Recently I encounter a very high failure rate in our aircraft's aircon duct sensor. It may be due to high humility and the aircon package's water separator was unable to extract the water.
Modification of aircon pack is not a option. So that leaves the improvement of the temperature sensor.
Does anyone here have experience this before? What can be done on the sensor to prevent water seepage into the sensor tip?
I thought of laminating the sensor tip, as this is only area that water can seep through and shorting the whole sensor. But I don't know where to start. Can anyone offer some advice?

Not sure if this method is done, but would a thermal conducting compound applied to the sensor help? I think that if a protective coating is applied to the sensor to protect it from moisture, and at the same time insure the sensor can detect the temperature accurately may be worth considering.

Here is one manufacturer of such products:
http://www.chomerics.com/

I found several others by searching for "thermal conducting compound"

Hope this helps.