{"id":1104,"date":"2019-08-01T18:39:00","date_gmt":"2019-08-01T17:39:00","guid":{"rendered":"https:\/\/sondehunt.de\/?p=1104"},"modified":"2019-08-01T18:59:31","modified_gmt":"2019-08-01T17:59:31","slug":"launch-of-an-ozone-sonde-in-uccle","status":"publish","type":"post","link":"https:\/\/sondehunt.de\/language\/en\/archive\/1104","title":{"rendered":"Launch of an Ozone Sonde in Uccle"},"content":{"rendered":"\n

On 29.07.2019, on my way back from\nthe Tomorrowland Festival in Belgium, I organized a trip to the KMI in Uccle to\nbring back my two Belgian ozone sondes and visit the institute and attend an\nozone sonde launch.<\/p>\n\n\n\n

The KMI has now had a continuous\nozone measurement series of radiosonde ascents for almost exactly 50 years.\nLaunches are always Mon, Wed and Fri at 11:30 UTC. ECC ozone sondes are used,\nsince the middle of the 90s, before Brewer-Mast sondes were used.<\/p>\n\n\n\n

In general a normal radiosonde, here a Vaisala RS41, is used for ozone sounding. The ozone measuring device is connected to this sonde, which consists of an electrochemical reaction cell, a sampling pump, a control board and the necessary batteries, and is connected in a polystyrene box. If you don’t already know it, take a look at the Vaisala Ozone Sounding Guide<\/a>, which is very good and detailed.<\/p>\n\n\n\n

The preparations on the launch day\nstart with the electrochemical testing of the cell starting at 7:30 UTC. We reached\nthe institute at 9:00 UTC and were immediately taken into the balloon hangar to\ninflate the balloon. 1200 g balloons from Totex are used, which are filled with\nhydrogen to a counterweight of 2400 g. The hydrogen storage is located about 30\nm away from the balloon hangar and is connected to it via underground piping.\nWhen the takeoff volume has been reached (the balloon is a  considerable bit larger than a normal helium\nballoon from the automatic launch system despite the hydrogen filling), the\nballoon is tied up with cord and attached to the parachute. The balloon is\nremoved from the filling device and attached to a weight, the cord between\nparachute and probe is measured and attached to the parachute.<\/p>\n\n\n\n

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the filled ballon can stay in the hangar for a few hours, while the other preparations take place<\/figcaption><\/figure>\n\n\n\n

Then we went on to the laboratory where the electrochemical preparations take place and which is located in the basement of the institute. This is where the ozone sonde supplies and the test station are located. During the preliminary examination for the next but one ascent, my sondes were handed over. For the staff in Uccle, it is okay if the finder opens the sonde to reduce the packing volume and to remove the batteries. The air intake hose is also replaced each time the sonde is launched. <\/p>\n\n\n\n