THERMAL CONDUCTIVITY MEASUREMENT INSTRUMENTATION SYSTEM UTILIZING RESISTANCE BRIDGE

• Main Author: Michael George, Laurentius
• Format: Final Project
• Language: Indonesia
• Subjects: Fisika
• Online Access: https://digilib.itb.ac.id/gdl/view/46088
• Institution: Institut Teknologi Bandung

Thermal conductivity (????) is a measure of heat transfer ability of a material given a temperature difference between the two sides of the material. This physical property is an important parameter to evaluate the performance of thermoelectric. Steady-state method (absolute temperature) is one of few methods that can be used to measure thermal conductivity. In this research, a two-system thermometer ???? measurement instrumentation system that measures temperature difference using resistance temperature detector (RTD) within a resistance bridge (which also known as the Wheatstone bridge) has been developed. RTD was selected due to its better accuracy and linearity of the transfer function compared to thermocouple and thermistors. Moreover, optimization of maximum heater power (?????????????????????????,????????????) and measurement cycle duration (?????????????????????????) in ???? measurement that utilizes steady-state method (absolute temperature) is done. Data acquisition and processing are automatedly done by using a program which was made using LabVIEW software. In this research, measurement of a copper plate results ???? = 368,339 W m-1 K-1 with 6,152% error (???????????????? = 392,484 W m-1 K-1). In this measurement, the optimal ?????????????????????????,???????????? and ????????????????????????? is 0,3 W and 90 s consecutively. The difference between the measurement result and reference value are suspected due to the sample’s imperfection geometry, heat current loss (or also known as parasitic heat loss) which was not taken into account, and a difference between both RTD PT1000’s performance.