/

/

/

City air, measured street by street.

A few reference stations tell a city whether it meets the law; they cannot say which street or school is worst. Dense sensors calibrated against the reference stations, with weather to trace sources, report to one record the environment department, health teams and residents can trust.

Industry

Cities

Measurements

5

Sources cited

5

1. Cities · Urban air quality

   The street the station cannot see

   A city may have a handful of reference stations and thousands of streets. The station tells the city whether it meets the law; parents want to know about the street outside their school. Dense sensors calibrated against the stations answer both, if their numbers can be trusted.

2. What is measured

   Particles, gases and the wind

   Reference stations measure particles and gases to the legal methods. Sensor nodes on lamp posts and walls measure particles and nitrogen dioxide at breathing height between them, and weather stations measure the wind that carries pollution from its sources. Every reading names its point and height.

   Instruments

   Reference stations · Sensor nodes · Rooftop and street weather

3. The base node

   Calibration at the district node

   Each district node applies the calibration learned at the reference station to every sensor, flags drift and faults, and computes hourly means and episode alerts before anything is published. Every value carries its calibration and quality flag. A sensor that drifts is flagged, not hidden.

4. Radio and links

   Cellular, LoRaWAN and the city’s fibre

   Reference stations and sensor nodes on street furniture report over the public cellular network. Dense battery sensors on lamp posts reach gateways on roofs over LoRaWAN, and reference stations in city buildings use the city’s fibre where it runs. Every path buffers its data.

   Links

   Public cellular · LoRaWAN · Fibre

5. How it works

   From a lamp post to a school alert

   A sensor outside a school reads particles rising on a still winter morning. The district node calibrates it against the reference station, sees an episode and sends an alert to the school and the health team. The map updates, and the record keeps the reading and the calibration.

6. From order to operation · Order

   Scope the air plan and the questions

   The scope reads the air quality plan, the reference network, the places the city worries about and the questions sensors must answer. Nexus Observatory Inc. returns the point plan around each reference station, the calibration design, the integration with the city’s data platform and a price per point and per service.

   Plan a deployment

7. From order to operation · Survey

   Walk the streets with the questions

   Crews walk candidate streets, schools and junctions with the environment team, choosing lamp posts and walls at breathing height and away from vents and flues. They check gateway coverage from roofs and power on street furniture, and plan co-location at reference stations.

8. From order to operation · Permits

   Street furniture and data

   Sensors on lamp posts and walls need the owner’s consent and follow the city’s street works rules. Publication of street-level data is agreed with the environment and health teams. Every consent is kept with the point it covers. Residents near each point can ask what it measures and see its data.

9. From order to operation · Build

   Build and co-locate first

   Sensor nodes, gateways and reference station links are built, tested and enrolled with their identities. Every sensor first runs beside a reference station so its calibration is learned before it goes to its street, as the performance standard describes. Sensors that fail co-location are not deployed.

   Open the Station Builder

10. From order to operation · Install

    Install at breathing height

    Crews mount sensor nodes at breathing height on lamp posts and walls, weather stations on roofs and gateways where they see the district. Every point is photographed and located, with its distance from the kerb recorded for the record. Each point is checked for nearby sources such as flues.

11. From order to operation · Commission

    Check against the reference

    Each node proves its identity. Calibrated readings are compared with the nearest reference station, outliers are investigated, and episode alerts are tested to the environment team. A point joins the published map only when its checks pass. Results are kept with each sensor’s record for later audits.

12. From order to operation · Operate

    Act street by street

    The environment team sees street-level air beside the reference stations, with wind to trace sources. Episodes trigger the city’s measures, schools and health teams receive alerts, and the air plan is judged on evidence. Residents see the same map. The record shows which measures worked.

13. From order to operation · Maintain

    Recalibrate, rotate, replace

    Sensors are rotated back to reference stations on schedule to check drift, cleaned and replaced at end of life. Reference stations follow their own quality programme. Every change is recorded, so street-level series stay trustworthy. Spares are kept calibrated, so a failed sensor is swapped quickly and gaps stay short.

    Book field services

14. Data products

    For planners, schools and residents

    Environment teams and residents receive street-level maps; schools, health teams and the public receive episode alerts; air quality planners receive source attribution with wind; city leadership and regulators receive reporting indicators. Each product carries its calibration and quality flags. All products are dated and versioned.

    See the data products

15. Evidence

    Numbers a regulator accepts

    Every reading, calibration, alert and change is signed and kept. Sensors are evaluated to the European performance standard against reference stations, limits follow the ambient air rules, health comparisons follow WHO guidelines, and indicators follow the city indicators standard. Calibrations are open to review.

    Drawn against

    Directive (EU) 2024/2881 · CEN/TS 17660-1 · WHO air quality guidelines · ISO 37120

16. What you get

    Hybrid air-quality networks

    Reference analysers plus calibrated low-cost nodes, with co-location calibration and an open-data interface. Delivered as managed service and data licence, for cities, environment agencies, industrial sites. Scale: City-wide to national. Service levels are written as numbers you can measure on your own dashboard.

    Talk to sales

17. Next step

    Plan urban air quality with us

    Tell us the site, the measurements and the rules it answers to. We reply with a survey proposal, a design and a scope for urban air quality. An engineer replies with a survey proposal and a scope, and the plan grows from one site to the network you need, at your pace.

    Plan a deploymentOpen the Station BuilderOpen the Studio

01The place and its hazards

Where it runs, and what can go wrong.

Operating contextCities assess air quality against legal limits with reference stations, and increasingly with sensor networks that show variation between streets, schools and junctions. Health guidelines are stricter than many limits. Low-cost sensors need calibration and quality control before their numbers can be used, and air plans need sources traced.

Hazards

• Exposure at schools, hospitals and busy streets
• Limit breaches found too late to act
• Sensor numbers trusted without calibration
• Episodes from traffic, heating, industry or smoke
• Unequal exposure between neighbourhoods

02What must be measured

What, where, how often, and under which rules.

Each measurement names where it is taken, how often, and the public standard or regulation behind it. Numbers in the sources column open the cited source below.

03The observation stack

From one base unit to a network.

The same blocks at every scale: instruments and a base node, a site with its radio, a fleet run as one, and a network federated on the open protocol.

1. 01

   Base unit

   A street point: a particle and gas sensor node, or a reference station read by a small node that signs every value.

   Build a station →
2. 02

   Site

   A district: sensor points around a reference station, a gateway on a roof and cellular to the city.

   Plan a site →
3. 03

   Fleet

   Every point of a city run as one fleet, with one calibration process and one record.

   Managed offers →
4. 04

   Network

   Cities, regions, health agencies and researchers exchange air data through open standards.

   The open protocol →

• 01Air quality monitor
• 02Compact weather station
• 03LoRaWAN gateway
• 04Micro node (Nano)
• 05Cellular modem/router
• 06Solar array
• 07Pole

Radio and links

Public cellular

Reference stations and sensor nodes on street furniture report over the public network the city already pays for.

Radio and links

LoRaWAN

Dense battery sensors on lamp posts reach gateways on roofs at very low power.

Radio and links

Fibre

Reference stations in city buildings use the city’s own fibre where it runs.

Edge computeEach district node applies the calibration learned at the reference station to every sensor, flags drift and faults, and computes hourly means and episode alerts before publishing.

PowerSensor nodes run on street-light power or small solar panels; reference stations run on mains in their enclosures.

04How it works

From the instrument to the product.

One observation’s path, tier by tier, with the interface on every link and a bill of materials below; then how the one node grows to a site, a fleet and federated networks.

05From order to operation

Every step, from the first call to a running site.

The same crew and the same record carry the work from scope to maintenance.

1. 01 Order

   Scope the air plan and the questions

   The scope reads the air quality plan, the reference network, the places the city worries about and the questions sensors must answer. Nexus Observatory Inc. returns the point plan around each reference station, the calibration design, the integration with the city’s data platform and a price per point and per service. 1

2. 02 Survey

   Walk the streets with the questions

   Crews walk candidate streets, schools and junctions with the environment team, choosing lamp posts and walls at breathing height and away from vents and flues. They check gateway coverage from roofs and power on street furniture, and plan co-location at reference stations.

3. 03 Permits

   Street furniture and data

   Sensors on lamp posts and walls need the owner’s consent and follow the city’s street works rules. Publication of street-level data is agreed with the environment and health teams. Every consent is kept with the point it covers. Residents near each point can ask what it measures and see its data.

4. 04 Build

   Build and co-locate first

   Sensor nodes, gateways and reference station links are built, tested and enrolled with their identities. Every sensor first runs beside a reference station so its calibration is learned before it goes to its street, as the performance standard describes. Sensors that fail co-location are not deployed. 3

5. 05 Install

   Install at breathing height

   Crews mount sensor nodes at breathing height on lamp posts and walls, weather stations on roofs and gateways where they see the district. Every point is photographed and located, with its distance from the kerb recorded for the record. Each point is checked for nearby sources such as flues.

6. 06 Commission

   Check against the reference

   Each node proves its identity. Calibrated readings are compared with the nearest reference station, outliers are investigated, and episode alerts are tested to the environment team. A point joins the published map only when its checks pass. Results are kept with each sensor’s record for later audits.

7. 07 Operate

   Act street by street

   The environment team sees street-level air beside the reference stations, with wind to trace sources. Episodes trigger the city’s measures, schools and health teams receive alerts, and the air plan is judged on evidence. Residents see the same map. The record shows which measures worked. 2

8. 08 Maintain

   Recalibrate, rotate, replace

   Sensors are rotated back to reference stations on schedule to check drift, cleaned and replaced at end of life. Reference stations follow their own quality programme. Every change is recorded, so street-level series stay trustworthy. Spares are kept calibrated, so a failed sensor is swapped quickly and gaps stay short.

06Data products and integration

What it delivers, to whom, and into which systems.

Data products

• Street-level air quality mapsEnvironment teams and residents
• Episode alertsSchools, health teams and the public
• Source attribution with windAir quality planners
• Reporting indicatorsCity leadership and regulators

Integration

• City data platformObservations are served through OGC SensorThings with calibration and quality flags.
• Regional reference networkSensors are calibrated against reference stations and never replace them in legal assessment.
• Public informationMaps and alerts are published on the city’s channels and open data portal.

Exchanged through OGC SensorThings API, CEN/TS 17660, WHO air quality guidelines.

07Questions buyers ask

Before you scope it.

Can sensors replace reference stations?

No. Reference stations remain the legal basis; sensors show variation between them.

How accurate are the sensors?

As accurate as their calibration shows. Each is co-located with a reference station and checked on schedule.

Who sees the data?

The city decides; street-level maps are usually published openly.

Can schools get alerts?

Yes. Episode alerts go to schools and health teams the city names.

08Resources

The sources behind this page.

Public standards, regulations and guidance, cited where they apply. Each applies only where its jurisdiction or scope does.

1. 1Directive (EU) 2024/2881 on ambient air quality and cleaner air for EuropeEuropean Union · 2024
2. 2WHO global air quality guidelinesWorld Health Organization · 2021
3. 3CEN/TS 17660-1: Air quality, performance evaluation of air quality sensor systems, gaseous pollutantsEuropean Committee for Standardization · 2021
4. 4Guide to Instruments and Methods of Observation (WMO-No. 8)World Meteorological Organization
5. 5ISO 37120: Sustainable cities and communities, indicators for city services and quality of lifeInternational Organization for Standardization

09Related

Use cases and solutions.

10Cities: specialized fields

Other fields of this industry.

Bring us the site.

Plan a deployment, configure a station, model it in the Studio or talk to sales. The form names who receives your details.