TL;DR — The US EPA’s Enhanced Air Sensor Guidebook outlines recommendations when it comes to choosing the right air quality monitoring equipment for your project. By taking into account the specific features of different low-cost sensor technology — such as the device’s accuracy and reliability, the pollutants it can monitor, its ease of use and maintenance requirements, and its data analysis capabilities — you can choose the air quality monitoring equipment that will be most effective for your project goals.
The US EPA Enhanced Air Sensor Guidebook
This blog is part of a series that highlights key themes from the US EPA Enhanced Air Sensor Guidebook, whose updated version was published in 2022. The guidebook covers a variety of topics involving low-cost air quality sensor use.
Today, we’ll be breaking down the Guidebook’s recommendations when it comes to selecting the right air quality monitoring equipment for your project.
A variety of air quality monitoring equipment exists with various types of low-cost sensors now available.
However, these technologies vary in their different specifications — such as accuracy and durability — making it important to carefully select the appropriate air quality monitoring equipment for your project and its goals.
Key things to look for in air quality monitoring equipment
Accuracy and reliability
Both accuracy and reliability are important parameters to consider when it comes to determining the data quality of different low-cost sensor technologies.
Accuracy describes how well the sensor’s measurements of any given pollutant match the measurements from a reference-grade monitor. In contrast, reliability refers to how consistent the sensor’s measurement points are to each other, rather than to that of the reference device.
The accuracy of a sensor is determined by precision and bias. Precision is how well the sensor reproduces the measurement as compared to the reference monitor under the same environmental conditions. Bias describes the amount of measurement error in the measurements — that is, whether they are higher or lower than the true concentration, and to what degree.
To learn more about measurement error, check out our blog covering mean absolute error (MAE) here.
You can learn more about evaluating sensor accuracy and reliability by checking out our blog series here.
It is important to look for a sensor that has documented accuracy and reliability under similar environmental conditions to those it will be operating in, ensuring it will collect high-quality data during the operation of the monitoring project.
Range of pollutants monitored
It is essential to choose air quality monitoring equipment that will measure all potential pollutants of interest at the ranges that the network will likely detect over the course of the monitoring project.
The Clarity Node-S measures particulate matter (PM) and nitrogen dioxide (NO2), with add-on modules available for other air quality measurements, like wind and ozone.
Additionally, it is important that the sensor technology can detect both high and low concentrations, as the pollutant concentrations that the sensor may come across during monitoring can vary widely.
Ease of use and maintenance
Ease of use is important to consider because different individuals with a wide array of experience and technical knowledge may need to operate a sensor.
If a skilled technician or other expert is needed, this can also factor into the operating costs of the network.
Maintenance involves how often repair or replacement is needed, what calibration services must be kept up, and how durable the sensor is, among other factors.
Consider the requirements of your specific sensor technology and the costs associated with it.
Data reporting and analysis
Choosing the right technology does not end with the hardware specifications — it’s equally important to choose an air quality monitoring solution that meets your project’s needs for data processing. Consider both the technology’s calibration process — to ensure that accurate data is collected — as well as the platforms where data will be presented and visualized.
For more information, read our blog covering calibration and its importance here.
Data handling and access are also important. You should consider:
- How data is stored
- What format the data is stored in
- How data is visualized and distributed
- Who can access the data and who has ownership rights to it
- The length of time that the data will be available for
At Clarity, our Clarity Cloud houses the Node-S air quality measurements, which are uploaded via a cellular connection.
Data can be accessed via the Clarity Dashboard which allows for data to be managed and visualized, with both raw and calibrated data easily accessible. By having a platform that allows for easy data access and management, you can reduce the time you spend on processing data and focus on making an impact with your air quality monitoring data.
Cost and value
The cost of different air quality monitoring sensors can vary widely.
It is important to consider both upfront or purchase costs as well as what the operational costs of the sensors will be over the long term.
By minimizing the operational costs associated with maintaining an air quality monitoring network, Clarity’s Sensing-as-a-Service model makes it possible for anyone to collect reliable, high-density air quality data at a fraction of traditional costs. This makes it economically feasible to scale air quality monitoring networks to dozens, hundreds, or even thousands of measurement points.
Consider what data quality and specifications — such as data transmission and storage, calibration services, et cetera — are needed for your specific air quality monitoring project.
Logistically, it is important to choose equipment that matches what can be provided in the environment. This may involve power needs and connectivity requirements, which vary widely depending on where the sensors will be sited.
Read our blog on siting and installing low-cost sensors to learn more about the requirements that different sensors may have.
Durability is also an important factor to consider, as different environments will put different amounts of wear and tear on the sensor. Consider what conditions the sensors in your monitoring project will need to withstand over the course of their use.
Air quality monitoring equipment in action
Different types of monitoring projects, businesses, and organizations will benefit from thoroughly evaluating the right type of air quality monitoring equipment for them.
The Denver Department of Public Health and Environment (DDPHE) wanted to be able to quickly and flexibly respond to potential air pollution hotspots in their city.
They rapidly deployed Clarity Node-S devices during protests on social injustice in order to assess the possible impacts of air pollution on public health during this event.
The flexibility and ease of deployment of low-cost sensors allowed for their rapid deployment, and their low cost meant that more sensors could be used in order to collect more hyperlocal, high-resolution data.
Read more about our work with Denver here.
Groundwork Richmond had the goal of establishing an air quality monitoring network that could collect more real-time, local air quality data in order to support the longstanding concerns of residents. The city has long experienced high levels of air pollution due to a refinery and freeways running through the community, and residents have suffered the consequences on their health.
Officials at Groundwork Richmond wanted monitors that did not need a dedicated electricity supply so that they could be more flexible in where they were sited. This meant that monitors could be deployed in the locations that were most important to community members.
They also wanted sensors that would not go offline in case of power outages, making Clarity Node-S devices a great pick for them.
Read more about our work with Groundwork Richmond here.
Setting your project up for success
It is highly important to thoroughly evaluate potential air quality monitoring equipment to make sure that it will be suitable for your specific project goals and needs. In doing so, you will ensure the best bet for success for your air quality monitoring network.
Interested in measuring air quality for cleaner air, improved physical and mental health, and a healthier climate? Get in touch with our team to learn more about our Sensing-as-a-Service solution for governments, businesses, and community organizations, using our Clarity Node-S monitors and modules that do not depend on infrastructure like WiFi or power — making them especially resilient during environmental disasters.