Outside Humidity Wrong

[The Dalek Hunter]

I have had a Davis Vantage Pro 2 since 2018. I feed (amongst others) AWEKAS
I have been using WeatherCat on a Mac Mini - https://wx-watch.co.uk but last year started using Cumulus MX with a WeatherLink Live and then an Ecowitt Gateway.

https://longsuttonweather.co.uk and https://longsuttonweather.co.uk/ecowitt/

Last night I got an email from AWEKAS saying due to my outside humidity being way too low compared to nearby stations uploading of my outside humidity would be blocked for the time being.

Looking back it seems always to have been on the low side and is certainly low compared to the Ecowitt Station.

Batteries in the sensor array are reported as being fine and all other data from it seems ok.

Any ideas what could be causing this?

For the moment I have gone into the calibration setting in the Davis Console and added an offset and also added an offset in the CMX calibration settings to set it to the Ecowitt reading.

[freddie]

Looks like you may need a new temperature and humidity sensor

[The Dalek Hunter]

Is it easy to replace - mine is a Wireless Vantage Pro 2

Is this what I need??

https://www.weathershop.co.uk/davis-ins ... nsor-board

Since I have calibrated it, its seems to be producing sensible humidity data!

[freddie]

Yep that's the replacement part.
Your calibration is just an offset, though. It looks as if your sensor has limited range. I would carry on comparing for a few weeks before making a decision.

[dazza1223]

i just got my my vp2 do i need to calibration or ofset on mine?

[The Dalek Hunter]

Ok - I have ordered one!

Are there any (easy to follow) online tutorials on how to change the sensor?

[freddie]

Should be calibrated pre delivery. My temp/hum sensor is 5 years old now and hasn't needed calibrating. In my experience the humidity sensor reads a little low when the ambient humidity is above 90% and a little high when the ambient humidity is below 70%. I've had three sensors in the 14 years I've had my vp2, and they've all behaved like this.

[dazza1223]

ok freddie thank u you know everyone like tweaking

[The Dalek Hunter]

Ok - I realise that I have to shutdown CMX and put the Davis Console into setup mode and as I have a Davis WeatherLink Live as well I presume I unplug it from the mains and remove the batteries before I start to install the new sensor. Then after installation to check all is working I take the Console out of setup mode and check all is well. Now this will perhaps produce some spurious results as I get the sensors back up on the roof again so the question is how do I purge the data from my USB data logger before restarting CMX?