Recommended equipment

For discussion of any observing equipment, from Stevenson Screens and manual instruments to electronic weather stations

Recommended equipment

Postby greg_gruner » 2012 Feb 16, 21:33

I am intending to buy an electronic weather station, and I was wondering if any COL members could give me some advice/recommendations. The Davis Vantage Pro2 seems to be the top of the range, a bit pricey but can be had for under £400 if you search. If I do spend that amount of money, though, I want to be sure I am getting something accurate and reliable.
Greg Gruner
Farnborough, Hampshire
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Posts: 224
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Re: Recommended equipment

Postby Stephen Burt » 2012 Feb 17, 12:39

I've had a Davis AWS since February 1993, and a Vantage Pro2 since March 2008. My first unit lasted 17 years with very few problems.

I prepared a detailed comparison of a Davis VP2 alongside standard instruments for the COL AGM in 2009, the full report is available online here:

http://www.weatherstations.co.uk/Prodat ... 20AWS%20(c)%20Stephen%20Burt%202009.pdf

Hope you find it useful. (I also have a book coming shortly which goes into much more detail on choosing and siting an AWS.) There are cheaper models, but they lack features and are less robust.

I would be wary of going with the cheapest supplier, though; service and ongoing support are very important too, and some of the bottom-end suppliers are very poor in this regard. For a piece of kit that should last 10-15 years, and will need occasional spares etc, a reliable and knowlegeable supplier with good links to Davis Instruments technical team is vital. Personally I'd recommend John Dann at Prodata, and I know many other COL members are also happy to do so.

SB
-----
Stratfield Mortimer, Berkshire - central southern England
51.4°N, 1.0°W, 60 m AMSL, station grade A - AAAA47R
Records commenced here 1987 - local records available back to 1862
The Weather Observer's Handbook: www.measuringtheweather.com
Stephen Burt
 
Posts: 247
Joined: 2011 Dec 02, 19:36
Location: Stratfield Mortimer, Berkshire; a well-exposed rural site, 10 km SW of Reading

Re: Recommended equipment

Postby greg_gruner » 2012 Feb 18, 19:17

Thanks, Stephen, for that comprehensive reply.
I will go for a Davis VP2, though I need to save up first! I'm just about to move to Paignton in Devon, and to a house with a garden, so I have the opportunity to site an AWS properly. And I look forward to your book...

Greg
Greg Gruner
Farnborough, Hampshire
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Re: Recommended equipment

Postby Darren Rogers » 2012 Feb 19, 21:11

I was going to add that in many ways the cost of the AWS should be balanced with where and how it will be sited - if as you suggest it will be in a garden and I then presume fairly open in exposure then go the full hog and get the VPro2 - you won't be disappointed, but do get the data logger and Weatherlink software as well.

However, what you might then want to try and acquire as well is a standard rain gauge.

One thing that always narks me and just makes me angry is when you see a VPro2 (or any AWS for that matter) mounted at roof height on the gable end of a house - i've seen it so many times and just scream out WHY?

Are they doing it just to get higher windspeed readings because if they are they are totally discrediting any temp and rainfall readings.

The one that I have done, steadily and to be honest with a liitle bit of luck and help and also saving up for is that once I had the VPro2 up and running was to add standard equipment to it, so X'mas and birthday presents for years to come could be a grass thermom', 30cm + 1m soil thermoms', rain gauge.

the only other bit of advice to give as well would be to make sure that at 0900 hrs each a.m. you 'Go out and do the weather'. Record visibility, cloud cover and type, wind direction, ground conditions, etc - If there was 4" of snow on the ground you would go out and measure it so get into the habit regardless - ithere is a certain satisfaction to be had by actually going out and recording what it is like and not just looking at a console in your house.
Darren Rogers
Maulds Meaburn
Cumbria (Half way between Shap and Appleby)

http://www.mauldsmeaburnweather.co.uk
Darren Rogers
 
Posts: 145
Joined: 2011 Nov 27, 20:22
Location: Cumbria - half way between Shap and Appleby in the Eden valley

Re: Recommended equipment

Postby Stephen Burt » 2012 Feb 19, 22:38

I'd add just one more comment: while an inexpensive AWS can give reasonable results in a reasonable site (uncertain calibration and robustness of components may be bigger issues), spending a lot of money on a top-of-the-range consumer AWS where the exposure is very limited is unwise, as site effects are likely to mean the readings will reflect the site microclimate rather more than the true conditions in the locality.

Given care in siting instruments, all but the most sheltered locations can produce reasonably satisfactory results, although accurate rainfall and wind readings are the most difficult to get right under such conditions.

SB
-----
Stratfield Mortimer, Berkshire - central southern England
51.4°N, 1.0°W, 60 m AMSL, station grade A - AAAA47R
Records commenced here 1987 - local records available back to 1862
The Weather Observer's Handbook: www.measuringtheweather.com
Stephen Burt
 
Posts: 247
Joined: 2011 Dec 02, 19:36
Location: Stratfield Mortimer, Berkshire; a well-exposed rural site, 10 km SW of Reading

Re: Recommended equipment

Postby greg_gruner » 2012 Feb 25, 19:47

Thanks for all your advice.
I have been recording the weather in one form or another for most of the last 45 years, but not with top quality instrumentation. I absolutely agree that you need to do a manual observation as well.
I believe the exposure of my new garden will be OK for an AWS, with no large trees.
Can I ask whether others using an AWS have all the instruments (rain gauge, thermometer, and anemometer) in the same place, or do you split them up? From what I read online, one can split up the sensors, so that you could have the rain gauge at ground level, the thermometer at 1.5m and the anemometer higher.
Also, can you set up the timing so that the AWS takes reading 09-09 rather than 00-00? As I will travelling for work I won't always be there to take the readings at 0900.
Greg Gruner
Farnborough, Hampshire
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Posts: 224
Joined: 2012 Feb 04, 17:28

Re: Recommended equipment

Postby Darren Rogers » 2012 Feb 26, 14:22

Re 'splitting' the AWS components - you can with some, certainly the Nexus which has x3 separate remote wireless units - the Davis Vpro2 allows you to have the anemometer separate to the rest, which is something that I have done and works well at my site, but you need to buy a separate transmiiter unit and they are at least £150 - so the price goues up.
The Davis whilst the best still has some annoying limitations like Mn-Mn readings and recording 0.2mm and 2.0mm (not 0.2 and 1.0mm) for rain and wet days and the rain gauge will always be on top of the main sensor unit - but it is still the best.
I have had a manual rain gauge for over 18 months now and have found that the davis under records rainfall by something like 7% per year - other sites could be more.

Re 0900-0900 readings - the davis does not do this and I know that the Nexus doesn't as well - can't speak for any others, but there is one way around it and this applies for most systems and that is to use Cumulus software.

Cumulus is excellent and free and it allows you to chose between Mn-Mn or 0900-09 readings - you will find that many sites on the web use this and there is also a dedicated forum for users as well.

But most systems will come with software that allows you to record data at intervals ranging from 1 minute to 1 day - if you set it at 5 min intervals it is a relatively easy job to scroll through a days readings to get a flavour and they will all give you daily min/max readings
Darren Rogers
Maulds Meaburn
Cumbria (Half way between Shap and Appleby)

http://www.mauldsmeaburnweather.co.uk
Darren Rogers
 
Posts: 145
Joined: 2011 Nov 27, 20:22
Location: Cumbria - half way between Shap and Appleby in the Eden valley

Re: Recommended equipment

Postby greg_gruner » 2012 Mar 30, 17:49

I am thinking I may go for a Davis Vantage Vue, to save money. Enquiries with Prodata indicate that the sensors are just as good as the Pro, but are mounted in a single unit and cannot be separated. I am not in a position to mount an anemometer at the required 10m anyway, and my site exposure is not perfect, so I think the Vue will do the job.

One thought did occur to me: I live quite close to the sea, and seagulls can be a nuisance, perching on the shed and in trees, laying droppings on cars, etc. I would not want an AWS to become a perching post, with interference on the anemometer and the danger of the rain gauge becoming blocked by droppings. Maybe placing some spikes on the top to deter perching (as sometimes seen against pigeons in railways stations) may be an idea?

Have any other observers who live near the sea had problems with seagulls?
Greg Gruner
Farnborough, Hampshire
greg_gruner
 
Posts: 224
Joined: 2012 Feb 04, 17:28

Re: Recommended equipment

Postby Darren Rogers » 2012 Apr 05, 20:28

I think that i did see this point covered quite a bit on davis's own e-newsletter (just go onto their site) and some people have come up with some interesting spikey solutions - problem being you don't want to effect the rain captured.

Last winter i had a robin visit my VPro2 every day, sit on the rim and do its business - why was its backside always facing into the rain gauge and not outside?
Darren Rogers
Maulds Meaburn
Cumbria (Half way between Shap and Appleby)

http://www.mauldsmeaburnweather.co.uk
Darren Rogers
 
Posts: 145
Joined: 2011 Nov 27, 20:22
Location: Cumbria - half way between Shap and Appleby in the Eden valley

Re: Recommended equipment

Postby greg_gruner » 2012 Apr 08, 20:19

Thanks, I looked at Davis' newsletters - one person put a model snake on the weather station to deter birds!
I think I will see how it goes, and if necessary I'll use bird spikes round the rim.
Greg Gruner
Farnborough, Hampshire
greg_gruner
 
Posts: 224
Joined: 2012 Feb 04, 17:28


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