16 year old Jan Hagnberger from Schenkenzell located in the beautiful Black Forest not only has a very special hobby but also a talent for weather technology. He owns two professional weather stations equipped with a lot of different sensors. One of them is the WS500-UMB from Lufft, which he installed and networked himself. How this all started and what he invents in order to make the system work, he explains in this blog post…

 Photo source: Reinhard Sester, Fotolia

At the age of about 10 years I was passionate about three things: weather observation, airplane model-making and downhill cycling. As for the flying of model airplanes the wind is of great importance, I started to build a wind detector, also called anemometer. The first one consisted of wooden crossed cups  and a bicycle speedometer for the wind speed detection. Gradually, I had improved my self-made anemometer (the anemometer was partially made of brass, ball bearings were added, etc.) and had occupied myself with the construction of a wind vane. After a short time, I wanted more: Without further ado, the self-built wind measuring station was extended with a thermometer, hygrometer and a rain gauge from the DIY store. Later a big Christmas wish was fulfilled by an automatic weather station. Unfortunately, this one had no computer access. After a brief check of my bank account, I ordered a semi professional weather station with computer connection. Since then, my station had delivered almost gapless weather recordings of my location. This was in 2011.

Now, I’m the proud owner of two professional weather stations, whereof one includes a Lufft WS500-UMB sensor. The quality of these new weather stations can’t be compared to my previous ones of course…

The compact weather sensors from Lufft

The Lufft WS family members are intelligent weather sensors, which measure different parameters such as wind speed, wind direction, air pressure, air temperature, and relative humidity. A further external sensor can be added as well. The electronic unit inside of the sensor converts the signals of the integrated measuring transducer, such as temperature resistance, into a digital reading. Afterwards, they are processed further for calculations and in order to get minimum, maximum and average values. The edited measurement data can be requested via the weather sensor’s RS485 interface. It offers different kind of serial protocols, such as SDI-12, Lufft UMB-binary etc.

My weather station is located in Schenkenzell, lying about 375 m above the mean sea level. Schenkenzell belongs to the beautiful Black Forest. Since beginning of the year 2015, also a WS500 compact weather sensor from Lufft is part of our measurement field. Its measurement values are transferred to the internet automatically every 10 minutes. The data transport is performed by the selfmade and still improving “JaWe-Log” remote data transfer unit (RTU).

This low power consuming (< 1 W) unit consists of one USB, two RS232, one RS485 and one Ethernet interface. It requests the detected measurement values of, for example, a compact weather sensor or data logger  and transfers them to a web server. If necessary, the RTU buffers it within an own, non-volatile storage. Alternatively the data be issued through a serial protocol, such as for a scoreboard connected via RS232.

The WS500-UMB is linked to the JaWe-Log RTU through an RS485 interface. As soon as the WS and the RTU are powered, both devices start working immediately. The compact weather station requests the integrated measuring transducers, collects the measurement readings and transforms them into different static values. The JaWe-Log RTU sends specific measurement data orders to the weather station every ten minutes. Its answer is the requested data. These answers are received as well as processed by the JaWe-Log RTU and error checked with the help of CRC checksum. If no errors are found, the JaWe-Log sends the values to my web server via TCP/IP protocol. Otherwise the request is restarted. On the webserver the data are saved in two different MySQL data bases – one with average and another one with extrem measurement values. With the help of JavaScript, dynamic graphics are created and provided on my homepage.

The weather station has worked realiably and delivers very good measurement values. There are only very few data gaps caused by maintenance activities.

For me, it is a lot of fun to evaluate and analyze the collected measurement information. For the evaluation, I use a self-made portal together with a third party software for my computer. It is very interesting to compare my station’s values with neighbors’ stations placed in different envrionments. I’m very happy with my new station and it even exceeded my expectations.

Future plans

The next step is to search and invest my saved money into a new (used) mast of 8 to 12 meters length plus foundations. Unfortunately the price for a professional mast is quite high and not to be underrated. If the sensors are installed in standardized height a cooperation with Meteomedia respectively MeteoGroup is possible and would be a dream.

Interesting recorded weather events

In Schenkenzell interesting weather or storm events occur quite seldom. In case a storm attacks, it mostly is very strong, such as on 27 th of April 2015: On this Monday morning a severe local storm along with torrential rainfalls, lightnings and thunder as well as hail and strong wind gusts took place. Within less than one hour, 100 millimeters of precipitation was recorded, whereas the whole year’s precipitation amount counted 800 to 900 millimeters in average. This strong rain led to floodings and landslides. Also my station was affected. Luckily, the damages were not very extensive. During the storm, the air temperature dropped from 17.2 to 11.2 °C fastly. Since my anemometer is fixed in a height of five meters only, I wasn’t able to measure the wind gusts exactly but there were gusts of 34km/h recognized after all.

On Friday, the 20th of March 2015 a partial eclipse of the sun which could be watched  in whole Germany – at least where the sky was cloudless. The residents of north western Europe were even able to watch a total eclipse of the sun. Luckily, in Schenkenzell this event was clearly visible. Therefore also the measured values of my weather station represented the sun eclipse very well: The global radiation of the sun dropped from 437 W/m² at 08:50 UTC to 144 W/m² at 09:40 UTC. At the peak of the sun cover, the pyranometer read 141,8 W/m² only. Afterwards the it slowly increased again to a typical value. On cloud free summer days the radiation values are normal at a level of up to 1000 W/m.

Station records in Schenkenzell since 2011:

• Highest air temperature: 39,6 °C on 5th of July 2015
• Lowest air temperature: -15,1 °C on 6th of February 2015
• Highest air pressure (reduced to sea level): 1041.9 hPa on the 6th of March 2015
• Lowest air pressure (reduced to sea level): 975.4 hPa on the 30th of January 2015
• Strongest wind gust: 99,7 km/h on the 16th of November 2011 (Orcan “Joachim”)
• Maximum daily pecipitation: 130 mm on the 27th of April 2015

The records partly come from different weather stations which have been in use for a while.

In case you are interested in more details, please visit my homepage at www.Wetter-Schenkenzell.de, where also the current weather is displayed and evaluated. More about the WS500-UMB you can find at www.Lufft.de.

About the author My name is Jan Hagnberger and I’m 16 years old. After the summer holidays, I will attend the technical high school. Since 2015 I’m a proud owner of a Lufft weather sensor. Moreover I love to develop and program (C/ C++ and PHP) new technical tools. As I’m highly interested in weather and the technological background of weather sensors, this became my hobby. With the compact Lufft weather sensor WS500-UMB a long-held wish of mine was fulfilled!