Abstract
This article presents the details of design and development of a mobile and low-cost measuring device that can directly measure the thermal conductivity of a material. The device does not need an AC power source and needs only a battery to operate. In its operation, the output of a platinum resistance thermometer (PT100 sensor) is amplified by LM324 Quad differential input operational amplifier and fed to Microchip PIC16F877A microcontroller through an analog-to-digital converter. The microcontroller calculates the thermal conductivity of the material by a given set of temperature difference and finally the result is displayed on a liquid crystal display. PIC Basic programming language is used to program the PIC microcontroller. The analog circuit and printed circuit board layout are designed using OrCAD software. It has been observed that the proposed device can measure the temperature with an accuracy of 0.5 degrees C and thermal conductivity with an accuracy of 0.01 W/mm degrees C. The power consumption of the device is found to be 277.25 mW.