SPONSORED CONTENT: 10 things AQMesh did first


AQMesh modules integrate the measurement of a wide range of air pollutant gases into a single device.

2022 marked 10 years of innovation and leadership from AQMesh. To highlight the group’s experience, continued forward-looking vision, and commitment to pushing the capabilities of small sensor systems, the company lists here the top 10 things AQMesh has first developed and refined since its commercial launch in 2012. .

1. IoT connectivity using mobile phone network: remote data for air quality monitoring by small sensors

AQMesh was the first small sensor manufacturer to take an IoT approach, using the mobile phone network to connect to the cloud, allowing remote access to data from individual measurement points. Until then, conventional equipment used loggers and other small sensor-based air quality measurement equipment that offered direct download or radio communication, often through a cluster of sensor nodes.

2. Integration of gas and particulate monitoring in one small sensor instrument
Since 2013, AQMesh pods have been able to monitor gases and particles in a single instrument. The compact pods continued to lead in terms of the wide range of measurements offered on a single unit: up to six gases among NO, NO2O3CO, SO2H2S, TVOC and CO2 as well as PM monitoring and options for noise and wind speed/direction. Pod pressure, relative humidity and temperature are all measured as standard. At the 2019 AIRLAB International Microsensor Challenge, AQMesh was recognized as the most accurate multi-parameter outdoor air quality monitor and was rated for the most pollutant measurements offered in a single system.

3. Mini optical particle counter, counting and sorting particles by size, for accuracy on all PM fractions
AQMesh’s in-house designed optical particle counter measures PM1, PM2.5, PM10, TPC and TSP particles (up to 30 microns). Its bespoke design uses a straight line between the sample inlet and the bench, which means that larger particles do not settle in a curved sample path, allowing complete capture of pollutants. Additionally, the OPC uses a pump instead of a fan, which produces a constant flow from inlet to sample measurement, and then ensures consistency of sample calculations – fans can cause voids that could interfere with flow and affect sample measurement. The AQMesh OPC therefore makes it possible to accurately measure more coarse particles (PM10) in the sample.

4. Pioneers of small, city-wide sensor networks, from Citi-Sense to the Breathe London Pilot
Launched in 2012, AQMesh was part of the EU-funded consortium that set up a groundbreaking project to advise citizens on air quality, in eight cities, using hundreds of measuring devices. The Breathe London pilot, which ran from 2018 to 2020 and in which 100 AQMesh pods were used, was the world’s first hyperlocal surveillance network. The two-year pilot project proved and validated small sensors for city-wide monitoring, and also led the Environmental Defense Fund (EDF) to release a “model” for other cities. .

5. Out-of-the-box real-time accuracy with correction for environmental conditions and cross-gas effects without the need for machine learning
AQMesh’s high accuracy and performance has been achieved through years of extensive global colocation comparison testing against certified reference equipment, in all seasons, meaning AQMesh can perform accurately in the widest possible range of environments and conditions. No other manufacturer has access to the wealth of data collected by AQMesh. With these datasets, AQMesh was able to develop significant correction for cross gas effects and interference from environmental conditions through its fully traceable data processing algorithms.

6. Gold Pod Approach
The “gold pod” approach, as originally described by the AQMesh team, involves a unit being co-located and scaled relative to a maintained reference station, then moved around a network nodes to calibrate each of the other units. This method has now been widely adopted and provides an effective way to improve accuracy and ensure traceability. It was in 2017, when Professor Rod Jones from the University of Cambridge presented the results of the “gold pod” approach in which 20 AQMesh pods were deployed across Cambridge after co-locating one with reference , and he commented at the time “Because we know that all pods have the same reading and because we have a comparison between a pod and a reference instrument, we can say that all pods perform equivalently in all the city.

7. White reflective sun visor and insulation for temperature management
The sunshade was first added to AQMesh modules in 2013 to minimize the impact of direct sunlight on the module sensors. Various solutions were tested – for active or passive cooling – and AQMesh’s reflective shield, insulation and airflow space were found to be the most effective in minimizing the temperature stability challenge due to strong and direct sunlight.

8. Promote rigorous QA/QC and provide feasible methods to achieve it
Since 2015, the AQMesh on-site benchmark station means that every sensor has been tested through a rigorous quality control process before leaving the UK factory. The custom-built enclosure uses temperature-controlled reference/equivalence analyzers sampling air from an ambient cage that holds up to 100 AQMesh pods at a time. This ambient characterization during manufacturing is part of a rigorous AQMesh quality assurance process, which also includes strict criteria for PM, so every AQMesh pod in the field to date has been subjected to quality control measures. quality specifications to ensure the efficiency and reliability of each sensor under real-world conditions. QA/QC doesn’t stop at the factory either; the AQMesh team regularly offers remote QA/QC of the data once the pods are in the field.

9. Profiling of CO2 emissions
AQMesh can offer incredibly high out-of-the-box accuracy (typically less than 15% uncertainty) for CO2 monitoring. Using this reliable data, AQMesh can be used for CO2 source breakdown and measurement alongside NO and NO2 can help determine emission profiles for different locations. This means that combustion contributing to pollution can be specifically identified; for example whether there is gas or diesel, which is only possible with such precise data.

10. Long distance scaling
The Breathe London pilot showed how pods could be deployed in a traceable way across a city, using a new approach developed by partners at the University of Cambridge. This technique, which reduces the field requirements of the proven gold capsule approach, requires good quality baseline measurement data to be effective, and AQMesh built on the original Breathe London methodology with its own simplified long distance scaling tool.

For more information about AQMesh, contact them today or visit www.aqmesh.com.

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