I'm a software developer (although math isn't my strong point). I've developed a device to monitor/control my clothes dryer by monitoring the intake air's humidity & temperature, and the exhaust's humidity and temperature. The plan was to compare the exhaust air's humidity against the intake air. Once the humidity in both was around the same, it would mean that no more moisture is evaporating from the clothes, ie: they're dry.
Unfortunately its not that straight forward. the air coming out of the dryer is much hotter, and because the sensor is giving me relative humidity values, I cannot compare it to the intake humidity (which is room temperature).
I'm looking for a formula that will allow me to compare the two humidities, taking their temperature into account. An "absolute" humidity I guess, or literally the amount of moisture in the air.
I've tried a couple of formulas I've found online but I'm not getting readings that look valid.
Note that the value doesn't need to be an official, absolute humidity value, it simply needs to allow me to compare the intake and exhaust humidities, at different temperatures (but everything else, such as air pressure, etc... being equal).
(Please feel free to suggest a more appropriate tag)