Last Saturday when down in my basement my five month old Sensorcon Inspector
carbon monoxide detector was displaying 22ppm on it's LCD. I was shocked because no one but me was home, I have no standing pilot devices in the basement any longer, the mod-con is externally vented with no call for DHW for hours... no one was using the oven/stove- all in all- no combustion was going on inside my house for hours before I noticed this reading.
I decided to take the meter outside to clear the reading then go back inside and investigate.
Upon exiting the house- instead of lowering- the reading went up to 23ppm, then 24ppm as I moved a bit farther from the house. I then walked a few houses down the street with meter in hand- it varied between 23-25ppm. I left it out on my patio table all afternoon, a couple hrs later it went back down to 17ppm, then 9ppm and eventually back to 2ppm and 0-1 ppm that evening and by that time the basement and house were back down to 0-1ppm too.
FWIW- I haven't used the Sensorcon during the summer- I purchased it in Feb where the ambient outdoor CO is usually 0 or maybe 1-2 briefly. I've never take outdoor summertime CO readings before.
Has anyone seen something like this 22-25ppm reading outdoors in the open?