Oh, I totally forgot about the internal valves in the pump. I thought LittleInch and btrueblood were reffering to the valves connecting the tubes that force air to go through particular filters.
Contacting the people involved sounds like a great idea and I will definitely give it a try as soon...
Thanks everyone for your replies!
We tried consulting it with the manufacturer but they said they do not have any data about their pumps' performance in stratospheric conditions so they simply can not guarantee that it will work.
The reason we chose Boxer 7KQ is that an older version of this...
My science club is planning on releasing a high-altitude balloon with a vacuum pump on board in order to filter air and collect microbiological samples.
It will fly to an altitude of around 30 km.
The sampling system will be similar to the one described here (see chapter 2.1)...
