| Which off-the-shelf electronic pressure sensor component (part number) would | be used to measure altitude of a baloon starting its journey from sea level | (0 meter) to 15000 feet (4,572 meter) ?
Well, this doesn't exactly answer your question as asked, but it might (or might not) be more useful than actually answering your question. (Which others have done anyways.) And you did ask in rec.models.rc.air, so I'll answer in that context ...
If you're looking to record the altitude over time, and want it small, accurate and relatively cheap, get the RAM2 at
It costs about $100 and will record 9 hours of altimeter data at one data point/second with a resolution of about one foot. And it only weighs 7.5 grams.
If you're looking to know how high your balloon is and want this transmitted in real time, you may want a variometer. There's several to choose from, but the Picolario at
is a popular one. Alas, it costs just short of $400. (But there are other options that are cheaper, but have fewer options.) I don't know if these would have 15,000 feet of range, however -- though you might be able to use a scanner and a highly directional antenna to increase the range.
Another option is the Flight Data Recorder at
and it can both transmit and record information, and can keep even more information than just altitude. It also has a GPS option that might be useful.
Note that these altimeters give altitude data that is a good deal more accurate than a GPS. You may or may not care, but the difference is there.
Of course, if you want something that you can tie into something else on the balloon, then none of these are likely to be what you want, but you might find them useful as a starting point of something you homebrew.