The technique can be used also to more accurately measure the thermal conductivity and temperature of small objects with small heat capacities.</p> |
