Cumulus Support

I've looked through the posts to find a number of topics around this subject but all seem to have a failure mode of 0% Humidity readings. Mine seems to have a problem in that it has been reading 100% for the last few days. Now it has been very foggy and misty around here and the local METARS (Liverpool and Manchester Airports) were reporting 100% or close. However today is a bit fresher with a breeze and the same METARS are reporting high 80s to low 90s. I still have 100% - Anyone seen anything like this? Perhaps it's time to clean out the shield again - only done at start of August.

Stripped down the temp/humidity screen and nothing much in it but at least the humidity went down to 98% this morning - so I guess I will have to wait for some really dry weather to see if there is a problem.

Mine is failing, in that its range has become severely reduced. It's always been a bit dodgy with low readings (less than 50%) but now seems to be constrained to a max of about 87% - even in the fog we had over the weekend and earlier this week. I have a replacement chip, but haven't had the chance to fit it!

Phil, I think the Vue uses a Sensirion T/H sensor similar to the Pro2. The sensor membrane can be subject to contamination. Sensirion do have a routine to try and return to calibration. First wash the chip in distilled water, then...

1.4 Reconditioning Procedure
As stated above extreme conditions or exposure to solvent
vapors may offset the sensor. The following reconditioning
procedure may bring the sensor back to calibration state:
Baking: 100 – 105°C at < 5%RH for 10h
Re-Hydration: 20 – 30°C at ~ 75%RH for 12h

http://www.sensirion.com/fileadmin/user ... eet_V5.pdf

Thanks Mark - looks a rather time consuming process. It's come off 100% now and is getting back to values close to the two Metars (Manchester and Liverpool) - still reading a bit higher than either but I do live on an area called "The Moss" - it's probably called that for a reason!