Recognised Expertise

Alphasense has coupled more than 20 years of sensor science and engineering with our analysis knowledge to bring you a device that delivers air quality data.

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Sensors for Applications

Use our Electronic Diffusion Tube (EDT) with any of seven gas sensors: NO2, NO2+O3, NO, SO2, CO, H2S, NH3 to see the full air quality picture- wherever you are.

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Get the full picture

You can estimate air quality by monitoring PM 2.5 but to get the full picture you also need to measure polluting gases. The Alphasense EDT meets this need.

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Made by Alphasense

More than two decades of research, engineering manufacture and testing give us the edge. Proven sensors for ppb measurements joined with our knowledge translates into reliable air quality data. We work with others to write the standards that drive our industry and ensure data reliability. Visit our website

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Versatility across single and multiparameters

Simple indicative particle monitors or high priced multiparameter air quality networks? An air quality monitor that works alone, joins a network or can roam and map a city-the EDT can fill the gap.

Palmes-type diffusion tubes

Co-locate with Palmes-type diffusion tubes; the EDT records the diurnal and weekly patterns, supporting validated diffusion tube concentrations and providing peak readings along with the diffusion tube long term averaged concentrations.

Better spatial resolution

When budgets are tight but you need better spatial resolution, the EDT partners with multiparameter networks to provide high quality data at critical locations.

Map a city

When confronted with an air quality problem that needs a quick answer, using the EDT in Roaming mode lets you rapidly map a city, locating the hotspots that will require further investigation.

More to Come

Our scientists, mathematicians and coders are developing new data processing modules to analyse air quality data with new answers: gas transient correction, remote auto-calibration, PM and particle size profiling, pollen identification, and in the future VOC speciation at ppb concentrations.

Our AQ Gateway analysis modules can work with third party data and Alphasense-based air quality systems.

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Wide range of sensors

EDTs can be fitted with any one of these gas sensors, fitting your requirement. Use more than one EDT

  • NO2, NO and CO to support CO2 emission indexing
  • H2S and NH3 for nuisance odour plume detection
  • NO2, SO2 and O3 for urban air quality
  • CO, NO2+O3 and H2S for indoor air quality
  • NO2 and SO2: the critical pollutants near harbours

Wide Range of Uses

Whether mapping a city, hunting down pollutants, following diurnal patterns to support Palmes tubes or understanding your neighbourhood, the EDT provides traceable and affordable air quality data. There are many other applications:

Deploy with Drones

Weighing less than 140 grams, EDTs can be deployed with drones to sample ship and vehicle plumes in harbours, at tunnel entrances and lorry holding zones. Combining NO, NO2 and CO with CO2 define the emission index.

Validate Network Quality

Combining continuous fixed site air quality networks with EDTs in Roaming mode can optimise network accuracy by collocating EDTs first with a reference station then with network nodes to validate network data quality.

Indoor Air Quality

Indoor air quality depends on the outdoor air. EDTs measuring both the outdoor air and the indoor air in lobbies, offices and meeting rooms check if the BMS is providing adequate fresh air.

Monitor Nuisance Odour Plumes

Ring-fence H2S and ammonia EDTs around a VOC source to monitor nuisance odour plumes. Frequent downloads provide immediate feedback during servicing and maintenance operations and a ring of EDTs can map odour plumes to follow up on local complaints as wind direction changes.

Track Fugitive Industrial Plant Emissions

Distributed EDTs will track fugitive industrial plant emissions. Temporal and special information can triangulate the source, and the time can align with process changes for both leak detection and ensuring compliance.

Monitor Construction Sites

Measure NO2, CO and NO concentrations to monitor construction sites for emissions compliance, especially for peak concentrations. Ring fencing the site ensures you measure plumes, whatever the wind direction.

Bolster Research

Researchers need to collect data quickly, without designing new instrumentation. The data must be accurate, traceable and the analysis transparent. The EDT and AQ Gateway together meet this need.

Support Education

Rugged and easy to use, EDTs are an excellent low cost educational tool when teaching air quality. Students can explore their neighbourhood, monitor pollution during school runs and chase down nuisance odours.

Aid Community Air Quality Projects

With its user-friendly interface and rugged construction, the EDT is ideal for community air quality projects. Citizens can map out dangerous polluting gases in their neighbourhood, monitor diurnal pollution patterns at critical junctions or ensure that at-risk people are not in danger from NO2 or ozone.

Using AQGateway

Compensated gas concentrations

The AQ gateway turns EDT raw data into corrected and compensated gas concentrations, reported as either ppb or µg/m3. Data is uploaded from a mobile device App and batch processed and results can be downloaded as a .csv file to a PC or reviewed as a time series. Data is analysed using different algorithms, allowing you to choose the best analysis tool for your scenario. The original raw data is always stored for traceability and both temperature and relative humidity are recorded and reported.

Parallel data analysis

Air quality network providers build, deploy and maintain their own multiparameter monitoring networks, measuring gases and particles plus environmental parameters. Most network providers process their own data using proprietary algorithms. The AQ Gateway provides added value by cloud-to-cloud processing, offering the network provider parallel data analysis opportunities: important where algorithms have been developed in one climate but the networks are being deployed globally in more challenging climates. Our AQ Gateway analysis modules can be designed for third party as well as Alphasense-based air quality systems.

Additional information layer

As luminaires become multipurpose monitoring platforms, manufacturers are being asked to add air quality to CCTV, meteorological and traffic control monitoring features. Adding EDTs or EDT cores with other measurements such as the Alphasense OPC for particles gives another information layer. Processing EDT data through the AQ Gateway requires data format compatibility: Alphasense can partner to provide the needed API for smooth data transfer. Our knowledge and experience in air quality data analysis ensures your air quality data is validated and traceable.