# PM2.5 and PM10 showing almost identical (low) values

**URL:** <https://discuss.blues.com/t/pm2-5-and-pm10-showing-almost-identical-low-values/360>\
**Category:** Airnote\
**Created:** [August 9, 2021, 9:05pm UTC](https://discuss.blues.com/t/pm2-5-and-pm10-showing-almost-identical-low-values/360 "2021-08-09T21:05:42Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![AlberTO](https://avatars.discourse-cdn.com/v4/letter/a/ea5d25/32.png) [@AlberTO](https://discuss.blues.com/u/AlberTO)\
**Post date:** [August 9, 2021, 9:05pm UTC](https://discuss.blues.com/t/pm2-5-and-pm10-showing-almost-identical-low-values/360/1 "2021-08-09T21:05:42Z")

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From 2017 I have been here in Torino (Italy) one of Safecast’s beta testers with their air quality monitoring device using the OPC-N2 sensor by Alphasense. As such I collected a lot of data on PM1, PM2.5 and PM10 along a couple of years.

A few days ago I started with the Airnote, but noted that the readings of the PM2.5 and PM10 are surprisingly similar (in may points even identical!). See an example in the attached image:

 ![Air Quality Panel_Alberto](https://us1.discourse-cdn.com/flex020/uploads/blues/original/1X/a077f181a03dc8e11a851cceeed74d07e030ade6.png)

This seems quite unusual. I wonder if there is something wrong in my Airnote’s sensor or if I am missing something. Your opinion would be appreciated…

Thank you very much and best regards.

Alberto

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**Author:** ![robouden](https://sea2.discourse-cdn.com/flex020/user_avatar/discuss.blues.com/robouden/32/336_2.png) [@robouden](https://discuss.blues.com/u/robouden)\
**Post date:** [August 12, 2021, 2:07am UTC](https://discuss.blues.com/t/pm2-5-and-pm10-showing-almost-identical-low-values/360/2 "2021-08-12T02:07:19Z")

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Alberto,

Thanks for the posting.  
I will check why this is happening.

Regards,  
Rob