Support Forum (EN/FR)

Velleman Projects
It is currently Tue May 21, 2013 11:15 am

All times are UTC




Post new topic Reply to topic  [ 4 posts ] 
Author Message
 Post subject: Accuracy of the VMB1TS
PostPosted: Wed Jan 18, 2012 9:51 pm 
Offline
Active Poster
Active Poster

Joined: Wed Mar 16, 2011 10:05 pm
Posts: 26
Location: Antwerp, Belgium
I have 3 vmb1ts sensors whereof the accuracy is bad. I have to calibrate the sensors on the TC several times a week.
The measurement keeps changing between 17 and 23°C while it should be 21,5°C.

I found this topic covering the same problem, but there aren't any solid solutions there.

Are there other people experiencing these problems and is there anyone with a solution?


Greetings


Top
 Profile  
 
PostPosted: Thu Jan 19, 2012 8:02 am 
Offline
Velleman Support
Velleman Support

Joined: Fri Dec 08, 2006 8:09 am
Posts: 34
Location: Belgium
The sensor can be placed too close to a heating source.
Air flow can also be a reason for the fluctuation, sometimes from inside de wallmounted box.


Top
 Profile  
 
PostPosted: Tue Feb 07, 2012 5:43 pm 
Offline
Expert
Expert

Joined: Wed Apr 29, 2009 5:10 pm
Posts: 238
Location: Grenoble (France)
since few days I check my temperatures in many room (http://teo-tea.hd.free.fr) and I think WMB1TS aren't accurate :evil:
My first experience was (1 alcohol temp sensor + 1 electronic sensor) near VMB1TS : two first are OK but VMB1TS shows big difference.
In fact, we could change offset but not gain : f(x) = ax+b where b = offset, x is raw temp and f(x) should be real temperature

Then, always with the same temperature placed near WMB1TS (Salon) shows me it has a gain too big (06 february, ext temp : -7°C, VMB1TS on a wall contigous to exterior) : 19°C(T) = 19°C(Velbus)
24°C(T) = 25,5°C(Velbus)

My question is now :
1) can Velbus upgrade VMB1TS with a gain parameter :?:
2) how can we correct this (without self-programming) :?:

For information, I've got 11 VMB1TS (on website it miss external one and office one)
PS: I feel like having "Hubble telescope" in my house :cry:


Top
 Profile  
 
PostPosted: Thu Feb 16, 2012 9:57 am 
Offline
New User
New User

Joined: Tue Sep 13, 2011 9:29 am
Posts: 7
I'm experiencing the same problems here, fortunately temp in my home only fluctuates in about -1 to +1 °c around 21.5°C so I calibrated the offset at that 21.5°C. Gain starts to be inaccurate when temp rises above +2°c of -2°c...


Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 posts ] 

All times are UTC


Who is online

Users browsing this forum: No registered users and 0 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group