Purdue AirSense

Bridging the Gap between Air Pollution Data and the Purdue Community

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AQ Sensors

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Central Monitoring Station

Our Central Monitoring Station consists of the following lab-grade instruments: imgC
thermo instruments
Clockwise from top-left:
  1. Thermo Model 42C Trace Level Chemiluminescence NO-NO2-NOx Analyzer
  2. Thermo Model 48 GFC Ambient CO Analyzer
  3. Thermo Model 49C Ozone Analyzer
  4. Thermo Model 146C Dynamic Gas Calibrator

TEOM 1400a
TEOM Series 1400a Ambient Particulate Monitor

OPS and NanoScan
  1. TSI Optical Particle Sizer 3330 (left)
  2. TSI NanoScan SMPS Nanoparticle Sizer 3910 (right)

Our central monitoring station is located at:

Portable Sensor Module

AirSense Team has built an affordable air quality station that is much cheaper than traditional laboratory sensors and much compact in size. The mobile station uses AlphaSense sensors to measure ozone, CO, NOx, and particulate matters levels in ambient air. These sensors are connected to Raspberry PI control unit that stream the data in real-time to the project’s website. The sensors’ enclosure has two inlets one for gases sensors and the other inlet for OPC sensor due to different air temperature requirements. Because the OPC sensor work with air sample in a temperature range of -10 to 50ºC, its sample tubes are wrapped by heating sheets as heat source during cold days. However, the gases sensors will function perfectly with air sample of a temperature range of -30 to 40ºC, and no additional heating or cooling sources are needed. The small size of the enclosure, which is 10 x 10 inches, and the relative low cost will allow the production of multiple units that can be spread around a region to gain better coverage and much accurate understanding of the region air quality. Furthermore, the enclosure size will increase the potential applications of the sensors as they can be mounted on mobile objects such as city buses, airplanes, backpack, and bikes to observe air quality in different locations from several sources.

design
The design of our sensor module
design
The front view of the sensor module
design
The side view of the sensor module

Tips

Here you can find more websites that were helpful for the project:
    - Python wrapper for Alphasense OPC-N2: Github
    - Project involving Alphasense NO2-B4 sensors: Github
    - How to connect a DHT22 sensor with Thingspeak IoT, run script at startup, and setup a script to notify of IP changes: Hackster
    - How to connect a DST18B20 sensor: Adafruit

Other relevant articles:
    - Preventing multiple instances of a cron job. Benjamin Cane