The WS 3600 system comprises an indoor LCD display unit with a touchscreen and a suite of sensors that is able to measure temperature and humidity, both indoors and out, atmospheric pressure, wind speed and direction and rainfall. The display unit communicates with the outside sensors either via a cable or a 433MHz radio link and includes sensors for temperature, pressure and humidity. Most of this information can be displayed here (some data are only accessible by scrolling through related data eg rainfall can be displayed as rain in the last hour, last 24 hours or previous week). Connection to a PC is also possible, which then allows the creation of graphs of the history of any measured parameter. The suite of outdoor sensors comprises three modules, a rain gauge, a wind sensor, measuring speed and direction and a combined Thermo-Hygro unit which measures temperature and humidity. It also provides the comms link for the rain gauge and the wind sensor which are connected to it via cables. I wanted to place the wind sensor unit as high as possible in an effort to minimise the influence of surrounding buildings and trees, so it is mounted on the TV aerial mast just below the aerial. This then places a constraint on the positioning of the thermo-hygro unit as it must be within reach of the 10 metre connecting cable. To this end, it is about fifteen feet above ground level on the gable of the house which is almost North facing. Whilst this is not the ideal sitution for accurately measuring temperatures, it is out of direct sunshine for most of the day and can be reached from a window to check batteries etc if necessary. The only obvious problem is that the sun can shine directly on to the sensor unit after about 17:00 GMT but only during the summer months. As it too has to be connected by a cable, the rain gauge is fixed to the side of a dormer roof, just below the chimney supporting the TV aerial.
At approx 17:00 UTC, the sun hits the temperature sensor and gives false results (assuming of course that it is not cloudy) In an effort to correct this problem and tidy up the cable installation, the thermo-hygro unit was moved closer to the eaves of the roof. Since this was done at the begining of September 2006 I do not yet know if it has been successful or not. Occasionally there are short periods of data loss across the radio link between the outdoor sensors and the base station and some erratic readings, particularly noticable in wind gust data. Relative pressure setting adjusted at 19:00 UTC on 21st October 2005. Increased by 1.8hPa based on information from Motherwell station obtained from the skylink weather web site. www.skylinkweather.com
Further information from the La Crosse (France) web site