2005-12-30

A good case of wind

Finally, at around 09:00 this morning, the wind picked up enough to blow out the snow that was clogging up the impeller in the anemometer and, for the rest of the day so far, I've been getting wind-speed readings. From this experience I'm guessing a cup anemometer is better in such a situation. That's one possible lesson to keep in mind for the future.

File Under: Cup Anemometer, Impeller Anemometer, Snow.

2005-12-28

Too much snow

Last night we had a couple of inches of snow. By the standards of people who get "real" snow this is nothing. However, I did notice one interesting side-effect of all the snow: the impeller that measures the wind-speed on the anemometer is now totally snowed in and I'm no longer getting any wind-speed readings.

An unexpected problem and I doubt there's a simple solution. I guess I'm going to have to wait until a good gust of wind or a thaw (expected Friday) clears it.

File Under: Personal Weather Station, Snow, Anemometer Problems.

More work on the new site

I've been experimenting some more with the data I'm getting from Open3600. Thanks to some shell scripts (written in bash) and gnuplot I've now got some simple graphs up and running. Currently I've just got graphs for today's data and yesterday's data up and running — when time allows I'll see about adding graphs for other periods of time.

So far Open3600 seems to be working well. However, I have noticed a couple of odd problems. In the data for yesterday I had two instances of the relative pressure being recorded as 11111 hPa, which is obviously wrong. Also, for yesterday's data, I had a relative pressure reading that dramatically dropped for a couple of minutes (dropping from 1002.5 hPa down to 983 hPa for two minutes and then rising back to 1002.4). Again, this would appear to be way out. I'll keep an eye on this effect and, if it continues, I'll see about reporting this to the authors of Open3600 on the off chance that it's a software problem.

File Under: Personal Weather Station, WS3600, Open3600, gnuplot.

2005-12-27

Initial work on new site

Now that I've got the software link to Linux sorted out I've been able to get the initial work done on the website that'll hold and display weather data. The URL for the site is wxw.davep.org (note: wXw, not www).

Currently the site just has a front page which shows the latest conditions plus some other general site-framework pages. When I get more time I will be adding pages that show all the current day's values plus a system of looking at historical values.

As I do more work on the site I'll document what I've done here and, of course, the ChangeLog for the site will be kept up-to-date.

File Under: Weather Website.

Now working with Linux

I've finally managed to get the link of the WS3600 working with one of my Linux boxes. Despite an earlier failure open3600 is now working a treat and is currently logging details from the weather station around once every minute.

Now that I'm building up a history of data the next step is to start work on the website that will be used to display the current conditions and all available history.

File Under: Personal Weather Station, WS3600, Open3600, Linux.

2005-12-20

Computer link working — sort of

This morning I had a go at getting the PC link of the WS3600 working and talking to one of my GNU/Linux boxes using Open3600. Sadly, I failed. For reasons I'm not sure about yet it either claimed that it couldn't open the COM port or it just sat there apparently doing nothing.

To be sure that the problem wasn't with the cable I hooked the base station up to my Windows XP box and installed the software supplied with the WS3600. Turns out that it's a copy of Heavy Weather. That ran without any problems.

As a little test I've set Heavy Weather up, along with its publishing software, to publish a little display on my weather website. Note that what you see there is just a placeholder page — a proper site with graphs, feeds, histories and the like will follow at some point.

What I aim to do now is go back and try and figure out why Open3600 wouldn't work; it could be that it's the software that's at fault or it could be my hardware.

File Under: WS3600, Open3600, Heavy Weather, Windows, GNU/Linux.

2005-12-19

Temperature reading problem

I've been watching the temperature reading for the last hour or so and it looks like I can confirm that the high reading I saw yesterday is down to sunlight falling on the thermo/hygro transmitter. Here's the readings I've got so far this morning (comparing my Maplin unit and a local personal station with my WS3600 — note that I'll be updating this as the day goes on).

TimeMaplinGranthamWS3600
10:30 GMT3.8°C4.0°C4.9°C
Sun hits thermo/hygro transmitter
11:12 GMT4.4°C4.7°C7.5°C
11:21 GMT5.0°C5.1°C9.4°C
12:08 GMT5.7°C6.8°C12.2°C
Sun no longer hits thermo/hygro transmitter
12:42 GMT6.0°C7.0°C10.1°C
13:04 GMT6.3°C6.9°C8.8°C
13:32 GMT6.5°C7.1°C8.3°C
14:32 GMT6.0°C6.6°C6.8°C
14:57 GMT5.6°C6.4°C6.1°C
15:50 GMT4.2°C5.9°C4.5°C
16:16 GMT3.7°C5.4°C3.7°C


Given this I really am going to need to try and find a better location (hard to do) or try and sort out some sort of extra screen.

File Under: Personal Weather Station, WS3600, Temperature Problems.

WS3600 installation

As I mentioned a couple of days ago, the personal weather station (a WS3600) is finally installed and up and running.

The first job of the day was to fix the bracket of the installation kit to the wall of the office. Given my lack of DIY skills I was anticipating that this would be one of those jobs that wouldn't go smoothly. I couldn't have been more wrong. It probably took me about ½ an hour to get it marked up and get the holes drilled (using the 10mm masonry drill bit that was supplied with the installation kit). The bracket itself screwed into the wall without any fuss using the provided bolts and wall plugs. The hardest part of the job was all the climbing up and down the ladder.

Once the bracket was on the wall the next step was to fit the wind vane to the top of the pole. I'd anticipated that this would be the easiest job of the day. Again, I was wrong. One of the nuts that came with the weather station had an incomplete thread and so wouldn't screw onto the fixing for the vane. Not being a DIY sort of person nuts and bolts aren't the sort of thing I have kicking around so, at that point, I thought I was stuck and would have to give in and wait until I got the chance to visit a DIY shop. At that point I started to have a look around the office for any old equipment that might have the right kind of nut on it that I could use. Luckily I managed to dig out an old Anglepoise-style lamp and, in one of the joints, I noticed that the mechanism that is used to tighten the joint had a nut of exactly the right size. Even better, the lever that the nut was in (it's used to lock the joint of the lamp in place) turned out to be the perfect tool to tighten all the nuts on the vane fixing.

So, thanks to a bit of junk that I'd not got around to throwing out, a minor disaster was averted.

The next job was to fix the pole to the bracket. This was another job that I'd anticipated would be rather tricky — I'd imagined that being up a ladder, holding the pole and using a spanner would be the sort of job that would require at least three hands. Again, it turned out to be a lot easier than I thought it would be. It took little effort to get the pole into the fixings and to tighten them enough to hold it in place. Next, using the compass that came with the installation kit, I lined the wind vane up with north, checked that the pole was as level as possible, and then fully tightened the bolts.

After that all I needed to do was to install the thermo/hygro transmitter and the rain gauge. I decided to fit the transmitter near the bottom of the pole (looking back this might not have been the best idea — see below) and, after fitting it, I plugged the anemometer into the transmitter and tidied up the cables with plenty of cable ties. Finally, I plugged the rain bucket into the transmitter and tacked its cable down the wall of the office.

Currently I don't have anywhere useful to locate the rain bucket so it's sat on top of a coal bunker that's by the side of my office. This probably isn't the best of locations due to the fact that the office shelters it from the west. When I get more time I intend to find somewhere better for the gauge (this isn't made easy by the fact that there are no flat, exposed surfaces available nearby).

All in all it took about two hours from start to finish, allowing for the odd break and the time taken to find a new nut.



Now for one possible problem: Yesterday, close on to lunchtime, I noticed that the WS3600 and my simple Maplin wireless thermometer disagreed on temperature by about 3°C. I then checked with another personal weather station in my area and noticed that it's temperature value was closer to the one that the Maplin unit was showing. On top of this, the nighttime minimum temperature that I'd recorded more or less agreed with the nighttime minimum for the station over in Grantham. This would suggest that it wasn't an overall problem with temperature readings.

I suspect the reason for this might be that, currently, the temperature gauge for the WS3600 is in a location where sunlight falls on it during the morning (it's on an east-facing wall) — the Maplin thermometer is constantly in the shade and on a north-facing wall. I had wondered if this was going to be a problem but, given that the WS3600's thermometer comes with a shade, I was hoping that it was something I wouldn't need to worry about.

Annoyingly, given where I've got everything installed (the location being dictated by the best place for me to site the anemometer), there isn't a shaded location where I can place the thermometer. I'm going to have to monitor this and see if this problem continues (it's a sunny day again today so the Sun will be falling on the thermometer in the next hour or so). If this is the cause for the temperature difference I'm either going to have to try and find a better location for the thermometer or I'll have to try and put some form of shade around it.



So, what next? First up will be hooking the base station up to one of my computers and seeing how well the computer link works. I've got a choice of either using the supplied software and my Windows box (I've not looked at what the supplied software is yet) or, ideally, some Free Software on one of my GNU/Linux boxes. The current Free Software front-runner looks like Open3600.

Once I've decided on how I'm hooking it up and which software I'm using the next step will be to build a website around the data. I doubt I'll have that working any time before the end of this year.

Other things to consider and/or sort out are:

  • Double check my height above sea-level, work out the pressure difference based on this and program it into the base station. This shouldn't be too hard as I can either check on an OS map or I can check it with my GPS unit.

  • Decide if I want to carry on using the wireless link or if I want to go wired. This will depend on the length of the supplied cable (I've not checked it yet) and if I can easily run it from the transmitter to the base station.

  • Look into hooking up with Weather Underground.


and probably some things I've not thought about yet. Seems like I've got plenty of things to play with over the xmas break.

File Under: Personal Weather Station, WS3600, Installation.

2005-12-17

It's up!

The weather station is finally up! I'll write some more about how it went when I have more time. Sorry about the quality of the picture, the sun has just set so it's getting rather dark out there.





File Under: WS3600, Personal Weather Station.

2005-12-14

Installation kit has arrived

The installation kit that I ordered on Monday arrived this afternoon so I've now got everything I need to get the WS3600 installed and set up. Apart from time — I'll need to find some of that too.

It's quite an impressive kit. Last weekend I had a look around for some sort of TV aerial installation kit (ideally one that didn't come with an actual aerial) but couldn't find anything workable in the local DIY stores. What I did find wasn't very substantial and the prices weren't that far off the cost of the Skyview kit. What also sold me on the Skyview kit, given the price and how it compared with aerial kits, was the fact that it comes with all the bolts, screws, washers, plugs and cable tacks you need to do the job. Even better is the fact that it comes with two masonry drill bits, each the right size for the drilling you need to do (I do have a set of masonry bits but I know at least one of them has a broken tip and you can bet that'd be the one I need).

One really nice touch is that they include a small compass for setting up the wind vane. Not that I needed one, but I'd hate to have purchased all these bits and then found that I couldn't finish the job because I didn't have a way of easily finding north (although I might have to get a move on to stand a chance of getting it right).

One amusing moment: the compass is quite small, almost small enough to be a keyring. It's got a small carabiner attached to it. Also attached is a cardboard tag. On the back of the tag it says:

Carabiner is NOT made for climbing!
I'm glad they said that — I had been thinking about using it and some spare string, rather than a ladder, to get up the side of the office.

File Under: Skyview Installation Kit, WS3600, Personal Weather Station, Stupid Product Warnings.

2005-12-13

The story so far...

It's probably very important that I say this right up front: I don't know an awful lot about the weather, weather recording or the use of personal weather stations. If you're looking for help and advice about this subject on the net and you happened upon this blog please keep this in mind — you probably want to be looking elsewhere for answers to your questions.



It started earlier this year when I got back into observational astronomy. Something I made a point of doing as soon as possible was keeping a written log of my observations. I'm still working on the form and content of my logs (both the paper-based and the web-based versions) and, where possible, I try and look for useful information that can be added to them to place them in a useful context.

One thing I wanted to try and do was add some indication of the weather conditions at the time a session took place; where possible I wanted it to be something a little more useful that "it's a bit chilly" or "it's somewhat breezy". Back in October I acquired and set up a simple wireless indoor/outdoor hygrometer/thermometer that I acquired from Maplin and, since then, I've been recording the temperature and humidity with each of my observing logs.

This, of course, wasn't really enough. What I really wanted was something that could feed data to one of my computers so that I could keep constant weather logs.

As of last week I'm now the owner of a WS3600 personal weather station. Not only does it measure temperature and humidity it also measures atmospheric pressure, precipitation and wind speed and direction. Even better, you can pull a data feed off it onto a computer.

After giving it a test indoors last week (it seemed to work just fine) I quickly realised that I needed to have a good think about where I was going to site the instruments — especially the anemometer. My back garden is reasonably sheltered and the best place for the anemometer would seem to be above the roof of my office. So, with this in mind, yesterday I ordered an installation kit from Skyview. This will allow me to attach the instrument to the side of the office and have it above the line of the roof. I'm expecting delivery in the next day or so.

I'm not sure when I'll get the chance to do the installation; with some luck (and if the weather plays ball <g>) I might get the chance to do it this weekend. If I don't get the chance any time soon I'll probably make it a little project for the xmas break.

After installation the plan is to give it all a good test and see how well the readings compare with other personal stations in my area. At the same time I'll also have a play with the computer link and see what sort of software is available for talking to the base station. The WS3600 comes with software for Microsoft Windows but, ideally, I'd quite like to hook it up to one of my GNU/Linux boxes.

Once that's all working I intend to build a website for displaying the logs and, if all goes well, I'll see about setting up a feed to The Weather Underground.

File Under: Personal Weather Station, WS3600, Installation, Weather website.

Blame the weather

Oh, wait, I did that one once already and it sort of doesn't work so well this time around.

Well, having recently acquired a personal weather station I thought it might be fun to also keep a record of my experiences of setting it up and building a website around it and, once that's all done, write about notable events that follow.

So, here we are: "davep's wx".

File Under: Weather Blog, Personal Weather Station, Geek Toys.