Accuracy of Davis weather station “rainfall” measured?

MX7

Member
Location
cotswolds
As above , do any of you think the Davis , over reads or under reads rainfall against any other rain gauge you use.?
 

An Gof

Member
Location
Cornwall
As above , do any of you think the Davis , over reads or under reads rainfall against any other rain gauge you use.?
I have a dAvis Vantage View of my own and find it quite accurate and in line with other recorders. However I also have on the farm A Davis Vantage Pro put in place by another organisation. I have been convinced that it seriously under records rainfall.
AHDB have a similar machine on the local monitor farm and I know, after speaking with the farmer, that they have had to make quite a few adjustments to it to get it reading correctly.
 
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Lorem

Member
Media
An industrial-grade weather station engineered to handle the harshest environments and deliver data with scientific precision, year after year. The Vantage Pro2 and Vantage Pro2 Plus offer the professional weather observer:

Inside & Outside Temperature/Inside & Outside Humidity/Dew Point/Wind Speed & Direction/Wind Chill & Heat Index/Barometric Pressure/Rainfall & Rain Rate/Forecast/Moon Phase/UV*/Solar Radiation*/THSW Index*



Tech Specs


Transmission up to 1,000 ft (300 m).
Frequency-hopping, spread spectrum radio provides 3x the transmission distance of the competition with improved reception through multiple walls and greater immunity from RF interference.

Choose wireless or cabled.
Wireless stations send data effortlessly to the console via the solar-powered transmitter. Cabled stations offer economical installations where lightning risk is minimal.

Solar-powered.
Energized by the sun during the day, by the onboard supercapacitor at night. A lithium battery provides backup when needed.



Operating Temperature
-40° to +150°F (-40° to +65°C)

Non-operating Temperature
-40° to +158°F (-40° to +70°C)

Current Draw
0.14 mA (average), 30 mA (peak) at 4 to 6 VDC

Solar Power Panel
0.5 Watts (sensor transmitter), plus 0.75 Watts (Fan-Aspirated)

Battery (ISS SIM /Fan-Aspirated)
CR-123 3-Volt Lithium cell / 2 - 1.2 Volt NiMH C-cells

Battery Life (3-Volt Lithium cell)
8 months without sunlight - greater than 2 years depending on solar charging

Battery Life (NiMH C-cells, Fan-Aspirated)
Up to 2 years

Fan Aspiration Rate (Fan-Aspirated only)
Intake Flow Rate, full sun: 190 feet/min. (0.9 m/s)

Intake Flow Rate, battery only: 80 feet/min. (0.4 m/s)

Sensor Chamber Flow Rate, full sun: 500 feet/min. (2.5 m/s)

Sensor Chamber Flow Rate, battery only: 180 feet/min. (0.9 m/s)

Sensor Connectors
Modular RJ-11

Cable Type
4-conductor, 26 AWG

Cable Length, Anemometer
40 feet (12 m) (included); 240 feet (73 m) (maximum recommended)
 

DartmoorEwe

Member
Livestock Farmer
Location
Yelverton, UK
We recently got a Davis (it was my birthday) and the rain recording is somewhat lower than our previous Youshiko. Comparing with our analogue rain gauge and with other local stations I preferred the data from the Youshiko but Davis' response when we queried how to calibrate the rain gauge implied that they are the best and therefore their rain gauge is right. The problem therefore persists and my attention went elsewhere but I don't trust my rain data.

For such an expensive "industrial and scientific" product I felt their after sales assistance was unhelpful and unscientific.
 

farmerm

Member
Location
Shropshire
I am not sure of the calibration for the Davis rain gauges, someone will known.. most have an adjustment screw somewhere.. for the type of RG I use 50ml trickled gently in to the top should result in ten tips ie 10mm being recorded. I think the Davis measures with a 0.1mm resolution but given the rainfall just 100m away could easily be 2mm more or 2mm less does sub mm accuracy really tell you anything meaningful? Make sure the RG is level as this can make a big difference. Spiders webs have been known to foul mechanisms and cause under measurement, dirt build up on the spoon or in the funnel also affect accuracy.
 

An Gof

Member
Location
Cornwall
An industrial-grade weather station engineered to handle the harshest environments and deliver data with scientific precision, year after year. The Vantage Pro2 and Vantage Pro2 Plus offer the professional weather observer:

Inside & Outside Temperature/Inside & Outside Humidity/Dew Point/Wind Speed & Direction/Wind Chill & Heat Index/Barometric Pressure/Rainfall & Rain Rate/Forecast/Moon Phase/UV*/Solar Radiation*/THSW Index*



Tech Specs


Transmission up to 1,000 ft (300 m).
Frequency-hopping, spread spectrum radio provides 3x the transmission distance of the competition with improved reception through multiple walls and greater immunity from RF interference.

Choose wireless or cabled.
Wireless stations send data effortlessly to the console via the solar-powered transmitter. Cabled stations offer economical installations where lightning risk is minimal.

Solar-powered.
Energized by the sun during the day, by the onboard supercapacitor at night. A lithium battery provides backup when needed.



Operating Temperature
-40° to +150°F (-40° to +65°C)

Non-operating Temperature
-40° to +158°F (-40° to +70°C)

Current Draw
0.14 mA (average), 30 mA (peak) at 4 to 6 VDC

Solar Power Panel
0.5 Watts (sensor transmitter), plus 0.75 Watts (Fan-Aspirated)

Battery (ISS SIM /Fan-Aspirated)
CR-123 3-Volt Lithium cell / 2 - 1.2 Volt NiMH C-cells

Battery Life (3-Volt Lithium cell)
8 months without sunlight - greater than 2 years depending on solar charging

Battery Life (NiMH C-cells, Fan-Aspirated)
Up to 2 years

Fan Aspiration Rate (Fan-Aspirated only)
Intake Flow Rate, full sun: 190 feet/min. (0.9 m/s)

Intake Flow Rate, battery only: 80 feet/min. (0.4 m/s)

Sensor Chamber Flow Rate, full sun: 500 feet/min. (2.5 m/s)

Sensor Chamber Flow Rate, battery only: 180 feet/min. (0.9 m/s)

Sensor Connectors
Modular RJ-11

Cable Type
4-conductor, 26 AWG

Cable Length, Anemometer
40 feet (12 m) (included); 240 feet (73 m) (maximum recommended)

Good advert ;) I have a Vantage Pro here (installed and owned by a third party) and i do not believe the rainfall recording to be correct. As i previously posted another farmer nearby also has one (put in place by AHDB) and he has had to have it adjusted as it was not reading correctly.
Yes they are good instruments but like all things not infallible. I have more faith in my personal Vantage Due than the Vantage Pro
 

farmerm

Member
Location
Shropshire

fermerboy

Member
Location
Banffshire
I'd need to read up the manual again, its been a while since I set mine up.

Is it set for the european gauge in the settings? The USA ones have a different tipping cup inside, USA one tip is 5.4mm of water, EU is 4.3ml I think, so the console needs to know this.
Spider or dead insects blocking things up? Or jamming the cup.
Is it correctly situated? Its tricky getting a spot that isn't too sheltered or too windy, at the right hight as well.

It can be calibrated but its fiddly I think.

Some good info here.
https://www.manula.com/manuals/pws/davis-kb/1/en/topic/rain-gauge-faults
 

DartmoorEwe

Member
Livestock Farmer
Location
Yelverton, UK
Thanks fb, Davis have now sent some useful feedback. The outside box is not talking to the indoor box all the time. This means there's gaps in the data. They suggested to try line of sight so the internal box is now sat on a dining chair by the window facing the outside box but this has not solved the problem. The next thing we've been told to try is to change the channel - when I get around to it I'll check fb's link to work out how to do that and see if it works.
 

Brisel

Member
Arable Farmer
Location
North Yorkshire
I have a dAvis Vantage View of my own and find it quite accurate and in line with other recorders. However I also have on the farm A Davis Vantage Pro put in place by another organisation. I have been convinced that it seriously under records rainfall.
AHDB have a similar machine on the local monitor farm and I know, after speaking with the farmer, that they have had to make quite a few adjustments to it to get it reading correctly.
I also host a Davis Vantage Pro for what might be the same outside organisation as you (I host the Croft northern NIAB trials). It under-reads by 50% compared to a manual one 200 yards away. The firm from Beds who manage these for KisanHub didn't out it up level nor put any stay wires in to keep it level. They weren't very keen on coming up to fix it either. There's a spirit level under the main rain gauge which needs to be level. I'd suggest a good coating of fly spray in the spring to keep spiders away from the tipping spoons.

Agrii have a station 10 feet away from the Davis whose name I can't see & it is much more accurate. Far better set up too. Luckily I can see their data too.
 

An Gof

Member
Location
Cornwall
I also host a Davis Vantage Pro for what might be the same outside organisation as you (I host the Croft northern NIAB trials). It under-reads by 50% compared to a manual one 200 yards away. The firm from Beds who manage these for KisanHub didn't out it up level nor put any stay wires in to keep it level. They weren't very keen on coming up to fix it either. There's a spirit level under the main rain gauge which needs to be level. I'd suggest a good coating of fly spray in the spring to keep spiders away from the tipping spoons.

Agrii have a station 10 feet away from the Davis whose name I can't see & it is much more accurate. Far better set up too. Luckily I can see their data too.
Bit late to the party and just seen this. Yes it will be for the same organisation. But the relationship has ended between Kisan and NIAB Tag
I’m hosting the weather station and now can’t get any of the data 😡
Mind you Kisan Hub failed to impress me right from the start 😡
 

Brisel

Member
Arable Farmer
Location
North Yorkshire
Bit late to the party and just seen this. Yes it will be for the same organisation. But the relationship has ended between Kisan and NIAB Tag
I’m hosting the weather station and now can’t get any of the data 😡
Mind you Kisan Hub failed to impress me right from the start 😡
Can you not find your location on the Davis website? Is it no longer transmitting? Your station will have a KH... number. I can read mine using the WeatherLink app on my phone.
 

An Gof

Member
Location
Cornwall
Can you not find your location on the Davis website? Is it no longer transmitting? Your station will have a KH... number. I can read mine using the WeatherLink app on my phone.
They never seemed to put it on the WeatherLink app which annoyed me. Best I could describe them as is a shower 😡
 

Early moves to target wild oats

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Growers and agronomists now face the dilemma of an early application to remove competition from emerged wild oats, or holding off to allow more weeds to germinate.

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Miss Wood urges...
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