Resumen

GIMENEZ, J. F et al. Pampa III electronic nose: Control electronics design. An. Asoc. Quím. Argent. [online]. 2005, vol.93, n.1-3, pp.115-122. ISSN 0365-0375.

The Argentine electronic nose PAMPA III is an equipment operating with a measurement system based on a set of twelve solid state gas sensors implemented on thin films deposited on a MEMS (Micro-Electro-Mechanical Systems) type microheater. Solid state gas sensors were designed and built by the Institute LAMEL-CNR (Bologna, Italy) while the thin film sensors were made in Argentina in the frame of the cooperation project CITEFA-CNEA-FI (UBA). In this work, the operating principle of control drivers for PAMPA III sensors is reported, mainly considering the chosen criterion to control the power supplied to each sensor heater and the signal conditioning circuit related to the sensing film itself. The e-nose enables to program, in a flexible way, its functioning parameters, using control electronics and an associated software. Parameters to be changed are: heating power supplied to each sensor, bias voltage on each sensible film, velocity of the aspiration micropump etc. One of the main characteristics of the equipment is that the control circuits for sensors are of the "constant resistance" type. All measurements data of PAMPA III e-nose are supplied to a PC which performs the statistical processing, employing the pattern recognition algorithm of Principal Components Analysis (PCA).