About This Site

This website was created to display the weather from a private weather station, located at Vallaheiane.

Vallaheiane is near to Nesttun, Smørås and Kaland, and 12km south of Bergen.

Our site and station are both a hobby and experiment in weather-related computing. This site has run weather station reports for several years.

The original weather station used components from Dallas Semiconductor. The sofware used was the OWW software for the 1-wire weather station. It has been operational since 28^thSeptember 2003. To construct, set up and test the weather station was straight forward, however since this thing has been sitting on my shelf for about 3 years before I got around to assembling it, there must have been some reason for not getting around to it sooner?

The main work required was to calibrate the rain gauge. I was also a little worried about snow and ice and how that would affect the rain gauge. The rain gauge is a large funnel with a small hole. Water is caught in the funnel and drips through to a tipper. The tipper then tips over when full and increments a counter. So the number of counts multiplied by the volume of the tipper can be used to determine the amount of rainfall. This gives a good averaging effect since the water is collected over a relatively large area. According to the calibration instructions 1 tip should be equivalent to 0.01 inches, and 16 US ounces of water down the funnel is equivalent to 1 inch. So what needs to be done is to drip 16 ounces of water through so that you get exactly 100 tips. 16 ounces is apparently 473.12ml, and after carefully measuring this amount and dripping it through I managed to adjust the tipper to give 100 counts. However the funnel is 15cm in diameter and I checked the calibration by determining the metric volume required for 1 inch of rain in a circle of 15cm diameter. The answer is slightly different and from pi.r².h we get 433ml. So this is what I used and managed to adjust the tip volume so that we get 99 tips for 433ml of water dripping through. It is almost impossible to adjust the tipper finely enough to add one more tip (I ended up with 2 or 3) so we're stuck with a built in error of 1%!

To solve the problem of snow and ice I consulted a local electrician and had made up a lead with 0.5m self regulating heater cable (the kind used for heated floors or for keeping water pipes from freezing in winter). The heater cable is attached to abount 10m of power cable and is plugged into the mains. It is all completely waterproof and is mounted inside the raingauge to keep the tipper and funnel from freezing.

The site has since been upgraded and now uses a Davis wireless weather station (see equipment).

History

Sept. 2003 - Site goes live, new AAG/Dallas 1-wire station.
Oct. 2003 - Barometer and hygrometer added.
Jan. 01, 2006 - New site goes live, new Davis weather station.