versão impressa ISSN 1794-1237
TORRES, Robinson; ARNAU, Antonio; PERROT, Hubert e AEDO, José Edinson. ELECTRONIC SYSTEM FOR EXPERIMENTATION IN AC ELECTROGRAVIMETRY II: IMPLEMENTED DESIGN. Rev.EIA.Esc.Ing.Antioq [online]. 2007, n.7, pp. 63-73. ISSN 1794-1237.
A detailed description of the electronic system designed to improve the measurements in an experimental AC electrogravimetry setup is presented. This system is committed to acquire appropriated data for determining the Electrogravimetric Transfer Function (EGTF) and provide information regarding the mass transfer in an electrochemical cell in the AC Electrogravimetry Technique, but maintaining a good trade-off between the locking frequency bandwidth and the resolution in the frequency tracking, that is, enlarging the bandwidth of the system to follow signals with frequency as higher as 1 kHz, but maintaining an accurate and continuous tracking of this signal. The enlarged bandwidth allows the study of fast kinetic process in electrochemical applications and the continuous tracking let to achieve a precise measurement with good resolution rather than average frequency records obtained by conventional frequency meters. The system is based on an Analogue-Digital Phase Locked Loop (A-D PLL).
Palavras-chave : AC electrogravimetry; quartz crystal microbalance; phase locked loops; bandwidth-resolution trade-off; coarse and fine tuning.