Please read the posts in the Announcements section about the current status of Cumulus development now that I have retired

Please read this post before posting

Latest Cumulus release v1.9.4 (build 1099) - Nov 28 2014
Latest Cumulus MX release - v3.0.0 build 3043 Jan 20 2017. See this post for download

Temperature data spikes revisited

Discussion specific to Fine Offset and similar rebadged weather stations
Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Temperature data spikes revisited

Postby Gina » Fri Sep 24, 2010 8:54 pm

I now have two parallel systems from console onwards with common transmitter and outdoor sensors. So both consoles are receiving the same data packets from the transmitter. Both systems are using G-Weather running under Linux Mint 9. These upload their data to parallel web sites on my server. Here are the temperature plots for today - note the difference in the spikes!
24hrs-Temperature-a.png
24hrs-Temperature-b.png

This would tend to show that the problem is not entirely at the transmitter end though a couple of spikes are common. This looks like the start of a whole new investigation.

The intention of this setup was to let me develop G-Weather without interrupting the main weather site. This difference was quite a surprise!
You do not have the required permissions to view the files attached to this post.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.

geoffw
Posts: 423
Joined: Fri May 08, 2009 3:12 pm
Weather Station: Oregon WMR200
Operating System: Windows 10
Location: Pembrokeshire West Wales UK
Contact:

Re: Temperature data spikes revisited

Postby geoffw » Fri Sep 24, 2010 9:27 pm

Looks like you're going to have to investigate influences on the receiver/console! Is anyone else using two receivers from one station who can compare results?
Geoff
Image

User avatar
daj
Posts: 2041
Joined: Tue Jul 29, 2008 8:00 pm
Weather Station: WH1081
Operating System: Pi & MX
Location: SW Scotland
Contact:

Re: Temperature data spikes revisited

Postby daj » Fri Sep 24, 2010 9:38 pm

I have two receivers for mine. I use one for live and the other to feed Cumulus 2 occasionally.

I've never compared the two consoles /data closely. Maybe I should if that would help
David
kippfordweather.uk
Cumulus MX & Raspberry Pi

User avatar
Super-T
Posts: 790
Joined: Tue Sep 09, 2008 3:37 am
Weather Station: wh-1081
Operating System: Weather Laptop - Windows 10 Pro
Location: Auckland, New Zealand
Contact:

Re: Temperature data spikes revisited

Postby Super-T » Fri Sep 24, 2010 11:18 pm

If it's so easy to add another transmitter then do your neighbours have a similar transmitter Gina?

User avatar
Ned
Posts: 224
Joined: Mon Jul 19, 2010 11:15 am
Weather Station: WS2083 aspirated
Operating System: Win 10
Location: Auckland NZ
Contact:

Re: Temperature data spikes revisited

Postby Ned » Fri Sep 24, 2010 11:42 pm

I had problems with temp spikes under windy conditions after resiting the wind sensor away from the transmitter, needing a 15m extension cable. They have been tamed using EWTempdiff (set to 0.5) in cumulus.ini. which ignores any spike greater than 0.5°C. It works great, but in particular circumstances (spike exactly equals EWTempdiff during a temp trend in the opposite direction to the spike) the graph can get stuck on a flat line until the temp gets within range again. It's only happened twice so far, and I fixed it by restarting Cumulus.
I've got a CAT5 cable ready to be installed, which I hope will reduce spikes at source.
Gina, are your spikes occuring with shielded or unshielded cables?

Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Temperature data spikes revisited

Postby Gina » Sat Sep 25, 2010 8:15 am

daj wrote:I have two receivers for mine. I use one for live and the other to feed Cumulus 2 occasionally.

I've never compared the two consoles /data closely. Maybe I should if that would help
It would certainly be interesting, thank you :) Maybe turn off the Cumulus spike removal if it's on.

Super-T wrote:If it's so easy to add another transmitter then do your neighbours have a similar transmitter Gina?
No, I'm pretty sure of that.

Ned wrote:Gina, are your spikes occuring with shielded or unshielded cables?
I have a shielded cable from the wind sensors though the shield is not connected to the tx unit ATM (using the new unit, unmodified). Some spikes appear to be coming from the transmitter but not all of them.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.

goldrush
Posts: 183
Joined: Mon Oct 27, 2008 4:50 pm
Weather Station: Fine Offset WH1081
Location: Aberdeenshire, Scotland
Contact:

Re: Temperature data spikes revisited

Postby goldrush » Sat Sep 25, 2010 8:28 am

I had a similar problem initially using extension cable to wind sensors.
You should use Cat 5 Twisted pair shielded cable and earth the shield, the special "grounding wire" and unused pairs at one end the transmitter end only, ensuring a good direct "earth" connection.
Image

Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Temperature data spikes revisited

Postby Gina » Sat Sep 25, 2010 11:04 am

Not cat5 but I am using twisted pair screened cable - 2 pair rather than 4 pair - and I had the screen connected to the negative battery terminal of the transmitter unit. That seemed to pretty much cure the spikes at the time. When I swapped the old tx unit for the new, I didn't want to open it up in case there was a fault and I wanted to return it. Now everything seems fine with it I may solder a wire onto the power supply negative, as before. I'm also going to connect it to an earth spike near the Stevenson screen box.

Two hours later... I have now connected the cable screen to an earth spike - a piece of copper water pipe (cleaned off) hammered a foot or so into the ground (the thickness of the topsoil).
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.

Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Temperature data spikes revisited

Postby Gina » Sat Sep 25, 2010 1:51 pm

I have now moved the no.2 console and hung it on the wall that's nearest the transmitter. It's away from computers there and nearer the transmitter. That was about 14:30, for reference. Now to wait and see...
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.

Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Temperature data spikes revisited

Postby Gina » Sun Sep 26, 2010 1:10 pm

Seems the spikes have gone :) Two measures for the transmitter and one for the receiver (one console). viz. Mast "grounded" by a wire from the jubilee clip that fastens it to the fence post to an earth spike nearby and the cable screen (from wind sensors) similarly earthed. Then the new console that seemed to be getting extra spikes was moved away from interference generating computers and nearer the transmitter.
24hrs-Temperature-a0.png

This second plot comes from the console I moved. I may try moving it back later and see if it picks up interference.
24hrs-Temperature-a1.png

I had noticed that the data spikes I was getting got smaller after we had a lot of rain so I checked the mast earth and found the earth wire had become disconnected. So I reconnected it. The mast is all metal - being galvanised iron at the bottom and copper at the top - and I think the wet grass and ground around the base may have been conducting static electricity away.

It seems that earthing the screen of the wind sensor cable was enough and it's not necessary to earth the tx battery negative or connect it to the screen.
You do not have the required permissions to view the files attached to this post.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.

Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Temperature data spikes revisited

Postby Gina » Wed Sep 29, 2010 3:53 pm

AAAARRRRGGGGHHH!!!

First console with old Athlon XP laptop
24hrs-Temperatureb0.png

New console on AMD 64X2 desktop
24hrs-Temperatureb1.png
You do not have the required permissions to view the files attached to this post.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.

User avatar
nking
Posts: 804
Joined: Thu Dec 17, 2009 2:03 pm
Weather Station: WH1081
Operating System: Windows 10
Location: Hurstpierpoint, West Sussex, UK
Contact:

Re: Temperature data spikes revisited

Postby nking » Wed Sep 29, 2010 5:59 pm

Hi Gina, Have you changed the transmitter for the new one?

Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Temperature data spikes revisited

Postby Gina » Wed Sep 29, 2010 9:26 pm

nking wrote:Hi Gina, Have you changed the transmitter for the new one?
Yes.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.

User avatar
nking
Posts: 804
Joined: Thu Dec 17, 2009 2:03 pm
Weather Station: WH1081
Operating System: Windows 10
Location: Hurstpierpoint, West Sussex, UK
Contact:

Re: Temperature data spikes revisited

Postby nking » Wed Sep 29, 2010 9:59 pm

An obvious question/answer :roll:

Gina
Posts: 1885
Joined: Sat Feb 21, 2009 12:41 pm
Weather Station: Nothing working ATM - making one
Operating System: OS X, Linux Mint, Win7 & XP
Location: Devon UK

Re: Temperature data spikes revisited

Postby Gina » Thu Sep 30, 2010 5:45 pm

Now you see them... now you don't :roll:
24hrs-Temperaturec0.png
24hrs-Temperaturec1.png

This is a 48 hour temperature plot - an odd spike, then a burst of them, then none...
48hrs-Temperature.png
You do not have the required permissions to view the files attached to this post.
Gina

Sorry, no banner - weather station out of action. Hoping to be up and running with a new home-made one soon.


Return to “Fine Offset/EasyWeather”

Who is online

Users browsing this forum: No registered users and 3 guests