Humidity Sensor conversion factor

[rleyden]

I bought the temperature and humidity sensors to control a small green house.
The sensors work fine and are responsive. However, the conversion factor to % relative humidity seems wrong( %RH=value*0.1946-41.98). It reads ~50% in my house, which is plausible. When I gently breathe on it, the reading goes up to 150%, not possible

I can think of a few ways to generate a calibration curve but I was hoping someone can give me a better equation.

Rich

[Alex]

Looks like you might have either misplaced your parenthesis or made a typo in your post. Either way the conversion formula is:

RH (in %) = ( SensorValue x 0.1946 ) – 41.98

Is this the formula you are using? I would assume it is because your result would be a bit further off than what you stated.