12 August, 1998

Wednesday, August 12, 1998

Preparation for another Ozonesonde Launching:

The ozonesonde was prepared 3 to 7 days before the next launch. The steps are very similar to those of the day of the launch as listed below.

Before launching in the lab: every time on the day of the flight the following has to be prepared in order to assure good data collection: * The correct concentrations of potassium-iodine solutions in the cells allows for correct current and consequently correct ozone measurements. Therefore, the solutions of the cathode and anode cell has to be changed. (The solution was added to the cell about 5 days before in preparation procedures before the flight)

* Air with no ozone or low needs to be pumped through the ozonesonde to record the background ozone.

* In order to check the response of the sonde to changes in ozone concentrations run on 5 microamps of ozone for 10 minutes and measure the time it takes to recover from 4 to 1.5 microamps. This recovery time tells if the cells in the sonde are properly working.

* The flow rate needs to be taken to measure how fast air/ozone

is pumped through the cells. This is done with the Bubble-Flow-Meter ( See also Aug. 6th ) To correct for the humidity concentration in the air under lab conditions, we also measure the humidity flow rate. The corrected flow rate will be used in the computer program

* At the launch site the background ozone, surface temperature, humidity, and surface pressure are recorded and the launch can begin. Check the following entry about the preparation of the balloon and the actual launching!

The photo below shows me checking the flow rate of the ozonesonde. This is done with a Bubble Flow Meter and has to be done several times. The bubble rises in a tube and the travel time over a certain distance is recorded and it is an input for the computer ozone calculation. The flow rate shows haw fast the piston pump will pump air/ozone through the electrochemical cells.