I made a uC powered device to control the humidity and temperature of a room. I used sht10 sensor. The room humidity provided with a humidifier. The sensor was working well. When trying to test the device at the target room, I think the mist at the room made the sensor to malfunction. Now the sensor just reads 100% humidity and temperature of ~50 degrees. When I touch the sensor it reads higher temperature (although not true), but the humidity is always 100%, so I think the sensor is not damaged. May I recalibrate the sensor or not. And do I need a special membrane to avoid such problem? May I make a DIY membrane Or I can expose the sensor directly to the mist?. Thanks
The SHT1x sensors can lose calibration if exposed to excess moisture/condensation. Despite this, however, it is not meant to be damaged from excessive moisture and can even be immersed in water (see footnote 13 in datasheet).
From personal experience these sensors normally return to a calibrated state, after being left alone to dry out for 10 hours or so.
If this still does not work you can undergo a reconditioning process. Look at the datasheet here under "Reconditioning". There is a process of baking and then re-hydrating the sensor to return it to calibration.
If the sensor is still returning spurious values after drying out for a day or so it's most likely damaged.
You can purchase filter caps for the sensor, which are available from Farnell, which are not supposed to effect the humidity reading. However, I've never used them personally. http://www.farnell.com/datasheets/48936.pdf