BME680 Will high temperature reading affect IAQ accuracy?

[twlawrenceko]

Hello,

We have finished developing BME680 and we do realize our BME680 will have higher temperature reading comparing to real room temperature. I have read many articles that it can be due to heat disipation issue. We have put a ground copper pour under BME680 for quite a big area and NO other components nearby (except capacitor filtering).

We would like to know would the IAQ and other values still be accurate if the temperature and humidity is relatively off?

We have BME680 reading of 30C with room temp of 23.5C and BME680 reading of 39.5% humidity and room humidity of 57%. Since the IAQ and others accuracy is already at 3 (max), so does that mean the values for those are accurate?

Thank you.

[BSTRobin · Accepted solution]

Hello twlawrenceko,

IAQ is calculated within the raw gas resistance.
when absolute humidity changes, the gas resistance would be changed correspondingly even there is no obvious changes with gas concentration.
when temperature changes, the absolute humidity would be changed correspondingly.
In BSEC, there is one parameter to compensate the TH effects towards gas resistance. The purpose is to output nearly the same value of IAQ during such situation.
But the compensation parameter varies with the usage time of sensors. It could not suit for every use-case.

[twlawrenceko]

Hello BSTRobin,

Just to clarify, even with wrong humidity reading (e.g. real humidity 70%, BME680 humidity reading 30%) , since IAQ is based on gas reading, so that means IAQ reading is correct as long as the accuracy is above 0?

Thank you.