Many small sensor air quality monitoring systems cannot reliably measure coarse particulate matter, or PM10, because of the technology they use. AQMesh’s proprietary optical particle counter (OPC) delivers high out-of-the-box accuracy across all key particle matter (PM) fractions thanks to its bespoke, in-house design. Measuring PM1, PM2.5, PM4, PM10, PM-Total (up to 30 microns) as well as Total Particle Count, the proven OPC uses the most direct path possible between the sample inlet and measurement chamber. This allows more coarse particles in the sample to be measured compared to off-the-shelf OPCs and nephelometers, where these particles can be deposited in a maze-like pattern before being measured.
Humidity-related challenges have also been addressed by the AQMesh team. In some areas of high relative humidity, certain types of particles can absorb moisture from the surrounding environment (known as deliquescence), which can make them appear larger in diameter and result in erroneous readings. In most cases AQMesh can detect when this is happening and add a flag to the data point, allowing for it to be easily identified, reviewed and redacted as part of a robust data QA/QC process. Additionally, the OPC used in AQMesh has the option to include a heated inlet, which dries the sample prior to measurement and further reduces the effects of deliquescence. This option results in less than 1% of the data points being flagged and ensuring more consistent data accuracy.
Other benefits of the AQMesh OPC include its reduced maintenance schedule compared to other sensors – there is no need to change any filters, making it the ideal solution for industrial applications where critical processes create higher levels of particle pollution. Active sampling is performed with a pump instead of a fan, which means less turbulence in the measurement air flow and eliminates the opportunity for vacuums to affect the sampling accuracy. There is also no need to replace the whole OPC unit when it requires servicing – only the parts that need changing are replaced so the product remains sustainable whilst keeping the ongoing cost of ownership low. A silent pump will shortly be commercially available for indoor applications and already has orders to assist with clinical research for one of the UK’s leading research universities.
Customisable alerts for PM fractions, along with all other pollutants measured, are available to all AQMesh users. Email alerts can be set for exceedances on any channel and are completely customisable to individual detection limits. Where a pod is battery powered, alerts can also be set up to communicate the on-board battery voltage, triggering the battery replacement process in good time.
AQMesh prides itself on its accuracy and has always backed up its claims by publishing performance data online, making it easy for users to see real results, from real trials, in real world conditions. All AQMesh co-location comparison results can be viewed on the AQMesh website, alongside numerous independent and academic studies which verify AQMesh as a high-performing small sensor air quality monitoring system.