What are we talking about when we say sensing device?

Description

A sensing device, often referred to simply as a sensor, low-cost sensor, sensor node, etc., is a technological tool designed to detect and measure physical properties or environmental conditions. Sensors come in various types (e.g. static or mobile) and can be used to monitor a wide range of parameters such as temperature, pressure, humidity, light intensity, motion, sound, chemical composition, and more. In Citizen Science initiatives, a wide range of sensing devices can be employed to engage volunteers in environmental monitoring and data collection efforts. These devices are typically selected based on their ease of use, affordability, and suitability for non-experts.

Why is this relevant?

Identifying the type of sensing devices needed is paramount for effective monitoring due to various factors. Firstly, it ensures the accuracy and precision of measurements by matching the devices’ capabilities with the requirements of the application. Secondly, selecting a device suitable for the monitoring environment guarantees optimal performance under specific conditions such as temperature, humidity, and exposure to contaminants. Additionally, considering factors like measurement range, resolution, response time, and cost ensures that the chosen equipment meets the monitoring objectives efficiently. Moreover, compatibility with existing hardware or software platforms, as well as adherence to application-specific requirements and standards, are critical for seamless integration and regulatory compliance. Overall, choosing the right type of Sensing Device ensures reliable data collection, analysis, and interpretation, ultimately supporting informed decision-making in various fields of monitoring.

How can this be done?

Some common types of sensing devices used in Citizen Science and Citizen Observatories include:

1. Air quality sensors: also referred as air quality low-cost sensors, can measure pollutants such as particulate matter (PM), nitrogen dioxide (NO2), ozone (O3), sulphur dioxide (SO2), and carbon monoxide (CO) in the ambient air. These sensors are often used to assess air pollution levels in communities and identify sources of pollution.

2. Noise sensors: noise sensors can measure ambient noise levels in decibels (dB) and identify levels of noise pollution in urban and rural environments. These sensors are useful for assessing the impact of noise on human health and wildlife.

3. Water quality sensors: handheld or deployable water quality sensors can measure parameters such as pH, dissolved oxygen (DO), conductivity, turbidity, and temperature in bodies of water. Citizen scientists can use these sensors to monitor the health of rivers, lakes, streams, and coastal areas.

4. Weather sensors: weather sensors can measure atmospheric conditions such as temperature, humidity, barometric pressure, wind speed, and wind direction. These sensors are valuable for monitoring local weather patterns and understanding the impacts of climate change on ecosystems.

5. Soil sensors: soil sensors can measure parameters such as moisture content, pH, temperature, and nutrient levels in the soil. Citizen scientists can use these sensors to assess soil health, track changes in agricultural productivity, and monitor the impacts of land use practices.

6. Light pollution sensors: light pollution sensors can measure sky brightness and identify sources of artificial light pollution in urban and suburban areas. These sensors help raise awareness about the impacts of light pollution on astronomy, wildlife, and human health.

Some features of the sensing devices commonly used for engaging people in environmental monitoring are:

1. Real-time monitoring: sensing devices typically offer real-time data collection capabilities, allowing users to access and analyse data immediately for timely decision-making.

2. Portability: sensing devices that are intended to be easily transportable are designed to be lightweight and compact, facilitating monitoring activities across diverse locations and environments. For air quality monitoring for example, there are specifically-designed mobile sensors that can be mounted on cars and bikes, and wearable sensors that can be carried by people while going about their daily activities.

3. Compact size: sensing devices are typically compact and easy to handle, enhancing their usability and enabling deployment in various monitoring scenarios.

4. Battery-powered: many sensing devices operate on battery power, providing flexibility for deployment in remote or off-grid areas without access to external power sources. Some sensing devices are designed to be installed at home and are not battery powered.

5. Wireless connectivity: with options for Bluetooth, Wi-Fi, or cellular connectivity, sensing devices enable seamless data transmission to mobile devices or cloud-based platforms, facilitating real-time data sharing and analysis.

6. Low maintenance requirements: devices should ideally require minimal maintenance, reducing the need for specialized technical expertise and ensuring accessibility for non-experts over extended monitoring periods.

7. User-friendly interfaces: ensure that the use of the device is intuitive for the user, with minimal guidance needed to understand their operation. Sensing devices can usually be connected to an online data platform that provides simplified data visualization that aid the easy interpretation of the data. Data can often be accessed through dedicated mobile apps or mobile web-based dashboards, and devices can come with either built-in or external monitors or screens to easily see current readings

8. Affordability: a defining characteristic of sensing devices in COs is their affordability, making them accessible to individuals, communities, and organizations with limited financial resources, thereby democratizing access to monitoring technology and fostering grassroots participation in environmental monitoring efforts. However, one needs to be aware that the cost of the sensing device is only one part of the total cost of the monitoring, and other costs and fees related to communication, maintenance, electricity, data storage, etc also need to be taken into account.

Useful resources

• Measuring air pollution with low-cost sensors. This brochure explains our current understanding of the advantages and disadvantages of sensors.
• Can commercial low-cost sensor platforms contribute to air quality monitoring and exposure estimates?. A research paper discussing how data quality can hinder the use of low-cost sensors for air quality monitoring.
• Applications of low-cost sensing technologies for air quality monitoring and exposure assessment: How far have they gone?. A research paper providing an extensive review of sensing devices for air quality monitoring, with focus on health exposure.

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