Absolute Humidity from BME680

[Tarigura]

We are using the BME680 to measure relative humidity but we have discovered that absolute humidity might work better for our system calibration due to its non dependance on temperature changes. What is the formula that Bosch uses to calculate relative humidity from absolute humidity? Specifically the formula that gives me the values of maximum water vapor pressure so that we can backward calculate the water pressure values from the relative humidity data we get from the sensor using the equation below

Relative Humidity =  (Absolute Humidity) / (Max Water Vapor Pressure at given Temp)

[Minhwan · Accepted solution]

Hello, 

We have very complicated fomular for humidity, and you can check in our API. 

https://github.com/BoschSensortec/BME68x-Sensor-API/blob/master/bme68x.c

There is calc_humidity function. 

We use multiple variables for our humidity. 

In terms of our humidity, please check our datasheet.

https://www.bosch-sensortec.com/media/boschsensortec/downloads/datasheets/bst-bme680-ds001.pdf

Thanks,