|Above: The Aeroqual AQY 1 installed at my home in Michigan. Note that this is not an ideal siting--an air quality monitor should be set up in an area free of potential air flow influences of buildings and vegetation.|
Advances in technology have led to the development of relatively cheap air pollution sensors suitable for personal use, and wunderground is actively working to build up a network of these low-cost air pollution instruments (like we did for personal weather stations, with our network now over 300,000-strong!) Personal air pollution sensors (PAPS) typically cost a few hundred dollars, but often have measurement capabilities competitive with commercial sensors used by the EPA, which typically cost $5,000 - $20,000. WU is working with companies that make personal air pollution sensors to make them compatible with the WU network. Later this year, we plan to integrate data from these devices into WU products.
Of the six air pollutants deemed dangerous enough to human health that the EPA issues official standards for them, by far the most dangerous pollutant is PM2.5—fine-sized particles less than 2.5 micrometers in diameter. These fine particles are blamed for about 88% of the approximately 100,000 premature yearly deaths due to outdoor air pollution in the U.S., and about 85% of the estimated 3 million global outdoor air pollution deaths each year. In July, I reviewed the excellent PA-II PM2.5 sensor, available from purpleair.com for $250. Today, I offer details on another PM2.5 sensor that I’ve been testing—the Aeroqual AQY 1, which has the additional capability of measuring two other key pollutants: ozone and nitrogen dioxide (NO2). According to the Health Effects Institute, ozone is the pollutant responsible for the other 12% of air pollution deaths in the U.S.--killing approximately 12,000 people per year. Ozone is also responsible for about 400,000 - 700,000 air pollution deaths globally, so it is good to have an instrument that can measure both ozone and PM2.5.
|Figure 1. Example of the Aeroqual AQY 1 display for February 5 – 9, 2018, at my home monitor in Michigan.|
The Aeroqual AQY 1: for those seriously interested in air pollution measurement
The Aeroqual AQY 1 is the best instrument I’ve seen for non-professionals seeking a serious air pollution measurement capability, since the device measures three different pollutants: PM2.5, ozone, and nitrogen dioxide (as well as temperature and dewpoint). The AQY 1 was developed by Aeroqual, Inc., as part of a multi-year development project supported by the New Zealand Government. The AQY 1 is more expensive than a device that just measures PM2.5, costing over $1,000 (contact firstname.lastname@example.org for exact pricing).
The ozone instrument on the AQY 1 was evaluated by the South Coast Air Quality Management District (SCAQMD), the air pollution control agency for all of California’s Orange County and the urban portions of Los Angeles, Riverside and San Bernardino counties. They have an Air Quality Sensor Performance Evaluation Center that compares low-cost air monitoring sensors alongside one or more of the high-grade operational air monitoring sensors used by EPA.
According to SCAQMD’s intercomparison tests of nine low-cost ozone sensors made by different companies, the AQY 1 had the highest correlation with measurements made in side-by-side tests in the field and laboratory with the expensive commercial-grade sensors used by EPA. Thus, when a change in ozone levels occurred, the AQY 1 did the best job of tracking the change. The AQY 1 tended to degrade in accuracy over a period of months in field tests, though SCAQMD said that the three AQY 1 units tested performed “very well”, and had minimal down time. It is important to note that on their website, the following disclaimer is posted: “The field evaluations reports included on this website contain data collected at our monitoring station during a specific 30- to 60-day period and may not be duplicated at the same or different location, season, time period, or weather conditions (e.g. temperature, relative humidity, pressure, wind speed/direction). As the overall sensor performance may be affected by the specific environmental conditions experienced at our location during the time of testing, replication and/or duplication may not possible to achieve.” The SCAQMD has not yet tested the PM2.5 and nitrogen dioxide sensors on the AQY 1. Over 100 AQY 1 units have been deployed in Southern California as part of a research project with the SCAQMD.
I installed an AQY 1 sensor at my home in December, and have been impressed with its performance. The unit was easy to install; I plugged it in, ran a wire out my window, and nailed the sensor to the side of my house. There is currently not a wireless version of the sensor available, so you do have to run a wire to it. The AQY 1 has a fan that comes on every 30 seconds that stays on for 20 seconds that you may find too noisy if you attach it next to your bedroom window. The unit’s specifications state that it should be operated at temperatures above freezing, but my AQY 1 has been operating at temperatures as low as -15° F (-26° C) with no problem.
Configuring the sensor to send data over my wireless network was pretty straightforward, and took me less than 10 minutes. The unit does not have a display panel—you have to go to a web page to see the data. The display page has a nice interface that allows one to see time series plots of all the quantities measured, over any time scale desired. There is currently no way to see other air pollution sensors in your area on their display page; only the sensor you installed shows up.
If you want to learn more about the AQY 1, see Aeroqual’s blog post or their technical product page. The current version of the AQY 1 will be sold to professional customers as well as non-professional customers such as weather enthusiasts. Aeroqual offers a standard one-year factory warranty. If you are interested in purchasing an AQY 1, contact email@example.com for exact pricing, and Include the promo code WUAQY.