Air quality: A global issue
All around the world, the issue of air quality is becoming increasingly relevant – especially in urban areas. More and more cities are installing measuring devices to record immissions – the accumulation of pollutants in the environment – and determine appropriate measures. The problem: individual, stationary measuring points do not offer a clear picture of the overall situation. This makes it difficult to take targeted measures. “It’s not enough to distribute a few devices around the city and then draw conclusions about the city as a whole,” explains Martin Schreivogel, Product Owner of the Immission Monitoring Box at Bosch Powertrain Solutions. “If there is a high concentration of nitrogen dioxide (NO2) at the Neckartor in Stuttgart due to heavy traffic, the situation may be completely different just two streets away.”
The Bosch solution: flexible and reliable
To address this problem, Bosch Powertrain Solutions has developed the Immission Monitoring Box (IMB) – a compact measuring unit only 60 centimeters tall and 40 centimeters wide. “These inexpensive measuring devices can be used flexibly and linked with each other,” says Schreivogel. As a result, users can cover larger areas with measurements and get a comprehensive picture of the air quality.
Flexibility wasn’t the only critical factor, though: the solution also needed to deliver accurate measurement results. “In Germany, the accuracy of fixed stations like the one located at Neckartor is strictly regulated down to the smallest detail,” says Schreivogel. “For smaller devices, however, there is no established standard.” In response, Bosch chose to evaluate the solution’s accuracy – and have it validated by an external measurement laboratory. “We offer a measuring device that allows the uncertainty range to be selected. This means that, for example, for measurements of NO2 concentration, the uncertainty cannot exceed 25 percent.” By comparison, for location-specific measurements, the uncertainty cannot exceed 15 percent.
Bosch IoT Suite as a core component
How does the solution work in practice? As Schreivogel explains: “The measuring device draws in air, which is then analyzed by various sensors. The corresponding values are determined on the basis of this data. In Europe, the focus is primarily on particulate matter and NO2. In Asia, issues like carbon monoxide (CO) and sulfur dioxide (SO2) are also important. The solution’s modular structure allows us to measure exactly the values that our customer needs.”
According to Schreivogel, the measurement process is a bit like looking for the proverbial needle in a haystack: in the case of NO2, for example, the Immission Monitoring Box has to detect a concentration that is roughly 1,000 times lower than the level for a typical exhaust gas sensor.
In addition, factors such as temperature or humidity can falsify the result. To prevent this, the hardware must be adapted to the environmental conditions. Additionally, software is used to adjust the data in order to obtain a meaningful measured value.
After pre-processing on the device, the data is sent to the cloud via the mobile network, where the services of Bosch IoT Suite are used. The Bosch IoT Insights data management service helps to administer the data and prepares the information in customizable dashboards. Users can thus quickly get an overview and draw insights from the data.
In addition, the interaction of Bosch IoT Device Management (Digital Twin) and Bosch IoT Rollouts (Update Management) ensures that software updates are carried out efficiently and conveniently over-the-air. “Not only can we roll out bug fixes; we can also optimize the devices’ software functions,” says Schreivogel. “For example, when it comes to compensating for environmental influences such as temperature or humidity in the measured values.”
The solution in action
Various cities around the world are already relying on the Bosch solution: the Immission Monitoring Box is currently being used in Germany, France, Croatia, India and Vietnam. London, too, is using it to take air quality measurements. “As a first step, we are creating transparency with our solution,” says Schreivogel. “Cities now have a better idea of where they need to take action to improve air quality – and can measure the success of these actions.”
What do such measures look like? One parameter is traffic. With the help of intelligent traffic control, for example, exhaust emissions can be reduced at busy intersections, improving air quality. “You always have to make sure you actually fix the problem instead of just moving it to another part of the city,” Schreivogel explains. Accordingly, cities need to continually test the effectiveness of measures and keep refining them. “London, for example, has implemented different traffic light circuits and then observed how the immission distribution developed in an entire neighborhood.”
But it’s not just cities that benefit from the solution. “One trend is measuring air quality near industrial facilities,” Schreivogel says. “There are some countries where the impact of industrial plants on the environment needs to be proven. So, it makes sense to build a network of our measurement devices around a given factory.”