Public health initiatives around air pollution have closely tracked the availability of technologies for monitoring. Instrumentation firm ACOEM UK is supporting emerging initiatives in relation to wood-burning stoves and the emergence of indoor air quality as a serious priority of occupational health. And the company is also beefing up its UK-based capabilities to support industry professionals in these areas with fast turnarounds on equipment calibration and servicing, as Envirotec discovered in conversation with the group’s managing director Derrick Jepson.
For the UK of today, two issues currently focusing the attention of public health are the use of wood-burning stoves, and indoor air quality (IAQ), topics that seem to be finally coming to the fore.
Wood burning: Quantifying the hazards
While it can be a less expensive option for home heating, wood burning is “the most polluting way to heat your home” as one upcoming campaign notes.1 It produces PM2.5, including respirable particles of brown and black carbon. Clean Air Night, taking place in London on Thursday 22 January 2026, hopes to raise awareness of the issue, and ACOEM UK will be involved in air monitoring surrounding the event, to build the case for tighter controls on the burning of wood.
What happens when this kind of pollution gets indoors? This is now a focus of attention, said Derrick, and interest in IAQ is growing alongside other developments too: energy prices have certainly heightened vigilance around keeping windows closed, and expedited the move to hermetically sealed environments, with office workers more often breathing stale air as a result. Better ventilation is helping, but systems such as air conditioning don’t always work optimally, a fact that is presenting its own requirements for improved monitoring of IAQ, to inform HVAC maintenance.
At a recent event in November ACOEM UK demonstrated its handheld monitors, and showed that – by standing underneath the aircon system indoors and measuring particulates – you could determine whether a bus stopping outside was diesel, electric or hybrid. “If there was no increase in the background of particulates, we could confidently conclude it was an electric bus,” explained Derrick. “If the increase was slight then it was hybrid, and if it spiked as it pulled away, it was clearly diesel.”
Clearing the air
A range of handheld instruments developed with IAQ in mind were developed by Met One, as many familiar with this sector will be aware, which ACOEM UK acquired six years ago (“Met One Powered by ACOEM” is the designation now used). A device like the group’s Aerocet 532 Handheld Particle Monitor, says Derrick, answers the call for something that lets you quickly and easily check the cleanliness and efficiency of the air conditioning system. “You have to be able to press a button and get a number,” he suggests, “or in other words, to get accurate readings each time you call upon it.” He offers a brisk summary of the overall ethos: “You can only manage what you measure.”
The device lets you measure the quantities of different particle size fractions (PM1, PM2.5, PM4, PM7, PM10) as well as total suspended particulate (TSP) levels.
It can be used for zone monitoring, where measurements are taken around the interior of a building, near the ceiling registers of aircon systems, for example. A consultant or service engineer will want to assess whether the filtration systems are doing their job. A handheld particle counter will not tell you the velocity of the air in the HVAC system, but it will give the user an accurate measurement of filter efficiency and concentrations of particulates inside the building.
“And you still get issues if it isn’t serviced regularly, or if the filters are not changed,” he says. “If a lot of dust is drawn into the building then you get a very efficient dusting mechanism.” The extreme end of such problems seem visible in the phenomena of “sick building syndrome”, which studies have linked with high levels of ultrafine particulate pollution, and this kind of material being sucked into a building by the HVAC system, with occupants complaining of headaches and other problems.
New quick calibration service
The reputation of the Met One instruments has been built in part on being rugged and robust, he says, and for air-quality consultants, for whom such instruments are their “bread and butter”, keeping them in good working order – and minimising downtime – is a priority. Towards that end, ACOEM UK is going live (at the time of writing) with a new calibration and servicing capability, which will include support for the Met One product range and will provide a quick turnaround (two weeks is the aim). This seemingly redoubled ethos of “support what we sell” will cover things like NIST calibration of instruments that measure “a broad spectrum of airborne pollutants”.
With particle count measurement devices, for example, they run tests using “calibrated dust”, where a test aerosol with a known particle size distribution is measured with a reference instrument, then with one of the Met One handheld monitors, and the compared results are used to finely calibrate the latter. This is a practice already conducted with the MCERTS-grade reference instruments supplied by the firm, but which is now being applied to handheld particle monitors.
The servicing and calibration will be conducted at a site in Tewkesbury, one of three UK premises of the group (the others being in Glasgow and Banbury). This will be a service centre covering the UK, Ireland and the Nordic countries.
The calibration process for Met One handheld instruments is proprietary and only ACOEM UK is authorised to issue manufacturer backed calibration certificates for Met One handheld instruments.
