From vision to action

The city of Ghent set a good example by being the first to start measurement experiments. The city of Bruges followed suit. Choosing the right sensors was crucial in this regard. During the sensor selection process, numerous factors were taken into account: ease of maintenance, robustness in urban environments, data openness, simple installation, flexibility in calibration, and user-friendly dashboards. The careful preparation laid the foundation for a successfull implementation.

Electrochemical sensors: what are they?

In the LIFE CityTRAQ project, we use electrochemical and particulate matter sensors to measure gas pollutants (nitrogen dioxide and ozone). These sensors generate electricity based on a chemical reaction inside the sensor module. This electricity is proportional to the concentration of the gas being measured in the outside air. The device then calculates the concentration of gas that generated the current. This is called calibration.

Because this process is influenced by factors such as temperature and humidity, regular adjustments, for example at the change of seasons, is essential to ensure reliable measurements.

Testing, testing and more testing

Before the sensors are effectively deployed during a measurement campaign, they undergo a co-location test. During this test, they are temporarily placed at an official VMM reference measurement location. This allows us to evaluate the performance of the sensors and correct any deviations. Parameters such as ‘between sensor uncertainty’ (the degree to which two different sensor signals differ) and the ‘R-squared value’ (the difference in behavior between the sensor and the reference monitor) provide insight into the reliability of the measurements.

Collaboration as the key to succes

Dankzij de sensoren van het LIFE CityTRAQ-project kunnen we luchtkwaliteit in de pilootsteden op een toegankelijke manier opvolgen. Door grondige testen en continue kalibratie zorgen we ervoor dat de metingen zo betrouwbaar mogelijk zijn.

The success of a measurement campaign is not only due to technology, but also to cooperation with local authorities. Schools and citizens were involved in the pilot projects. This provides valuable feedback and greater support and awareness of air quality.

Getting started

Local authorities interested in setting up their own air quality projects can consider the following steps:

Preparation and planning: set clear goals and determine which air quality aspects need to be measured.

Sensor selection: use the lessons learned and requirements to choose the right sensors.

Pilot project: start with a small-scale pilot project to test and evaluate the selected sensors.

Implementation: after successful testing, scale up the project and implement the sensors in the desired areas.

In this way, we can work together to build a healthier living environment for everyone.

Disclaimer: these are the requirements and experiences within a Flemish context and the pilot projects launched within the LIFE CityTRAQ project.