Sandaysoft

Hi
I see your gust is less than the wind speed which is a bit odd. If the temp quirk has happend over a longish period the chances are the wind direction has varied quite a bit otherwise one might suspect some external source of temperature change. Cooling/warming over water - same through shady woodland and if the passing air is quite turbulent there could be some temperature change but 3 or 4 degrees does seem a lot.
Just a thought !
Regards
Alan

Do you have a DECT-phone ?
Especially the base station can be a source of interference (up to 300 meters)

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http://home.xmsnet.nl/hanmir/
http://home.xmsnet.nl/hanmir/radarbox.htm

Goldrush,

You've got me stumped as well.

If the humidity readings are fine and it's just the temperature readings that are fluctuating then it can't be any sort of interference as both would be affected.

Can you tell us just exactly where the transmitter unit is mounted; perhaps close to the house or on a pole?
A picture would be nice if you can post one.

There must be something logically causing this especially as you have swapped over all the units and are still getting the problem.

Mike.

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Retired Radio and Electronics Engineer residing in Cambridgeshire, UK.

As a matter of interest, what happens if you go back a day and re-read the data....is the problem still there?

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Terry Wiltshire
http://www.janter.co.nz/weather/index.htm

Cracked it

3 guesses!!
1. NO
2. NO
3. NO

Turned out to be a faulty wind direction indicator.

God knows why.



As a matter of interest I have attached pics of my set up.. sorry about the quality

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Ello,

Goldrush, I would have never of guessed that a faulty Wind Direction Sensor was causing those erratic temperature readings, I am glad that you have resolved that and that you have kindly posted your discovery on the forum. Any advice on the Fine Offset/Watson/Maplin and all other varieties of the station, is always appreciated by all owners on the foum

I decided to today, implement the following to my weather station setup. (Would of done it sooner but I have been in and out of hospital, over the last two weeks and today was my only opportunity to try it out)

I have found, that by wrapping Tin Foil around the sensor housing, greatly improves the accuracy of the station, without affecting the Transmitters ability to transmit to the Console.
The idea I used was suggested and used by another member of this forum

As many of the members of the forum will have read, I and many other owners of this such station and the La-Crosse Stations, have suffered from Over the Top Temperatures and Odd sensor readouts, mostly due to the poor design of the Transmitter/Sensor housing. I have of course, tried the Plant Pot and Plant Tray Sensor housing, which I still use today, but as many owners will agree, it can be quite difficult to place the various sensors and transmitter within reach of each other, while trying to find the best place to put them.

So many of us end up with a Transmitter Housing that is, inadvertently affected by the sun beaming down on it, or solar heating or whatever else. But I can strongly recommend the sensor housing ideas and the use of tin foil wrapped around the sensor housing.

Best Regards to all on the forum

Jason - WWS

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Jason Duncombe
La-Crosse WS2300 (Wired & Serial) - Cumulus V1.9.3
Check out the Weather Blog

Following on from my prevos post.
I have now discovered on the bench that the wind direction sensor had an intermiient "North" output (we only get a Northerly wind once in a blue moon).
Although North often gave no wind direction reading on the console, Cumulus always interpreted it "correctly" as North, giving the correct wind readings. (I rarely look at the console)

Maybe that somehow caused the erattic temperature readings, although they did occur at any wind directioni,

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I have the same problem with my tempeture. It started this morning, check out my site;

http://www.khbfk.se/vader/skattkarr/trends.htm

Just the temp thats wrong

So you say it is the wind direction that is wrong ? Just to buy a new one or can I fix it ?

Goldrush, how did you prove it was the anemometer ?

Have you found an electronic / mechanical failure, or could be still be either a 'damp', or unsheilded cable problem ?

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......................Imagine, what you will KNOW tomorrow !

Hi mynameis.
Your temeprature graph, although similar does not look so extreme as mine did.
Although I think unlikely, It may of course be the same problem.
1st step I sugest is to unplug the "wind" cable from the transmitter and see if the eratic temperature remains... (obviously you will lose wind info) if it does then it could be the same problem... so then try unplugging the anemometer to see if that is the cause and not the direction sensor (weather vane).

Beteljuice.
I did think it could be cable problem as I have some 50 metres of shielded cat 5 between sensors although correctly grounded.
Steps taken

Basically firstly doing the above which proved it was cable/wind sensors.

Then plugged new anemometer and direction sensor directly into existing transmitter... ok!!

Then replaced original "wind" lead... temp "eratic".

Lowered pole removed anemometer lead from wind direction sensor. still eratic even though the vane was stationary!!!!!!!!!!!!!!!!!
Plugged new wind direction sensor in place of the original (using the original cat 5 cable)... ok
Reconnected anemometer... ok

System working ok
Celbrated with a number of "muckle drams". hic

Switched off external transmitter so as not to interfere with bench tests

Pluuged wind direction sensor into another transmitter on the bench................... temperature eratic!!!!!!!!!!!!!!!!!

Then found that if wind vane pointed North the console intermittentlu gave no wind direction arrow (actually 2 consoles seperatley gave same "no N pointer"), but Cumulus did show North correctly.

A definite problem with the wind direction sensor, but why it should show up as eratic external temperature and nothing else I have absolutely no idea.
Nor why it should have the same eratic effect on temperature no matter what the wind vane direction
As I mentioned. I rarely ever look at the display console, but use Cumulus coupled with the fact that we rarely ever get a North wind meant that I never saw any non indication of North wind.

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Ok, I will try that. Strange that it begins "just like that"...I have had the station for a year now with no problems.

Goldrush,

A faulty wind unit affecting the temperature readings is very strange, not sure how that can happen electronically speaking.

However plugging the various cables in and out could certainly cure the erratic readings; I'm wondering if that was part of the problem.
The telephone type plugs and sockets they use on these units are far from being waterproof.

However I'm glad you've sorted the problem at last.

Mike.

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Retired Radio and Electronics Engineer residing in Cambridgeshire, UK.

Disconnected the windcabel, then the temperture was stady under that period of testing. Likly its the same problem...

I know that very strange things can happen with electronics; having been in that trade for the last 30 years; and it doesn't get any better.

Mike.

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Retired Radio and Electronics Engineer residing in Cambridgeshire, UK.

Hi mynameis. just a point I assume you have changed your transmitter batteries?
It is just possible that the eratic readings are due to batteries and when the "wind" cable is removed, the drain on them is slightly reduced, rectifying the problem.
Suggest you change them before anything else.

In some ways I am ppleased that someone else seems to have similar problems.... I was begining to think it was all the barrels of whisky I consumed trying to figure it out........ bottles did not work:-)

Also interesting that it has occured after some time in operation, 18 months in my case, a year in the other.

If anyone figures out how the wind direction sensor effects teperature reading, I'd certainly be interested to know.

Back to the only thing worthwhile............ consumption of "the water of life"

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