Relative Humidity Calculator

Other Hardware Sensors
1

If I know the :

dry bulb (Fahrenheit)
wet bulb (Fahrenheit)
dew point (Fahrenheit)
Atmospheric Pressure (Millibars)

How I calculate the relative humidity (%) ?

2

Try this link and look at the equations near the bottom of the page.

3

Arctic_Eddie:
Try this link and look at the equations near the bottom of the page.

Thanks for this. .

RH: =100*(EXP((17.625TD)/(243.04+TD))/EXP((17.625T)/(243.04+T)))

EXP value???

4

That's the exponential function. It should be in the <math.h> library. Just #include that at the top of your sketch.