We have several PurpleAir "Touches" and our new Pixel works as well as they do in accurately measuring air quality. The Pixel will come in very handy when we travel. It looks cool as well ;^)
Compact and very responsive to air quality change.
No wifi. The colors, green, yellow, orange, red, may overlap in the display. I guesstimate the reading. If it's plugged into my PC, I use the "Purple Air Tools", and my visual reading may be 10-20 points lower than the digital reading. YMMV.
The Pixel has seven brightness levels, bright to very bright. It's too bright for my room at night, so I cover one side of the Pixel with Scotch Magic Tape.
We bring the Pixel camping to test the air inside and outside the camper and it helps us plan our day (games/reading inside or hiking and exploring outdoors). On our last trip, the smog from Atlanta GA made it's way north where we were camping and the air quality registered as red outside while inside the camper was green (HEPA filter runs 24/7). After the storm, the air quality showed us green and it was safe to go outside. If my asthma kicks in, I check the air - and sure enough - air quality is poor. We have smog at times where we live. This morning the Pixel color was magenta - quickly went back inside where Pixel showed green. Very useful little device.
Four stars only because it only works as designed: The actual fulfillment of purpose is more nuanced:
* If it had a male USB-C could it just be plugged into a phone?
* How much more expense or increase in form factor would there be if it displayed numbers instead of or in addition to colors? Colored numbers? This is obviously critical because AQI 49 is green and 99 Is yellow, etc. (I like that blends colors as with the rest of the PA communication system.) I see a review that mentioned this issue from 10 months ago...
* The unit seems strong and solid, perhaps even if dropped... The weak point of course is the USB... Some type of tiny protector for it would be great... A custom case?... I would love to wear it around my neck, could be beneficial for the brand if it's colored purple...
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There's a larger issue of course which is the responsibility of EPA: the current rating and color scale is completely inadequate as it simply makes things seem better than they are. A small part of the reason is that the colors abruptly shift, and I appreciate that you guys do that blending thing. But according to EPA, AQI 62 is at the safer end of Moderate... 62 is also the recommended maximum by the WHO for 24 hours of exposure.