Question:Does anyone know why ambient oxygen levels would be higher than the normal 21%?

by sarasage | June 14, 2021 19:11 | #26824


I got 23% O2 readings today (two different monitors) and want to know if this is considered within the normal range? There was also elevated NH3 today. Also, does temperature affect O2 concentrations? Genuinely curious.



4 Comments

Well, first question. Are the two monitors of the same model and were they bought at about the same time?

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Yes, the instruments are the same (4-gas meter from RKI) and are a couple digits away from each other; they were purchased as a group. We keep them calibrated and perform a mini calibration every morning before use.

I had this same result early AM yesterday. A curious finding and am wondering if it is equipment related or if some known phenomena is at work.


Well, there are a couple of options. One is that the calibration standard is off. You'd have to get another instrument to check that out. The other is that there is an oxygen leak in the building. Unlikely. First, is there any source of oxygen in the building? But to be safe, take the instrument outside and see if the values go down. If there is a source of oxygen in the building and they go down alot, call 911 and get out.

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Another good approach is to call the make of the monitors. They would probably have a good idea if this is normal. Regards.

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