Hello everyone,
I’ve been using an I-9PSL air quality monitor for about a year now. Recently, I decided to add a second I-9PSL, as well as an outdoor monitor (O-1PST). After setting up the second I-9PSL this week, I noticed its readings were significantly different from my original unit. This led me to attempt calibrating the CO2 readings, hoping the other values might stabilize as well.
To do this, I placed both indoor monitors (the two I-9PSLs) inside my shed. The shed is not insulated—it’s basically wooden planks nailed together with gaps between them, allowing the outdoor air to flow freely. The outdoor monitor (O-1PST) is mounted just outside the shed, about 1 meter away from the two indoor monitors. If you stand in the doorway, you can see all three monitors.
I left the two I-9PSLs in the shed overnight and performed a CO2 calibration for all three monitors simultaneously. Interestingly, the CO2 values for the two I-9PSLs aligned perfectly after calibration. However, the outdoor monitor (O-1PST) still shows a difference of approximately 100 ppm. Given the open and windy conditions of the shed, I expected the CO2 readings to be roughly the same. Am I wrong in assuming this?
In addition, the PM2.5 and TVOC readings for the two I-9PSLs remain inconsistent. These monitors are positioned just 10 cm apart, so I would have expected their readings to match closely. How can I recalibrate PM2.5 and TVOC for these devices?
When comparing the PM2.5 and TVOC readings of all three monitors (the two I-9PSLs and the O-1PST), it’s clear that one set of values stands out as inconsistent with the others. Something seems off here.
Any advice or insights on this issue would be greatly appreciated!
Thanks in advance!