Learn more about the information provided in this tool, including prices and accuracy ratings.
Monitor prices
This online tool only covers devices that cost less than AUD$10,000. Prices are given in AUD and are indicative only; current seller prices may differ. Prices are also subject to changes in exchange rates.
Unless otherwise stated, the prices given are for the purchase or subscription costs of the monitoring units only. Prices do not include other costs such as data-related subscription fees, handling, shipping or customs fees.
Some manufacturers only offer units on a subscription basis. For comparison purposes, we’ve priced these units based on the approximate cost of a 2-year subscription.
Be sure to confirm unit prices with sellers before you buy. It’s also a good idea to ask sellers if they offer discounts for multiple units.
Monitor type
Depending on your monitoring project, you may need an indoor or outdoor (stationary) device. Tick the box for ‘indoor’ or ‘outdoor’, depending on your needs.
Note that if a monitor is only specified for outdoor use, it’s not a good idea to use it to monitor indoor air as well. To choose from monitors suitable for both indoors and outdoors, tick the box for ‘indoor & outdoor’.
You can also choose from a growing number of hand-held portable devices. This category includes a small number of devices that can even be mounted on vehicles.
Pollutant types
The online tool also allows you to select for devices that measure these types of pollutants:
PM – particulate matter. Small inhalable particles or liquid droplets in the air, including dust dirt, soot or smoke from many sources, including fuel burning. PM sized less than 2.5 microns (PM2.5) poses the greatest health risk. This online tool allows you to select devices that measure PM1, PM2.5 and PM10.
NO2 – nitrogen dioxide. This gas is a respiratory irritant caused by emissions from vehicles, industry and burning gas indoors, for example, when using gas stovetops or unflued gas heaters.
SO2 – sulphur dioxide. Released when fossil fuels are burned by power plants and at other industrial facilities, sulphur dioxide is a gas that can harm the respiratory system.
O3 – ozone. The main component of smog, ozone is a gas that forms when emissions from traffic and industry react with sunlight. Ozone at ground level is harmful to your health.
CO – carbon monoxide. A gas you can’t see, taste or smell, carbon monoxide is highly poisonous and can cause death. Outdoor heaters, lanterns and charcoal barbeques are common sources.
H2S – hydrogen sulfide. A harmful but invisible gas with a rotten-egg smell, hydrogen sulfide has many sources, natural and human-caused. Sources including sewage plants, large pig farms and industry.
CH4 – methane. High levels of this gas are harmful to health. Most methane pollution comes from agriculture and the oil and gas industry.
NH3 – ammonia. A colourless gas that smells of drying urine, ammonia can be harmful at high levels. It’s caused by emissions from agriculture, petrol vehicles, waste disposal and fertiliser production.
CH2O – formaldehyde. A colourless gas released by some industries and by burning fuels, formaldehyde irritates the eyes, nose and throat and can cause allergies. It’s also carcinogenic.
NO – nitric oxide. A colourless gas with a sweet odour, nitric oxide is a respiratory irritant that’s formed from burning fuels, including those burned by coal power plants and vehicles.
VOCs – volatile organic compounds. This broad class of chemicals that evaporate at room temperature includes many compounds produced by humans. Some VOCs have short- or long-term adverse health effects.
Accuracy, the ability to hit a target, refers to how well sensor measurements agree with highly accurate reference instruments.
Accuracy
This online tool provides accuracy information from independent evaluations, where they are available. These results are given as R2 values, a statistical term. The closer the R2 value to 1, the stronger the agreement and the greater the accuracy, with 1 being a perfect agreement.
R2 values provided in this tool are sourced from field evaluations by:
- California’s South Coast Air Quality Management District (AQMD) Air Quality Sensor Performance Evaluation Center
- US Environment Protection Agency
- Cavaliere et al. (2018)
Unless otherwise stated, the R2 values provided are for 24-hour averages.
Be aware that accuracy evaluations, even independent ones like those cited here, can provide biased statistics due to fluctuating levels of pollutants and changing seasonal conditions.
Data handling
This tool provides information on how devices transmit, store and display data.
- Data transmission – WiFi is available for many low-cost sensors. Some manufacturers offer a wide range of other transmission options, including Bluetooth, satellite, 3G/4G and low-power wide-area network (LoRaWAN). In models that store data on the device, for example, on an SD card, you’ll need to retrieve it manually.
- Data storage – Some low costs sensor devices store data locally. Others use central servicer or more commonly the cloud to store data.
- Data display – On-device displays, website or app data visualisation are some common ways to view air quality data. If your model stores data locally on the device itself, you may need to download the data and view it on a computer.
Power options
The tool also provides information on the power supply options for devices. Many low-cost sensor devices can be directly plugged into mains power; some also come with adaptors and USB power supplies. Batteries are available for some models, and solar is an option for many outdoor monitors.
Calibration
This tool provides information about how some devices may be calibrated, where this information is available. Some sensors are factory-calibrated prior to sale, meaning they’re checked to ensure their measurements compare well with a known, certified standard. A number of manufacturers also offer the option to return sensors to the factory so they can be recalibrated. If accuracy is important to your project, you may need to field-calibrate sensors by co-locating the device with a reference instrument. Check with the manufacturer to understand the calibration process for the device you intend to buy.