to my weather station
How the weather station began
| My interest in
the weather began many years ago with a fascination with the
temperature, I liked extremes.My fathers greenhouse max/min thermometer
didn't stay in the greenhouse very long. I was always looking
at the temperature. On holidays I would always be able to identify
where all the thermometers were. In the past few years I recorded
daily maximum and minimum temperatures on the kitchen calendar,
including the prevailing weather.
|These early readings
were taken using an RS digital Max/min thermometer read every
morning. A 3 metre lead allowed the temperature bulb to be placed
on a North Facing wall. It was very reliable and handy to read
the outside temperatures from the house. Th readings began to
fail as -40c and LLL were indicated on warm sunny days. The unit
||The replacement was
an Oregon Scientific Cable free Thermometer. Again the transmitter
was mounted on the North facing wall. As my interest in accuracy
grew I realised that this North facing wall was giving errors,
readings that were not falling to what I expected during the
night and probably not giving a true daytime temperature. Various
books and references on the internet suggested the answer.
I needed a screen a Stevenson
screen....., but the price......! Something cheaper....... thats
it I will make my own. Several hours in the garage and hey presto
a home made screen well it looked a little like a screen. It
consisted of several plastic cartons about 12" * 5"
cut to a depth of 1-1.5" and because they sloped slightly
they fitted together (with a little glue and some cable ties).
Air could flow through the sensor was sheltered from direct sunlight.
It worked, the only thing was that stuck in the middle of the
garden at 4' above the grass it did look a little unsightly.
As my interest grew I began looking
for something a little more sophisticated. Visits and questions
to Uk.sci.weather newsgroup provided me with a potential answer
a Davis Weather Monitor. It measured well....everything, and
was what I wanted, the price was reasonable.
|With that in mind I
began to save up and couldnt resist starting my weather station
off with a the Davis Gill screen, my existing transmitter would
fit inside until I could afford to purchase the complete Davis
| I also constructed
a simple rain gauge using the old Blue Peter principle,an empty
lemonade bottle with the top cut off and turned around forming
a funnel. Inside the base was a narrow empty bottle (Worcestershire
Sauce I think).Calibration was simply a case of measuring 10mm
in the large bottle emptying it into the smaller and marking
the side. It was quite easy to get values of 0.5mm in this way.
Not very accurate I know but I could look at comparisons between
different days of rainfall
| Having decided
where my sensors were to be fitted I purchased some 15mm plastic
conduit and excavated the garden from the house to the location
for the rain gauge and again to the Gill screen. A 3" square
wooden post allowed the Gill screen to be securely fixed along
with the conduit up the side of the post to a conduit box. I
drilled The wood and pushed through some conduit for the cable.
A 25mm conduit ran through the garage to keep all the cables
neat, after all I had to keep the wife happy.
| In late May 2000
I had saved enought to purchase a Davis Complete Weather Station.
My cheque was sent to Prodata,
and just over a week later (Tuesday 13th June) my parcel arrived.
|| As all the sensor
sites had been provided with conduit runs from the house, the
installation was simple. All I needed was some help pulling the
cables in.The temperature Humidity sensor was the easiest to
sort out and it was up and running late on Wednesday 14th June.
The display on the console inside now displaying a temperature
Thursday 15th June I tackled the
annemometer. I had fixed the brackets for the annemometer several
days before. What a task perched on the top of a ladder at the
apex with a power drill.
The 3m mast would give me a 1.6
metre clearance from the ridge. As the hard work was done the
annemometer only took 90 minutes to install. The unit was aligned
with true North and away she went.
the Raingauge I had bought a small 12" square paving slab
drilled the bottom with a 20mm hole and four fixing holes for
the rain gauge. A small foundation with a mortar mix allowed
the paving slab to be lowered onto the conduit and bedded down
with a spirit level. The next day (Saturday 17th June) I screwed
down the base and pulled the sensor cable in. Connected her up
and tipped the bucket, 0.2mm registering on the display, another
success. Installing in this way completely hid the connecting
Ultimately I knew that to
maintain readings when on holidays I would require a Weatherlink
Datalogger. More money!
Well birthday approaching I could
see a way of purchasing one. The 1st August and I now have my
Weatherlink. The unit unit connects between the Davis weather
console and the computer. I have set the datalogger to sample
every 8 seconds and provide the average of those values every
15 minutes. At this rate the logger will store 15 days worth
of readings enough to cover a two week holiday.
If you have any comments or questions please e-mail me.