Artificial Perceptual Sensors - Artificial Human Sensors: Science and Applications - page 159

After receiving the sensor data, a complex data handling and organising, fol-
lowed by data analysis operations are performed and the outcome, i.e., a measured
value of the water quality, is presented. The communication to the user in this spe-
cific application is related to a traffic light concept, a green light indicating that
the water quality has not changed and a red light indicating a substantial change
in water quality has occurred. If needed a yellow light may indicate that a small
change has been detected, but in principle not in alarming amounts. In this context,
themeasuringprincipleregardingthewater quality can be seen as an electronic
tongue detecting, identifying and alarming exhibit an external structure of artifi-
cial tasting device with visual output properties. From the user's point of view,
the external tasting information is presented visually, by different colours, that in-
dicate three possible levels of drinking water quality.
The operational principles differ widely between the gustatory and auditory
measurement techniques. The design of an electronic nose concept is quite sim-
ple, when using commercial single sensor types that are carefully selected by its
selectivity to the measurable parameters we actually want to explore. By combin-
ing these single sensors in an array of other similar but complementary sensing
capabilities, the achievement experiences a complex system of locally gathered
sensors and constitutes as one overall sensor system device, however, with a cov-
eted multidimensional capability. The concept is usually built upon a loosely de-
fined parameter, as for example aiming to provide qualitatively measured values
of the air quality, which typically requires perceiving from many sensor elements
to capture the complex qualitative characteristics of a “true”, or at least expected,
definition of air quality. This approach also requires an analysing strategy, that
have to perform an experimental design process, to be able to define the concept

Figure 6.22. A single gas sensor from Figaro Engineering Company. Image courtesy of

Figaro Engineering Inc. c Figaro Engineering Inc. 2010. All rights reserved.