Thermistor-Based Thermal Conductivity Measurement System

摘要

This report describes a patented method for using commercially availablethermistors to make in-situ thermal conductivity measurements with commonly available thermistors to make in-situ thermal conductivity measurements with commonly available electronic equipment such as digital voltmeters. The emphasis is on the use of a single thermistor to measure the thermal conductivity of soils. Calibration techniques are explained and examples provided. Limits on this technique are discussed, including measurement range, material grain size, the amount of material needed for a valid measurement, and temperature stability. Specific examples of the use of this technique are provided for thermal conductivity measurements of soils, building materials, and the sludges in a sewage treatment plant. Data analysis is provided, including a statistical approach to finding the thermal conductivity in large volumes of material. (R.H.)