Each time we think we have found a spectacularly remote air quality monitoring location, an even more inaccessible spot is reported by one of our users.

Full-day trips to visit a location have now been beaten by customers who need to charter a plane to reach them. So, remote diagnostics and support are very important.

Luckily, IoT communications, cloud data management and over 10 years of experience supporting AQMesh have allowed us to continually improve our ability to supply and support AQMesh in remote locations. Pods have been used from the edges of the arctic to undeveloped deserts – as well as on ships – with the help of a few features.

Robust design, low maintenance intervals

AQMesh was designed to be rugged, for use all over the world and with an expected maintenance interval of two years. We have always understood that field maintenance requirements must be kept to a minimum, and pods operating for year after year, in the harshest environments – from deserts to extreme cold – demonstrate design effectiveness. This includes protecting electronics from the elements and mitigating electromagnetic interferences, as well as taking measures to keep insects, wildlife and birds out/off.  The unobtrusive pod design has also ensured a very low rate of vandalism and theft.

QA flags and notifications

The AQMesh data stream includes vital pieces of information which allow users and the AQMesh support team to check that pods are functioning correctly and provide an early warning system. Users can register for email notifications for their pods – it is always better to find out that power is running low or data is no longer being transmitted at the time, rather than when the project ends and it’s time to review data.

Remote scaling / calibration

Whilst AQMesh was a leader in co-location comparison and the ‘gold pod’ technique for in-field calibration, these approaches do require regular site visits to move pods around. We have now developed a method that can provide remote calibration of a sensor network, with or without an available reference station, that does not rely on artificial intelligence.

Diagnostic information

The AQMesh team can access additional diagnostic information remotely, such as performance indicators from the optical particle counter, solar pack battery voltage or sensor failures. Some of these indicators are available to users via their secure online or API access, and some can be used by our global technical support team. The team uses the full range of diagnostic information available, including SIM connection attempts, to provide free support for the life of the equipment. Their over-riding goal is to fix any problem without asking users to visit the site.

Over the wire intervention and updates

AQMesh firmware developments now allow power cycles to be triggered remotely, firmware to be updated over the wire or remote sampling and transmissions interval changed.

Power

We have learned from the many challenges that power supplies can present to remote operation. Whilst the original lithium thionyl chloride battery offered unbeaten long-term autonomous operation of gas sensors, increasing shipping limitations have turned our focus to direct power supply and solar. We invested in a full technical investigation to identify a mains to 12V DC transformer that could cope with ‘dirty’ power supplies, as well as in-pod measures to manage spiky or intermittent power.

Having seen so many problems from simple solar-panel-plus-battery arrangements, we designed our own smart solar pack, which squeezes the most power out of any location, manages power delivery and provides online voltage measurements. We are mindful that sampling and reading rates are defined by the project – and potentially certification – and the power supply must deliver the same sampling throughout the year. Readings should not be compromised by the difficulty of providing autonomous power.

Communications

The global SIM supplied with a standard AQMesh pod will roam across networks to find the best connection at each transmission, and has proven to be a very reliable way of transferring sensor output from hardware to our cloud server for over 10 years in more than 70 countries. Occasionally, we find that only a single, specific network is available – or a customer would prefer to use their own SIM – in which case we can programme the pod to work with a locally-sourced SIM contract. To achieve autonomous communication, the AQMesh LTE CAT M1 modem uses the latest LTE communications standard, including support for NB-IoT where available. In the most extreme cases, satellite communication is the only viable option and AQMesh can connect via an ethernet port to a suitable modem to connect this way. Reliable communications are key to remote data access and support.

The growing need for remote, long-term monitoring, in all conditions, drives our continuous development from data QA to comms, and we welcome challenges.

AQMesh small sensor air quality monitoring systems have been in use around the world for over a decade now, but it remains the case that support challenges are always greater with ..

• New customers, unfamiliar with the product
• Located a long way away (distance, time zones, business culture)
• In difficult conditions (environmental, infrastructure)
• With little or no knowledge of air quality monitoring
• Working at the end of a long chain of parties

Whilst any one of these points in itself makes user support harder, the AQMesh team have energetically pursued the ideal of providing great support, even when all five challenges apply.

To illustrate this point, we can tell the story of 16 pods used in Bangladesh, Pakistan, Vietnam, Philippines and Mongolia. AQMesh was chosen for this project, funded by an international bank, coordinated by an international consultancy and procured through a UK distributor. The pods were shipped in April 2020 all measuring PM and a combination of gases including NO2, O3, CO and SO2 using mains and solar power. Most pods were installed easily, as AQMesh is designed for quick installation, by simply connecting the power supply and using the standard fittings provided to mount to a post.

In November 2020 two pods in Philippines were reported as ‘dead on arrival’. As the cause for this failure could not be quickly established remotely or through the chain of communication, two new replacement pods were shipped and it was confirmed they were functioning normally as soon as they were installed. Inspection of the two returned ‘dead’ pods indicated that the pods had been internally re-configured since they left the factory: this sort of curiosity is not unknown, and it is rare that any party wishes to hold their hand up, so the issue was not pursued further and all of those involved in the project were happy to see all pods delivering data. In February 2021 it was agreed that AQMesh would take over direct support of the pods, as it streamlined support by no longer communicating via the UK distributor.

By April 2021 some sensors had been replaced under the no-quibble 12 month warranty and the AQMesh team was explaining why data is redacted in ‘extreme conditions’. Briefly, all electrochemical sensors produce less stable output when subjected to high temperature and low humidity, often showing artificially elevated readings. AQMesh identifies and flags data under such conditions and the default is to redact flagged data, which avoids likely over-reads being reported. Even in the most extreme global environments, redaction leaves data delivery well above the 90% target set for conventional air quality monitoring equipment.

In September 2022 the international consultancy confirmed that their project had finished. The only way the pods could continue being used in the countries was through direct support from AQMesh, so the chain of communication shortened further and AQMesh offered to continue to support the pods, using the free weekly data delivery service.

To date the AQMesh team still supports the pods, free of charge, and recently resolved communication problems with pods in Pakistan which had been caused by environmental debris blocking the solar panels used as the power supply. One pod is now being returned to factory to be investigated, repaired and returned to the user.

AQMesh has always prided itself on its customer service. There is no cost for technical support and location continues to prove it is not a barrier. A wealth of online training material is provided in addition to remote technical support and smart remote diagnostics, including power cycling, re-stabilisation and sensor rebasing. Users also benefit from free remote firmware upgrades for the life of the product and free of charge data processing algorithm upgrades for gas channels, which means customers can be reassured they are always the using the most up to date technology available, giving them the most accurate and reliable data possible.