THERMAL CONDUCTIVITY MEASURING DEVICE
CWU MET Senior Project
The thermal conductivity measuring device is used to measure thermal conductivity of solids, liquids, and food products. Thermal conductivity is a material property that determines the rate at which heat disperses through a material. This determines how well insulation works, what materials are used as heat sinks and refrigeration, and how thoroughly food is cooked. The device measures thermal conductivity by heating up a thermistor bead using a high voltage current for a set duration and allowing the given heat to disperse; meeting the goal of designing a device that can easily measure the conductivity. Additional requirements of this device include weight, volume, test time, prep time, accuracy, and easily replaceable thermistors. Most importantly the device must measure with 95% accuracy. To accomplish these goals the measuring device utilizes DAQ NI modules and multiple electrical components to construct a successful instrumentation system. The circuitry is housed in 3D printed ABS plastic sized for handed held use. A puncturing piece made from stainless steel is used to puncture through food product. Methods used to create this device include 3D printing, circuitry construction, software construction, and machining. The thermal conductivity measuring device constructed exceeds all requirements and is a conventional method of measuring thermal conductivity.
THERMAL CONDUCTIVITY?
What is thermal conductivity? Thermal conductivity is the only material property responsible for the rate of heat transfer. This device allows for the testing of thermal conductivity. Better testing in thermal properties can help identify optimum materials for a heat transfer system. Heat transfer in aerospace, electrical components, HVAC, automobiles and most anything that has an engine is important. Optimizing heat transfer for these systems can reduce the power input into cool the system. This can make travel, heating, air conditioning, and many systems requiring heat transfer cheaper and more available. In addition, Thermal Conductivity is an important property of thermal fluid science. Thermal conductivity is the thermal diffusivity rate of a material. This determines insulation ratings, the temperatures and times we must cook our foods, how thoroughly something is heated and how much heat can transfer per second. This projects intent is to discover a way to measure this property.
