Download Wireless Sensor Board for Measuring Air Pollution

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Wireless Sensor Board for Measuring
Air Pollution
Author: James Carrapetta
Introduction
Fresh breathing air has always been a basic requirement
for human beings, however with current global trends we
are beginning to lose this most basic privilege.
Air Pollution:
• Is responsible for 2.3% of Australian deaths each
year and costs the government of NSW an estimated
$4.7billion per year in health costs.
• Is the cause of more premature deaths in NSW each
year than car accidents
• Has the potential to cause adverse health effects
including:
• Respiratory Infections
• Heart Disease
• Lung Cancer
Current air quality monitoring systems are expensive
and far apart. With a more detailed recording and
monitoring system for air pollution, significant
improvements can be made to the general population’s
health and well being.
Concept
Supervisor: Dr Vijay Sivaraman
Sensors
The wireless sensor board uses metal
oxide semiconductor gas sensors. A
semiconductor material is heated and
when a gaseous pollutant is introduced
into the chamber, electrons are freed
from the semiconductor. This decreases
its effective resistance proportional to
the level of pollution. By measuring the
voltage at the output of the sensor, an
air pollution reading can be estimated.
Theses sensors are low cost, small and
require a simple external measuring
circuit.
Results
The wireless sensor board was attached externally to a car
with a commercially available GasAlertMicro 5 air monitor. The
car was then taken for a drive from Mosman across Sydney to
Padstow. Carbon Monoxide was measured by both devices
and then compared to approximations based on government
monitoring sites (red markers).
1. Mobile Sensor: measures air pollution while the user drives
2. Smart Phone: uploads samples via 3G network to server
3. Database server: stores and uses pollution data to
produce a pollution model for applications
4. Web interface: overlays pollution map and displays on
Google maps
Wireless Sensor Board
The wireless sensor board is completely mobile and can be
easily attached to the exterior of a car. The whole device
only measures 70mm x 120mm and takes air pollution
samples every 15 seconds.
The wireless sensor board can measure:
• Carbon Monoxide
• Nitrogen Dioxide
• Ozone
UNSW
Using Bluetooth these measurements are sent to a Smart
Phone within the car where both time and GPS coordinates
are recorded. These recordings are then sent to a server
via the 3G network. The wireless sensor board has been
carefully designed to allow production of multiple units,
each uniquely identified.
The wireless sensor board produced similar results to the
commercially available air monitor. When compared with the
estimation from the available government data, both devices
showed that the air pollution varies significantly between close
locations. This supports the need for a more detailed, mobile air
monitoring system examining pollution levels at more locations.
Conclusion
Currently the government has 12 fixed air monitoring stations
around Sydney, too few to accurately measure pollution levels
across Sydney. With the wireless sensor board in use, a more
precise air monitoring system can be used for various
applications. With this new system in action we can begin to
take the first steps to an improved and healthier world.
ENGINEERING @ UNSW