DESENVOLVIMENTO DE UMA PLATAFORMA ELEVATÓRIA AUTOMÁTICA PARA POSICIONAMENTO DE AMOSTRAS NA ESPECTROSCOPIA DIELÉTRICA

Abstract

The measurement of the electrical permissiveness of material through the coaxial probe technique (dielectric spectroscopy), comprises positioning a sample in order to immerse the probe in a specific depth of a sample. As the equipment is very sensitive, it is necessary to carry out constant recalibration in the presence of small mechanical disturbances. Therefore, the project consists of the development of an automatic elevating platform to position the samples from a probe without manual contact by the operator, through a microcontroller servo-positioning system, optimizing the time of conducting data collection experiments in the laboratory. For this purpose, a pantographic table made of PVC sheets was developed and powered by a closed-loop tower pro MG995 servomotor through the Arduino Nano prototyping platform and an HC-SR04 ultrasonic distance sensor with ON-OFF control with 0.2cm dead band. Tests were carried out with reference values for both raising and lowering the platform, reaching 2% of the final value and remaining in this interval in approximately 38 seconds for rising and 33 seconds for lowering the platform. The developed platform can be built with more resistant materials in the future such as acrylic, for greater mechanical stability, in addition to using a precision digital caliper to improve the acquisition of the system's output signal.