Cumulus Support

I have just noticed on a very high dew point day that my weather station reading for humidity is off by approx 1/2 of other local stations. Can anyone give me an idea how to correct it. it is somewhat of an embarrassment consider this is the day from hell with high humidity.

You can try to put calibration settings into Cumulus, but if it's off by a very long way it may be faulty and you are unlikely to get good readings anyway. You could perhaps take the transmitter apart and try to clean the sensor.

Hi,

The problem with humidity measurements is that they limit at 100%, so if the reported value has drifted the "wrong" way then little can be done. But anyway, if it's drifted significantly then it will probably continue to do so.

The "Fine Offset" (manufacturer) external transmitter box (which I believe you have) is normally glued together, but it can be prised apart (if out of warranty). There's lots of information and photos in the "sticky" ("photos of....") threads at the top of the Fine Offset section of this forum. But note that FO have changed some of the components (including the humidity sensor) since some of the earlier photos were taken.

Replacement humidity sensors have been difficult to source (and replacement transmitters are also a "can of worms") so the best option may be to exchange the humidity sensors in the outside transmitter and the Console (the indoor value would then be wrong of course), or from a spare/broken transmitter/Console. The exchange is not something I've done, but was reported as successful by one member.

Cheers, Alan.

thanks for the info and the suspected outcome. I have been thinking of a station replacement in the future, so this will just be another reason to do so.