## 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? ### Posts about choosing and evaluating an air sensor [notes:grid:air-sensor-eval] ### 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. **** ## Wikis about air sensors [wikis:air-sensors] ## Air sensor projects Public Lab pages and posts tagged `air-sensor-projects` will appear here [nodes:air-sensor-projects] ## Questions [questions:air-sensors] ## 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/): 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. ...
| Author | Comment | Last activity | Moderation | ||
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| zengirl2 | "@kkoerner so cool to see this post as well as the guts of the air sensor. Looking forward to the update on the results. " | Read more » | almost 6 years ago | |||
| lindarose11 | "Very helpful advice in this particular post! It’s the little changes that make the largest changes. Thanks for sharing! Download Zombie Diary APK Mod " | Read more » | almost 6 years ago | |||
| kitchen | "Great article, thanks for the insight. " | Read more » | almost 6 years ago | |||
| jiteovien | "@pdhixenbaugh If I understand your comment correctly, that is exactly the point I am trying to make. Perhaps, we need to create our own AQI index i..." | Read more » | almost 6 years ago | |||
| jiteovien | "@jeffalk PM concentrations do not have meaning if there isn't an understanding of how the concentrations affect health and well being. Perhaps I us..." | Read more » | almost 6 years ago | |||
| kkoerner | "@zengirl2 I agree, the ambient network can be a little scarce in Philly, we have six PM 2.5 monitors measuring at different intervals. Here's some ..." | Read more » | almost 6 years ago | |||
| pdhixenbaugh | "Isn't he doing not a 24 h average, but a week average in this case? That sounds like it would have merit. One thing I'm legitimately curious about..." | Read more » | almost 6 years ago | |||
| shinchan | "Pretty! This was a really wonderful post. itudomino " | Read more » | almost 6 years ago | |||
| jeffalk | "jiteovien: I realize you have put a considerable amount of effort into your project and are trying to do an excellent job. I believe you are exhib..." | Read more » | almost 6 years ago | |||
| amirberAgain | "Here is a google Colab recreating this: https://colab.research.google.com/drive/1rADQ9hbIEP-DO1hsLpVWAOz2wJu4SuwM " | Read more » | almost 6 years ago | |||
| jiteovien | "Hey @jeffalk . I am well aware that the Purple Air data sheets are logged in units µg/m3. I referenced airnow.gov that has conversion calculators f..." | Read more » | almost 6 years ago | |||
| warren | "OK interesting and now it's green again, and i guess because of averaging, the spike doesn't appear as high anymore? @jeffalk does this seem rig..." | Read more » | almost 6 years ago | |||
| warren | "Oh wow, I literally saw the dot change from yellow to orange as I watched the map! You can see the spike too: " | Read more » | almost 6 years ago | |||
| warren | "Just a note that at 12:42 today (friday) two people with leaf blowers went by clearing the sidewalk and there was visible dust kicked up. Curious t..." | Read more » | almost 6 years ago | |||
| cheapmcmbelt | "MCM Medium Stark Lady Rabbit Odeon Studs Backpack In Burgundy Shop www.mcmbackpacksoutletonline.com Cheap MCM Backpacks Outlet Store and Buy MCM ..." | Read more » | almost 6 years ago | |||
| jeffalk | "I believe you are not quite correct in the determination of the AQI. First, the downloaded data from purple air gives concentrations, for pm2.5 th..." | Read more » | almost 6 years ago | |||
| jiteovien | "@zengirl2 Nope, I haven't tried a Plume " | Read more » | almost 6 years ago | |||
| kkoerner | "Great overview! Also, if you're looking to test a sensor, there's a chance that SCAQMD AQ-SPEC may test it if they haven't before. They have a list..." | Read more » | almost 6 years ago | |||
| zengirl2 | "@jiteovien I find that there are not many official monitors in Philly either. So, I'm very interested in air monitoring just to see how the numbers..." | Read more » | almost 6 years ago | |||
| zengirl2 | "@jiteovien So cool to see that large testing equipment next to your little Dustduino! Anyway, your need for a waterproof set-up reminded me of work..." | Read more » | almost 6 years ago | |||
| liz | "Hi @mprof9, if you post your project following the template above, people can start asking questions and collaborating! sensor calibration is a big..." | Read more » | almost 6 years ago | |||
| jiteovien | "@zengirl2 The PurpleAir folks say that the sensor come "factory calibrated." I am certainly skeptical of that because its been shown that humidity ..." | Read more » | almost 6 years ago | |||
| zengirl2 | "@jiteovien Ah, this is helpful--what a great testing zone. Interesting to hear how Purple is a bit high on readings too. Did the sensor need to be ..." | Read more » | almost 6 years ago | |||
| jiteovien | "@zengirl2 Yeah, the area the office is is actually near the part of Providence (the port) with the most industrial polluters. See the map below of ..." | Read more » | almost 6 years ago |