I recently installed a Flex sensor and it is working well so far. Cool!
But it is clear, and I have read in several places, that fog can cause false-positive readings in these sorts of sensors. I can see how that would happen.
I have my own IoT server polling the Flex periodically and storing live data in a database for later analysis. I would like to add a flag to each record that indicates the likelihood that a given reading might be affected by fog so I can perhaps discount such readings in later analysis.
I have read that fog forms when the air is still and when the air temp approaches the dew point. I am not sure if this is correct. But if so, given appropriate weather information, I might be able to set a “fog flag” on my reading record in the database.
From the BME sensor in the Flex, I see the following info:
BME680: 51.00°F RH: 69.00% Dew: 41.00°F P: 1007.29 hPa AQ: 68.49 ADC: 4.07V
And I would try to use that except that I do not think these values are correct (or even close). For example at the time the BME is saying the temp is 51F, my outdoor furnace temp sensor says 43F. If the temp is that far off, how can (should I) trust any of the other reported values from the BME?
I am not complaining here about the BME. I have read and understood that the conditions under the Flex’s dome are going to be different due, at least in part, to the heat from the sensors and other electronic in there.
And I have read that somewhere, 8 degrees (not sure if F or C) are removed to compensate. But I am not sure about this for temp and have not seen anything about the other values.
Can someone more clearly define what is happening with the values reported from the BME?
Can someone suggest an alternate approach? Am I even on the right track to making a “fog flag”?
Thanks!