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replacing my weather station- Davis Pro??

Posted: Sat 31 Mar 2012 8:48 am
by ilan72
when i bought my LaCrosse weather station, more than two years ago, i had no clue about what was good and what was better. as a weather amateur and statistics fan i can say,now, that LaCrosse was a total flop....it didn't record the higher wind gusts,rain amount under 0.5 mm is not recorded, the temp in summertime was about two degrees higher than it should be due to the solar radiation, i lost signal for hours and the fact that the station records only 175 sets of data made me lost many hours of data when i had to shout down my pc. in addition, every break in elecricity led to odd data.. Cumulus didn't like LaCrosse so much....

so, it is time to replace my weather station and begin all statistics from scratch. And here i need your help for deciding.

a weather station which will suit my needs must include:

1) wind- records wind gusts as frequent as possible so i won't lose the main gusts.

2) temp - must be accurate and not affected by solar radiation

3) rain- get the real total rain amount and not affected by the wind, rain will not not lost because of wind. 0.01 or 0.02 mm will be recorded too.

4) sunshine- i want to record the total hours of sunshine everyday. what do i need for that? is there a possibility to have the percentage of sunshine ( out of daylight hours) everyday?

5) metric- i need the data to be metric. as i live outside the USA i know that they don't tend to use metric data. Do i need adapters?
6) compatible with comulus- i want the data to be seen on my pc through comulus. do i need anything in addition for that?

of course, humidity, pressure etc are recorded too.....

i have a house with a garden. i need the station to be wireless. the distance between the garden to the desk where my console and pc are is about 15m.
i am ready to pay more moneythan i paid for LaCrosse.

i will be more than grateful for any comment! thanks in advance!!

Re: replacing my weather station- Davis Pro??

Posted: Sat 31 Mar 2012 3:31 pm
by Johnny25
The Davis Pro will do all the things you want.

I currently use the Vantage Vue which is an excellent product, but doesn't have the sensors for the sun etc.

Like most things, you pay more for more quality/reliability.

Re: replacing my weather station- Davis Pro??

Posted: Sat 31 Mar 2012 4:21 pm
by archae86
ilan72 wrote:2) temp - must be accurate and not affected by solar radiation
While the VP2 has pretty good radiation shielding, it is still subject to the problems of your site. If you place it over concrete baking in the sun, it will report the air temperature there, which will be higher than elsewhere--even with the fan aspiration option.
3) rain- get the real total rain amount and not affected by the wind, rain will not not lost because of wind. 0.01 or 0.02 mm will be recorded too.
Wind modification of rain is rather more a siting problem than a problem of the instrument itself.

.01 mm of rain is very, very little. As with most remote-reading gauges, Davis uses a tipping bucket scheme. On my old, simple, LaCrosse, with US units, a single tip was 0.04 inch of rain. On my U.S. model Davis, it is 0.01 inch. I think the metric model is very similar in amount, probably 0.2mm. I don't think anyone is selling a tipping-beam meter which will report 0.01 mm. That would imply either a very wide bucket opening, or a very small tipping beam spoon, or both. And it would mean extremely high tipping rates at even moderate rain rate. Campbell boasts of the fine resolution of this product, which has a ten-inch opening, but nevertheless only manages 0.1 mm increments.

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4) sunshine- i want to record the total hours of sunshine everyday. what do i need for that? is there a possibility to have the percentage of sunshine ( out of daylight hours) everyday?
For this, you first need a solar sensor, which Davis will sell you as an add-on to a base model VP2, or includes as part of one or more of the upgraded models. If you have that, Cumulus software will estimate hours (and tenths) of sunshine, using a model for maximum possible watts per square meter for your location and date/time, and a user-settable percentage of that to define as "sun out".

As with so many other things, site matters crucially here. You may find it very difficult to provide horizon-to-horizon unobstructed view of the sun on all days of the year. You may find use of one of the many web sites which will provided azimuth of sunrise and sunset by date for a location useful in understanding the particular range of horizon required at your site. Of course, raising the sensor up a pole may help if your obstructions are low, though in the Davis design, the sensor is co-located with the rain gauge to within a very short cable length, though it may well work to use a simple extension cable suitable for outdoors work with attention to sealing the joint. Rain measured higher than the standard height above ground may differ, though I believe this is a matter of air currents so highly variable with site.
i have a house with a garden. i need the station to be wireless. the distance between the garden to the desk where my console and pc are is about 15m.
Most VP2 users seem to be extremely happy with the transmission reliability of the system, especially in comparison to other home wireless products. Range, reliability, and error-checking all seem rather dramatically superior to the usual run of consumer remote rain gauges, remote thermometers, driveway alarms, mailbox alarms... I actually had a problem in setting up my VP2 which turned out to be that I had left it on the default channel and was getting a mix of signals from my own new station and that of a neighbor about 500 feet away. A change of channel fixed that. My only other repeating problem seems to have been caused by interference picked up from a cell phone charger operating about two feet from one of my two receivers (an Envoy). I just moved the cell phone charging location and all has seemed well since.
i am ready to pay more moneythan i paid for LaCrosse.
That is likely to be necessary. Davis products cost much more in many overseas locations than with available "private message" discounts in the US. But if you procure a US model it may not comply with radio frequency allocations in your home jurisdiction, and a metric adapter might be required. Service may also be compromised in this case.

Re: replacing my weather station- Davis Pro??

Posted: Sun 01 Apr 2012 12:09 am
by PaulMy
4) sunshine- i want to record the total hours of sunshine everyday. what do i need for that? is there a possibility to have the percentage of sunshine ( out of daylight hours) everyday?
The B-L Sunrecorder is a stand alone unit but is supported by Cumulus. http://www.komokaweather.com/weather/su ... ay_v1.html

Paul

Re: replacing my weather station- Davis Pro??

Posted: Sun 01 Apr 2012 4:27 pm
by ilan72
PaulMy wrote:
4) sunshine- i want to record the total hours of sunshine everyday. what do i need for that? is there a possibility to have the percentage of sunshine ( out of daylight hours) everyday?
The B-L Sunrecorder is a stand alone unit but is supported by Cumulus. http://www.komokaweather.com/weather/su ... ay_v1.html

Paul
thank you for this useful message. however, i don't find the price of it. wqell. i found now. it is sadly too expensive for me.....

Re: replacing my weather station- Davis Pro??

Posted: Sun 01 Apr 2012 4:29 pm
by ilan72
Johnny25 wrote:The Davis Pro will do all the things you want.

I currently use the Vantage Vue which is an excellent product, but doesn't have the sensors for the sun etc.

Like most things, you pay more for more quality/reliability.

thanks Johnny. i thought of buying the Vantage Vue and forget the sunshine measurments but i see that there are more parameters which make vantage pro better than vantage vue.

thank you archae for the detailed and very useful info. i appreciate that very much! i read so many reviews and comments about vantage pro. some of them don't really justify the price ( because you need to add the weatherlink software). Isn't there a metric version of vantage pro as in vantage vue? i hate the word 'adapter'......

Re: replacing my weather station- Davis Pro??

Posted: Sun 01 Apr 2012 7:31 pm
by PaulMy
Isn't there a metric version of vantage pro as in vantage vue?
The Davis VP2 comes with metric sleeve that many of us use. The sleeve is a simple exchange so that each tip of the bucket is 0.2mm, which is approximate the same as 0.01 inch.
i read so many reviews and comments about vantage pro. some of them don't really justify the price ( because you need to add the weatherlink software).
Agreed, the Davis VP2 is at the higher end in cost, especially if you compare it priced with the Weatherlink data logger included, to other stations that also have the logger. Does it justify the price? Well that depends on each individual on their personal interest, expectation, and ability. The Davis is very good - accurate and frequent data, several options, solid built and reliable, great wireless reception, and for me the price is justified by its quality and simplicity to maintain and operate - going onto 4 years with a battery replacement this winter the only maintenance. I do recognize that the cost of the Davis can be much higher in some countries compared to the USA and Canada.

All the best in your decision deliberation...

Paul