BME280 Ambient temperature and PCB temperature

[Myzhar]

Hi all,

I noticed that the temperature readings of the BME280 mounted on my PCB is highly affected by the temperature of the PCB that is always above 40°C.
Is it possible to hestimate the correct ambient temperature?

I also noticed that the humidity is very low (25% versus 65% measured by another sensor), may the heat of the PCB affect it?

The pressure instead seems to be correct and very precise.

Thank you
Walter

[shellywang · Accepted solution]

Hi ,

The BME280 is very sensitive to environment, so self-heating of PCB can influence the measurement.

From HW side, you could keep BME away from component w/ significant self-heating effect, or isolate it, e.g. cut heat conduction via cooper. You could find the details in HSMI https://ae-bst.resource.bosch.com/media/_tech/media/application_notes/BST-BME280-HS006.pdf

From SW side, you could measure the offset between BME and ambient, and subtract the offset in BME reading.