South Coast Science - Model Praxis/OPCube - Urban Air Quality Monitoring System
The Praxis/OPCube is a small rugged device that measures both gas and particulate matter (pm1, pm2.5, pm10) and is an effective monitor for low-cost screening, construction dust and local authority investigations. The Praxis/OPCube uses Alphasense sensors throughout and can be supplied with one (soon to be two) of their standard A4 electrochemical gas or VOC sensors. Sensor data including temperature and humidity can be stored on the device or transmitted in real-time via the 4G modem to the South Coast Science cloud. Open-source device firmware is supplied for highly customisable sensing and analysis. To maximise ROI over the life of the instrument, upgrades to device firmware and diagnostics are supplied remotely (if South Coast Science data analytics is used).
Praxis/OPCube: air quality monitor
The South Coast Science Praxis/OPCube offers an out-of-the-box solution for urban air quality monitoring. The Praxis/OPCube answers both the challenge of capturing accurate data in variable climate conditions and the need for fine-grained air quality monitoring networks. South Coast Science has responded to the call for a gas and particulate monitor, suitable for roadside monitoring, environmental health and local authority investigations.
Indicative air quality monitoring in practice
- Alphasense optical particle counter (OPC-N3): PM 1, PM 2.5 and PM 10.
- Plus one of the following: CO, H2S, NO, NO2, O3, SO2, VOCs or CO2.
- High frequency sampling : up to 30 samples a minute.
- Up to 1 hour operation in event of external power loss.
- Enclosure designed for ultra-low noise and harsh climate.
- Ultra low noise sensing for gases (ppb) and particulates ( μ g/m 3 ).
- Support for multiple analysis techniques including any sampling rate and real-time access.
- High density air quality network using low-cost, individually baselined devices.
- Open source device firmware for highly customisable sensing, data delivery and analysis.
- Consistent device function within broad climate range (T/rH) and casing rating for hostile environments.
The OPCube’s big brother, the ‘Urban’ was designed in consultation with the UN Environment Program and where possible, its attributes have been carried over to make this another robust & simple to use product.
- One Alphasense electrochemical sensor, or PID for VOCs, or NDIR for CO 2.
- Ultra low-noise circuitry maximises repeatability of electrochemical sensing.
- Alphasense OPC-N3 particle counter, plus approximated readings up to 40 microns.
- Sensirion temperature and relative humidity sensor.
- Data correction refined through co-location with government reference equipment.
- Variable sampling rates with a frequency up to every two seconds.
- 4G mobile comms for real-time data delivery to the cloud.
- GPS / GLONASS receiver.
- Runs Debian Linux operating system for robust operation and ease of integration with other sensor systems.
- SAMA5D27 CPU.
- Real-time clock with battery backup. Time synchronisation is via GPS receiver, network time protocol or real-time clock, as available.
- Sense data messaging, control messaging and data storage using Amazon Web
- Services (AWS) or customer’s own infrastructure.
- Local microSD data storage.
- Wide DC power input from 7 to 24 Volts, lithium iron phosphate (LiFePO4) rechargeable backup battery ( > 1 hour operation).
- Environmental range from -40 to +50 C.
- Measures 154 x 154 x 130 mm.
- Weight 2 kg.