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A comment on I Bought a CO2 Monitor, and It Broke Me. Parent comment

Re:I Bought a CO2 Monitor, and It Broke Me by Buttons840 on Friday February 03, 2023 @10:39PM (#34651210)
I have a TIM10 that was once reporting negative CO2 levels one spring with the windows open. I'm not sure what I think about it. It's not a scam product by any means, it can definitely tell when someone is in the room or a window is opened or closed. I needed the space and unplugged it awhile ago and just don't worry about CO2 levels currently.
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Re:I Bought a CO2 Monitor, and It Broke Me by unlikelymordant on Friday February 03, 2023 @11:11PM (#34651427)
My understanding is that some co2 sensors assume the minimum value seen over the last 30 days is 400ppm as a calibration. This could possibly explain a negative value if the sensor has been in higher co2 environment for some time, and is suddenly exposed to the outside.
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Re:I Bought a CO2 Monitor, and It Broke Me by Buttons840 on Saturday February 04, 2023 @04:25AM (#34653067)
You're right. The instructions say to place the sensor outside for a time to calibrate it, which I never did.
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Re:I Bought a CO2 Monitor, and It Broke Me by lovemenot on Friday February 03, 2023 @11:16PM (#34651460)
Does it require callibration?
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Re:I Bought a CO2 Monitor, and It Broke Me by schmichael on Saturday February 04, 2023 @12:33AM (#34651844)
Yes. All consumer CO2 detectors I’m aware of take periodic calibration.
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Re:I Bought a CO2 Monitor, and It Broke Me by bookofjoe on Saturday February 04, 2023 @05:29PM (#34659101)
Not Aranet4
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Re:I Bought a CO2 Monitor, and It Broke Me by schmichael on Tuesday February 07, 2023 @10:35AM (#34694126)
Yes you do. Once a year: https://aranet.com/faq/

Their data sheet also advises calibration if used at “high elevation.”

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