Machado, C; Gouveia, C; Ferreira, J; Kovacs, B; Jorge, P; Lopes, L;
Proceedings of IEEE Sensors
We present a new and versatile sensor platform to readout the response of sensitive colorimetric films. The platform is fully self-contained and based on a switched dual-wavelength scheme. After filtering and signal processing, the system is able to provide self-referenced measures of color intensity changes in the film, while being immune to noise sources such as ambient light and fluctuations in the power source and in the optical path. By controlling the power and the switching frequency between the two wavelengths it is possible to fine tune the output gain as well as the operational range of the sensor for a particular application, thus improving the signal conditioning. The platform uses a micro-controller that complements the analog circuit used to acquire the signal. The latter pre-amplifies, filters and conditions the signal, leaving the micro-controller free to perform sensor linearization and unit conversion. By changing the sensitive film and the wavelength of the light source it is possible to use this platform for a wide range of sensing applications. © 2014 IEEE.
Costa, R; Lopes, I; Machado, C; Cabral, JM;
SAFETY, RELIABILITY AND RISK ANALYSIS: BEYOND THE HORIZON
Organizations are increasingly seeking to improve their efficiency and effectiveness to obtain reliable and high quality product at a lower cost. To achieve this objective, the use of tools that facilitate the acquisition of knowledge about processes is a valuable support. In maintenance, recording data about corrective actions is essential to define proactive actions that aim to avoid or mitigate the effects of future failures. Several computer systems are commercially available for maintenance management. However, the degree of suitability of these systems is low, once they do not consider organizations particularities. This paper presents a computer system for collecting and analyzing data from the machines of the production lines of a semiconductor company. This project aims to provide the company with a tool adapted to its needs, able to perform a behavioral analysis of all the machines of the production lines based on the systematic record of failures occurrence and maintenance activities.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.