Wind measurement

[charlieblair]

Can anyone advise on where I can get a cheap anenometer (sp?)?. I need something that will either record 2 weeks worth of data or transmit to a remote computer using a mobile. I intend to stick it on the top of an old telegraph pole, so about 5m I guess. Ideally I'd want to measure the following:   average wind speeds (per minute, or less); peak gusts; direction (less important). Obviously it would have to be one of those devices with open cups that can measure wind from any direction. I guess an old mechanical device would be fine, as long as the recording mechanism could be made waterproof.

Are there cheap mass-produced anenometers around? Or is there anywhere worth looking (ebay not coming up with much)? Ideally I'd like to get several to test a few different sites, so a professonal system at several grand isn;t an option. Any suggestions much appreciated.

Ta

Charlie

[wyleu]

Unfortunately you live on the edge of a marketing boundary.

Self contained Weather stations (as sold by navitron) are spectacularly cheap for the information they provide, but data logging is a value add, plus there's all them bloomin' support calls to field. I've one of the navitron ones on the top of my gable and it seems to be holding up in the wind. people have talked of hacking the wireless, which is would be a nice way of getting stuff out. If someone could squirt out RS232 I'd look to bolting it onto the nacent web server thingy I've got bouncing around now.

[chaso]

Just found this site http://www.audon.co.uk/1-wire_weather.html . Might be something that could be usefull mabe Ivan could get hold of these.

[f828]

have you looked at www.windsurvey.co.uk..................

[wyleu]

Perhaps we want to send some sort of statement of intent to these people to allow some scale of the people interested in this sort of measurement. It's obvious there are several groups of a greater and lesser degree of solution out there and I don't doubt they all have their own particular views on how it should all come together but perhaps we can at least help by making our interest known? All the bits seem to be in place but we need a mechanism to allow all these different systems to talk together or we will have nacent warfare at some stage.
I'm quite prepared to put something together but it's difficult to know exactly how to address it and under what banner to proclaim. We really don't want to weasel pee anybody off at this or any other stage, just indicate a possible route that could be developed. It seems to be at one continual chain: the weather forecasters to wind generators to solar water heaters to PV users to meter watchers. All have similar requirements and probably fairly similar data sets. A little talk at this stage could save almost years of back pedalling and rear guard fighting. If we want to build this as a community we have to be able to demonstrate inclusiveness as well as vision.

Any one any ideas for other organisations to approach?

[charlieblair]

Thanks for those two links guys. Both look interesting. Although (typically) it's not a real option having a permanently running PC at the site(s) I'm thinking of.
Wyleu, I'm not 100% sure what you mean; but reckon it def sounds like a good idea to let manufacturers/software people know that there is a big potential market if they sorted out synching the software and the hardware.

[wyleu]

Dont worry CB, it's all a particular beef of mine that this forum allow me to beat the drum for. You shouldn't be needing the PC ultimately but it's kind of required at the moment if you want to play around with this sort of stuff but hopefull we will be able to reduce it to just the bare bones at some time in the future. We are hoping to reduce the PC requirement to just viewing in the end.

[Ex_Sailor]

I'm not sure of the costs, as we bought quite a few of them, but I have used the LogIT from Fisons Scientific.
They didn't need a PC as they could store information for later downloading. I seem to remember that if they ran stand-alone, they ran at 'half speed', only logging the data at a longer time interval. That was the reason we had them, they ran for months on their own, logging stress in ships as sea.
I built our own software, so I think the price was quite reasonable for the hardware.

I'm sure a group buy wouldn't be too outlandish.

HTH

Colin

[KenB]

Hi,

This company offers cheap anemometers starting at about £30

http://www.aceselectronics.co.uk/section.php?xSec=50


Regarding eliminating the PC for datalogging and display, have you considered using a Palm PDA?   The use very little power, can be programmed in Visual Basic, and offer RS232 serial capablity.

I recently saw one internet supplier, offering quantities of refurbished 8Mb Palm III with colour LCD for £10 plus VAT!



Ken

[wyleu]

I've been casting lusty glances in the general direction of Palms recently. Mind you this interupts my alleged washing up in a tutu and very definate planing of the painful demise of a couple of the regular posters on this board. I'm sure our Weymouth correspondant is in need of a periodic inspection where his intimate equipment is insulation tested. The regs say this can be done at up to 500 volts; Now we would want that now would we?

[Amaterasu]

Wyleu....
I would not recommend palms.

I had to attend a fire once where someone in a grass skirt was set alight (as a prank) - not a pretty sight.

I suggest you stick with your velour tutu

[Bargeman]

Hello Colin,

I looked around for the LogIT machine you mention. It seems that Fisons were taken over by Rhone Poulenc in the mid 1990's. What became of their logging device is a bit of a mistery. I cannot locate an up-to-date reference for it.

regards

[charlieblair]

Hi all,

I've given up on logging remotely - seems too complicated - and have now bought an anemometer on ebay. It's now up and seems to be transmitting info happily down 200+m of bellwire. If anyone is thinking of getting one I can report that the hardware and software are both spectacularly simple - literally jab the thing on a pole and plug the connector into the back of your computer. My inspeed one comes with downloadable software that gives current/max/min/average readout as well as logging each variable at intervals down to a minute.

A few questions:

Does anyone know if  Excel sheets have any limit on the number of lines? The file it records to seems to take up very little disk space; but if I find I can't fit more than a few days on a spreadsheet then I'll increase the interval.

The data logs both an average (over the interval - currently a minute) and an instantaneous reading. I've played around in excel with frequency distributions, to eventually combine with the power curves on the navitron site, but I'm still trying to work out whether the minute-average or the instantaneous figure would be a better number to use. Any suggestions? (I'm inclined to go with instantaneous, as the second by second variability seems surprisingly high).

ta

 C

[wyleu]

For data logging you really need a database, Excel is really an analysis tool, the size of the spreadsheet you create is not really limited but don't expect rippling performance on big sheets. To give a sense of scale, my logging system has collected over 300,000 readings since December the 20th and that's just 5 sensors.

[charlieblair]

The data logs directly into a csv file, which can grow as big as it wants. All I really want the excel sheet to do is give me a frequency distribution of the different wind speeds. From that I can get a valid capacity factor and do some decent cashflow sums. I can't see why excel shouldn't be able to cope with large datasets; but it wouldn't surprise me if there was some bug that stops it doing so.