Topic: Vantage PRO 2 not measuring wind direction and over measuring rain fall

[MCDA]

it should change with temperature and humidity

from the Davis documentation only wind speed and temperature are used to calculate windspeed.

http://www.davisnet.com/product_documents/weather/app_notes/AN_28-derived-weather-variables.pdf

Does that mean it is sensing the windspeed somehow, but not displaying it?

[MCDA]

LMAO Your not going to believe this!  All of a sudden today at about 10:30am the wind speed started working again!!  It corresponds to a jump in solar radiation.

09:40    1.5 °C    -               -1.4°C    1016.5hPa    Calm         0.0km/h    81%    0.0mm / 0.0mm total    169.00 watts/m^2    
09:50    2.2 °C    -            -0.9°C    1016.5hPa    Calm         0.0km/h    80%    0.0mm / 0.0mm total    464.00 watts/m^2    
10:00    2.7 °C    -            -0.9°C    1016.5hPa    Calm         0.0km/h    77%    0.0mm / 0.0mm total    505.00 watts/m^2    
10:10    2.7 °C    -            -0.9°C    1016.5hPa    Calm         0.0km/h    77%    0.0mm / 0.0mm total    553.00 watts/m^2    
10:20    2.2 °C    -            -1.7°C    1016.5hPa    Calm         1.6km/h    75%    0.0mm / 0.0mm total    377.00 watts/m^2    
10:30    2.6 °C    -            -1.2°C    1016.5hPa    North    1.6km/h    22.5km/h    76%    0.0mm / 0.0mm total    488.00 watts/m^2    
10:40    2.9 °C    -0.1 °C    -1.4°C    1016.5hPa    North    11.3km/h    24.1km/h    73%    0.0mm / 0.0mm total    558.00 watts/m^2    
10:50    3.1 °C    0.1 °C    -1.6°C    1016.5hPa    North    11.3km/h    22.5km/h    71%    0.0mm / 0.0mm total    446.00 watts/m^2    
11:00    2.7 °C    -1.2 °C    -2.4°C    1016.5hPa    North    16.1km/h    29.0km/h    69%    0.0mm / 0.0mm total    273.00 watts/m^2    
11:10    2.7 °C    -1.3 °C    -2.4°C    1016.5hPa    North    16.1km/h    27.4km/h    69%    0.0mm / 0.0mm total    189.00 watts/m^2    
11:20    2.6 °C    -1.2 °C    -2.3°C    1016.5hPa    North    14.5km/h    30.6km/h    70%    0.0mm / 0.0mm total    133.00 watts/m^2    
11:30    2.4 °C    -1.4 °C    -2.7°C    1016.5hPa    North    14.5km/h    24.1km/h    69%    0.0mm / 0.0mm total    107.00 watts/m^2    

The gates to access the station are all locked and NOONE has been near it!

[belfryboy]

Does that mean it is sensing the windspeed somehow, but not displaying it?

That seems unlikely. To be certain, (I couldn't tell from your posting of data, it had no column titles) are you seeing wind chill, or is the third column showing dew point? I really can't think of anyway that the console or weatherlink would calculate wind chill without a 10 minute average wind speed.

[MCDA]

That seems unlikely. To be certain, (I couldn't tell from your posting of data, it had no column titles) are you seeing wind chill, or is the third column showing dew point? I really can't think of anyway that the console or weatherlink would calculate wind chill without a 10 minute average wind speed.

I dont use Weatherlink, I'm using a Raspberry Pi running WeeWX to archive the data and upload to Wunderground every 10mins.  The Pi is connected via Davis USB data logger to the console.

[dalecoy]

Does that mean it is sensing the windspeed somehow, but not displaying it?

That seems unlikely. To be certain, (I couldn't tell from your posting of data, it had no column titles) are you seeing wind chill, or is the third column showing dew point? I really can't think of anyway that the console or weatherlink would calculate wind chill without a 10 minute average wind speed.

Where is it not displaying it?

On my normally-operating VP2, if there is no wind, the anemometer is not rotating.  There are no pulses from the anemometer reed switch.  The ISS sends that information (no pulses).  Therefore, the console displays the wind speed as zero.  Software sees the same thing.  After 10 minutes of no wind, the 10 minute average wind speed is zero.

The console calculates wind chill (and can display it).  Calm = No Wind = Zero wind speed and is a completely valid weather condition.  Therefore, the console calculates wind chill.  The console doesn't care whether the anemometer is stuck, or broken, or not reporting, or whatever.

KDDA, what is happening differently from that (when your anemometer "isn't working")?

The formula for wind chill depends on temperature and wind speed, and is quite happy to work with zero as the wind speed.  And in fact:

"any place where the result yields a wind chill temperature greater than the air
temperature, the wind chill is set equal to the air temperature. This always occurs at wind speeds of 0
mph or temperatures above 76
F. This also occurs at lower wind speeds with temperatures between 0
F
and 76
F."

What am I missing here?  

[MCDA]

I dont know, I've given up with this thing.  Giving me a sore head   

Just decides to work when it feels like it.  Fingers crossed the wind direction sensor comes on-line too.

[dalecoy]

OK, yeah, I'm tired of it, too.  Thanks for the entertainment.

[dalecoy]

...  Fingers crossed the wind direction sensor comes on-line too.

Just checking - do you understand that the wind direction will not be reported (by the console) if the wind speed is zero?

[MCDA]

Just checking - do you understand that the wind direction will not be reported (by the console) if the wind speed is zero?

Yes I understand that.  We are currently experiencing strong winds and the cups are spinning freely.

I'm sorry for snapping at you dalecoy, I know your only trying to help.  I'm just confused and very frustrated.  I like things to be logical and problem/solution, but this is driving me crazy!  The station has been recording calm with no wind speed for this past few days, even in the middle of a storm.  I've tested all the wiring which is fine, I haven't touched it for a few days and no-one else has been near it, yet all of a sudden it starts recording the wind speed shortly after 10:20 this morning!

[dalecoy]

Yes, of course.

A.  You have speculated that the problem might be related to low voltage.
B.  The Supercap is disconnected, so that's not a source.
C.  The sun is shining brightly, therefore supply voltage is higher.  And it's running off of the solar cell. 

Although I have expressed doubts, that set of facts supports the "related to low voltage" theory.

=============

I had originally assumed that you were reporting measurements as displayed on the console.  I'm now guessing that's not correct, and you are reporting what you read from the console using your software.  Is that correct?

And describing the columns of data that you are inserting, would perhaps be helpful.

[MCDA]

I had originally assumed that you were reporting measurements as displayed on the console.  I'm now guessing that's not correct, and you are reporting what you read from the console using your software.  Is that correct?

And describing the columns of data that you are inserting, would perhaps be helpful.

Sorry, the tables of data are from the station page on Wunderground.  But the console is displaying the same information.  I have just realised that while the wind speed was being recorded as calm the site did not display a wind chill column and the column I mistakenly thought was wind chill was in fact dew point.  Now that the wind speed is being recorded again (on today's results) I have two columns one for wind chill and another for dew point.  So that clears up that mystery, I was reading it wrong!

Both wind speed and rain gauge have started to work correctly.  The only sensor not currently working is the wind direction.  I do believe that the problem is power related and due to the supercap corrosion.  I guess I need to either prove or disapprove that theory by replacing the cap.

[MCDA]

Again after no-one touching the station or the console I have just recorded a movement on wind vane!!  I run outside and it is pretty calm but there is a slight easterly so its almost right!

21:00    0.4 °C    -    -3.2°C    1011.7hPa    North    1.6km/h    6.4km/h    77%    0.0mm / 0.0mm total    0.00 watts/m^2    
21:10    0.5 °C    -    -3.1°C    1011.7hPa    North    1.6km/h    6.4km/h    77%    0.0mm / 0.0mm total    0.00 watts/m^2    
21:20    0.5 °C    -    -3.1°C    1011.7hPa    ENE            1.6km/h    6.4km/h    77%    0.0mm / 0.0mm total    0.00 watts/m^2    
21:30    0.4 °C    -    -3.1°C    1011.7hPa    Calm         4.8km/h                 77%    0.0mm / 0.0mm total    0.00 watts/m^2    
21:40    0.5 °C    -    -3.1°C    1011.7hPa    ENE           1.6km/h    6.4km/h    77%    0.0mm / 0.0mm total    0.00 watts/m^2    

Can anyone explain to me what is going on?  Or will I just make a toast to the fairies

[MCDA]

Well my new Super Cap came today.  Its a 33F one so not sure if its going to work, worth a try though!  I've soldered it in and had to do a bit of leg bending without putting strain on where the leg enters the Cap.  Its a LOT fatter than the old one but the cover seems to fit, so happy days!

If it lasts over night, without its backup battery, Ill be a very happy man!

[KM4FFB]

Ive been reviving a lot of old threads lately.

Any updated report of things improving, or worsening?