| Summary: | 碩士 === 長庚大學 === 機械工程研究所 === 86 === In order to measure the thermal conductivity of all types of insulation materials, especially for the cases that require in situation and nondestructive measurement,we developed a portable steady-state thermal conductivity measurement instrument. The principle of the apparatus is to establish a high constant temperature zone on oneside of the material under test and measure the temperature on the other side and the heat flux provided to maintain a steady state. From the temperature difference on both sides of the material, the heat flux, and the thickness of the material we can calculate
the equivalent thermal conductivity. The measurement process is controlled by a 8051 microcontroller that accepts input parameters, keeps the steady temperature of the high-temperature zone, measures the heat flux and the temperature required, calculates the thermal conductivity at different temperatures, and displays them on a LCD display. The heaters of the high -temperature zone is driven by means of PWM (Pulse Width Modulation) with Proportion feedback control. We use a piece of polystyrene whose thermal conductivity is known and measured by ITRI (Industrial Technology
Research Institute) to verify the newly developed apparatus.
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