Problems with MD3020E humidity sensor around freezing temps?

[johnnyt]

In recent days the temp outside where I have an MD3020E sensor giving me trouble is swinging slightly above to slightly below freezing, with humidity levels generally above 85%.

I noticed my outdoor humidity sensor has had readings of between 33 and 40 over the past few days when the humidity was much closer to 90% - 100% outside.

Each "valid" (but not inacurate) reading was followed by hours of "???" readings, meaning my HA has been acting on bad advice. Right now the reading is 95, which is more accurate. Temp outside is slightly below freezing.

Ignoring bus reliability issues for the moment, do these sensors cease to work at certain temperatures or humidity levels?

On a potentially related matter, what's the issue with "35" being a bad reading according to posts (and features) in mcsTemperature?

[Midon]

The temperature should not affect the humidity reading significantly. If you look at the HIH3610 humidity sensor's specifications, you will see that it is good for down to -40 and that temperature only affects the accuracy a small amount.

The "35" issue is an artifact from some older TEMP05 software. This issue is not present in TEMP08 (that anyone has ever informed me about anyway!).

Mitch

[johnnyt]

Until today, the past few days have seen at or slightly above freezing temperatures w/ low (mid 30's) humidity outside, and the humidity readings of my outdoor MD3020E has been providing only the occasional good reading followed by hours of "???" readings.

Today, as we experience one of those days where the temp has been dropping and the humidity has returned to 80+% through the day, I can't seem to get a single bad reading from my outdoor humidity sensor.

Could to the rate/direction of temperature change along with a relatively low humidity reading at or around freezing? Has the humidity sensor on my MD3020E simply become defective?

[johnnyt]

I would mention that, until recently, mcsTemperature was treating 35 as a bad reading. Now it has an option to ignore that Temp05 issue (or not, for backward compatibility)