Thermal Conductivity Meter

Project Presentation (Fall 2025)

Engineering Report

IBB CapstoneDownload

Introduction

Thermal conductivity is the ability of a material to conduct or transfer heat. Measuring this property is important to understanding a material’s behavior in thermodynamic and heat transferring applications. The goal of this project is to create an economical system capable of measuring both liquids and solids to within 5% accuracy which can be used in the MET316LAB course.

The Thermal Conductivity Meter (TC Meter) will heat a sample through applying a specific amount of energy that resistively heats a thermistor. Using temperature measurements taken before and after the energy is applied, the TC meter will be able to calculate the thermal conductivity of the material.

  • Electrical System Design #1
  • Liquid Probe Design #1
  • Liquid Probe Design #2
  • Probe Mount Design #1
  • Probe Mount Design #2
Sample of vitrified material at the U.S. Department of Energy’s Office of River Protection, image from State of Washington Department of Ecology.

Personal Motivation

Energy-producing systems almost always involve components which create heat, and understanding the thermal properties of these materials is instrumental to engineering new, efficient energy systems. Whenever chemistry or electricity intersect with mechanical systems, thermal conductivity analyses can be applied and prove useful.

Practical Motivation

A thermal conductivity measurer is desired for the MET316LAB course. It would be used sparsely but would be an effective tool to illustrate thermal conductivity in a lab setting. Commercially available thermal conductivity measurement systems are typically large, complex, and expensive; all of which cannot be accommodated for within the lab scope and budget. Engineering a system which is compact, inexpensive, and easily upkept or upgraded would provide the lab with a learning resource and future students an opportunity to explore instrumentation.

Engineering Merit

The project revolves around accurately analyzing thermal conductivity, which is a property of Heat Transfer. The simplest method of finding thermal conductivity involves assuming the measured environment as a lumped system. To do so, the geometry and thermodynamic properties of the probes and samples will be considered and scaled to a lump-able size. Instrumentation will be used to display live temperature measurements which will be factored into calculating conductivity. The housing and structures which will unite the circuitry and probes will require Mechanics of Materials analysis to ensure the designs are sufficiently strong.

Measuring Thermal Conductivity

Thermal conductivity is the measure of a material’s ability to conduct heat. It can be calculated by dividing the length over which the heat travels through a sample by the product of the sample’s area and the temperature difference, and multiplying that by the total heat energy applied. Pictured to the left in Figure 16-5 is an example of a set-up to measure the thermal conductivity of a solid material. It uses the integrated form of Fourier’s law of thermal conduction equation. This form of the equation also assumes that the material is homogeneous and the heat flow takes place one-dimensionally with two end-points at constant temperatures.

Figure 16-5, Adapted from
Fundamentals of Thermo-Fluid
Sciences, Fifth Edition, by Cengel et al.,
2017, McGraw-Hill Education

Results

This is where the final results of this project will be found upon completion.