RH shows approx. 9-10% RH too much

My first Ruuvitag, sitting outdoors, has given up,
it now shows all the time approx. 9-10% RH too much.
It started in winter when I discovered it was 100% RH.
I took another Ruuvitag and placed next to it.
Changed the batteries between them, but no change.
Had them indoors for 14 days but no change.
I have a picture from May, where it still shows
100% RH at night.
So now comes Espruino on it, and a sensirion sensor
Purchased on 30/6-2017


Thanks for the data. Just to clarify, was the tag originally giving you good values and has the humidity sensor gone bad later? Was it a sudden event, or has it been a gradual shift?

It has worked fine until this winter.
I became aware of it as the view in my greenhouse
was below 100% RH, and it felt more humid than
Unfortunately, I can’t go back beyond March,
when my raspberry gave up working on wireless wifi.
I tried with a new image, with the same result, so
now I run the wired network.

Thanks for the additional details. Bosch is currently investigating a few units with similar symptoms in their laboratory, we’ll inform them of your tag. Please keep the tag for now in case it is needed for the failure analysis.

I will do. Thank you.

I have similar issues.

@otso Do you want me to send you a malfunctioning tag.

Maybe this information will add some insight FAQ:-Temperature,-humidity-accuracy

Thanks for the offer, the lab has enough units for investigation for now. Please keep the tag for now, we’ll know more about the issue in next few weeks.

Today it is up to 18% RH too high.

Just to let you hnow.

I have taken my ruuvitag out of service and taken out the battery, put it in a box with another ruuvitag that measures temperature and humidity.
The temperature is between 20 and 22.5 degrees Celsius and humidity is just under 50% RH.
They must be there 1 week to see if my ruuvitag will rehydrate.

Then it was that I found that the ruuvi station on the iphone shows +00:00 while my android shows GMT + 02:00.


The clocks are now shown same way in iOS as in Android, the update is in next few releases. Thanks for the report.

Anything new from Bosch?


So far we haven’t been able to find a root cause for the high offsets in some devices. Please contact sales@ruuvi.com, link this post and we’ll figure out the next steps

I just tested my outdoor sensor, with one of the new sensors I’ve got. It doesn’t draw well.
My outside sensor is “name: Test1”. which I replaced with the original outdoor sensor.
The new sensor that I got the other day is “name:”.
They are located next to each other.
The next thing I want to test is my sensor in the greenhouse. I have the feeling that it has also gone whistle.
To me it looks like they can’t stand being over 80% RH for a long time.

So I can’t use them in my automation as I can’t trust them.

Yes my feeling was right, RH for my greenhouse is also too high.
My sensor is “name: Drivhus”

Hi Frida,

I am not sure if I understand last one (and previous) correctly. RH in greenhouse is between 87-90% but what is the level you are comparing it?

I got some new ruuvi tags, of which I have taken one of the new ones, and first I placed it by the outdoor ruuvi tag.
The new sensor has the green color and the name “name:”
My outdoor sensor has the red color and the name “name: Test1”
The new sensor is around 90% RH while the outdoors is at 100% RH.

Then I moved the new sensor to my greenhouse.
The new sensor has the green color and the name “name:”
My greenhouse sensor has the blue color and the name “name: Greenhouse”
The new sensor is around 90% RH, while the greenhouse is at 100% RH.

I have 2 new pictures where I also compare the new sensor with the existing one.
My bedroom seems to be ok.

My bath I think the difference is starting to get too big, the difference is now 5% RH.

Sorry, but I still don’t fully follow the explanation. I also could not find name “greenhouse” but you probably meant “drivhus”?

“the new sensor is around 90% RH while the outdoors is at 100% RH”
Do I understand correctly that you have now placed new sensor also outdoors and old one is showing 100% and new one 90%? Both are close to each other?
If outdoor sensor has been long time outdoor have you checked if there are humidity condensed inside?

I have several sensors outdoors and when temperature has been around +2…13C humidity levels has been between 95-100%. Currently in my greenhouse humidity has been 100% for very long time (closed space, air is not moving) and water also condensed to plastic greenhouse frame.

Yes, “greenhouse” = "drivhus

Yes both side by side.
Took both of them to the kitchen table, and opened them, took a picture. There is no moisture on the sensors.
The indoor difference in RH is 8% RH.

Yes, but in my greenhouse, I have forced ventilation that I had hoped to be able to automate with these sensors, but because they deviate too much over time, I can’t trust them.

The temperature difference of 1C is also a bit too much i would say.