## Choosing Sensors 

Often the first step is to look for a sensor for what you're hoping to measure. In the community posts below, we're collecting info on different kinds of air quality sensors, and their:

* cost
* sensitivity/accuracy
* links and documentation

Can you afford a sensor? Can it detect what you're looking for? Where can you learn more about it?

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### Posts about choosing and evaluating an air sensor

[notes:grid:air-sensor-eval]

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### Expected ranges and useful detection limits for pollutants of interest

This [table](https://www.epa.gov/sites/production/files/2016-06/documents/air_sensors_webinar_slides_06-29-16.pdf) from an EPA [Air Quality Monitoring and Community Science webinar](https://www.epa.gov/sites/production/files/2016-06/documents/air_sensors_webinar_slides_06-29-16.pdf) lists the six criteria air pollutants and a couple additional pollutants, with background levels you might see in the environment in the “Range to Expect” column and useful detection limits for sensors.

<img style="width: 50%; height: 50%" src="https://publiclab.org/i/41935?s=o" alt="pollutant ranges">

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## Wikis about air sensors

[wikis:air-sensors]

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## Air sensor projects

Public Lab pages and posts tagged `air-sensor-projects` will appear here

[nodes:air-sensor-projects]

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## Questions

[questions:air-sensors]

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## Further reading and resources

+ Environmental consultant Tim Dye’s “[4 questions to ask before buying an air quality sensor](http://tdenviro.com/wp-content/uploads/2017/09/4-questions-when-buying-air-sensors.pdf)” neatly summarizes what to consider when choosing an air sensor. 
+ [Snuffle.org](http://www.snuffle.org/doku.php?id=start): lots of information on low-cost sensors for various air pollutants.
+ [Air Quality Sensor Performance Evaluation Center (AQ-SPEC)](http://www.aqmd.gov/aq-spec/evaluations): from the South Coast Air Quality Management District, this program tests and evaluates air sensors “in the field, under ambient conditions, and in the laboratory under controlled environmental conditions.”
+ [Air Sensor Toolbox](https://www.epa.gov/air-sensor-toolbox): from the US Environmental Protection Agency, this toolbox includes guidance on how to use air sensors and their data, plus information on sensor performance and evaluation results.