Nevada Space Grant
We use little Hobo data loggers. They are lightweight, They last a year on one battery, they can survive cold temperatures, moisture and are pretty rugged. At this stage we use only an internal/external temperature Hobo ($75).
There are all sorts of data loggers. Hobo makes 8 & 12 bit data loggers as well as serial or USB loggers. There is also quite a variety of measurement options to choose from.
Uses easy to use software to set data loggers measurement frequency, set active channels, and delayed start.
Tough and lightweight
Software allows for instant field download of data into PC (creates graphs and numerical data)
With internal and external temperature channels active it will log several hours of data taking measurements every 3 sec.
All sensors, cables, and software costs extra.
We also datalog our GPS onboard using a Sparkfun
Logomatic board ($60). This board uses a SD memory card (16 MB can hold
weeks of data). Small and lightweight, perfect for ballooning. You will
need to use a Max232
chipset (a.k.a level shifter kit) to convert the GPS voltages to