Index Air Quality Monitoring for Light and Active Mobility

Abstract

Light and active mobility, as well as multimodal mobility, could significantly contribute to decarbonization. Air quality is a key parameter to monitor the environment in terms of health and leisure benefits. In a possible scenario, wearables and recharge stations could supply information about a distributed monitoring system of air quality. The availability of low-power, smart, low-cost, compact embedded systems, such as Arduino Nicla Sense ME, based on BME688 by Bosch, Reutlingen, Germany, and powered by suitable software tools, can provide the hardware to be easily integrated into wearables as well as in solar-powered EVSE (Electric Vehicle Supply Equipment) for scooters and e-bikes. In this way, each e-vehicle, bike, or EVSE can contribute to a distributed monitoring network providing real-time information about micro-climate and pollution. This work experimentally investigates the capability of the BME688 environmental sensor to provide useful and detailed information about air quality. Initial experimental results from measurements in non-controlled and controlled environments show that BME688 is suited to detect the human-perceived air quality. CO₂ readout can also be significant for other gas (e.g., CO), while IAQ (Index for Air Quality, from 0 to 500) is heavily affected by relative humidity, and its significance below 250 is quite low for an outdoor uncontrolled environment.

Keywords: MOx sensors; air quality index; light mobility.

Figure 1

BME688 default heating profile, adapted from [35].

Figure 2

Diagram representing the firmware configuration scheme of BME688 through Arduino IDE.

Figure 3

The ACS DY110 test chamber adopted for the characterization of the BME866 sensor (a) and the Nicla Sense ME placed inside the active volume of the chamber (b).

Figure 4

Demonstrator information flow. The devices and the integrated components are highlighted.

Figure 5

Fluxing chamber setup. Custom stainless-steel chamber (1 L volume) located inside M120-TBR climatic chamber (a) and details of the connection of the Nicla Sense ME to metallic transistor outline (b).

Figure 6

Acquired measurements (T, RH, P, RES, CO_2eq, and IAQ) of the experiments in the office space for the Nicla₁ (in blue) and Nicla₂ (in red).

Figure 7

Measures (T, RH, P, RES, and CO_2eq, IAQ) acquired in the climatic chamber for Nicla₃.

Figure 8

Behavior of RH, IAQ, CO_2eq, and RES of Nicla₁ (in blue) and Nicla₂ (in red) at a temperature of 20 °C in the fluxing chamber.

Figure 9

Behavior of gas resistance, CO_2eq, and IAQ of Nicla₁ at T = 20 °C and RH = 20% in the fluxing chamber with an injection of CO₂ with 600 ppm concentration.

Figure 10

Behavior of gas resistance, CO_2eq, and IAQ of Nicla₁ at T = 20 °C and RH = 20% in the fluxing chamber with an injection of CO with 20 ppm concentration.