Overall, I like this item and it seems to give reliable readings.
First, there definitely seems to be about 20 second delay at all times.
I can walk behind my running car with the device, roughly 15-20 seconds later, the readings jump to 20-40 ppm.
Walking into clean space seems to be quicker response.
I have had odd moments where my parking garage registers zero ppm.
I've come to the odd conclusion with this device that parking lots have terrible air, even.
Walking through mall parking lot, I got jump to 50ppm on this device, and in my ENCLOSED parking garage, I've never once seen reading above 20ppm.
I've also seen odd moments where the clean air in my home will jump from 0ppm to 3ppm back down to 0.
I'd also recommend that the engineers who developed this device consider de-coupling Max Average button.
Just because I want to clear Max does not mean I want to clear my Average.
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