BMP085 Pressure Sensor at High Altitude
Tim, Alex, and I launched a balloon in September of last year. On it, we flew an IR camera, pressure sensor, and a GPS on an Arduino and an APRS tracker.
An IR photograph taken from about 85,000 feet.
The sensors and Arduino getting ready for flight
With this sensor configuration, we were able to get GPS data from above 60,000 feet (at which GPS usually shuts off), and compare this with the pressure sensor we were flying, a BMP085 we bought from sparkfun. The datasheet for this sensor states that it’s rated for pressures as low as 30000 Pascals, or about 30,000 feet above sea level.
Pressure vs. Altitude
However, it seems that it worked for higher altitudes, too. At the highest altitude we reached, 26898 meters, the BMP085 recorded a pressure of 1781 Pa, or about 27350 meters above sea level. So it seems that the BMP085 works at altitudes above 30,000 feet, just not as accurately.
Greg Klein's Blog 
Great project! My son and I are doing something very similar and launching an android and arduino. I am curious though, how did you know you reached 90k feet if your GPS stopped at 60k feet and the BMP085 lost accuracy above 30k feet?
Thanks!
Craig
Craig
March 11, 2011 at 5:07 pm
Sorry if I was unclear, but we used a GPS module that works above 60kft: http://www.sparkfun.com/products/9171
gregklein
March 12, 2011 at 3:36 pm
Hi,
We are in the process of launching our very own balloon using the BMP085 sensor. You mentioned that the sensor seemed to work for higher altitudes. In comparison with the BMP085 and the GPS module you used, how much deviation occurred between readings? Could you possibly provide a graph of the deviations that occurred between modules?
Thanks.
Austin
April 4, 2011 at 5:24 pm
All of our data from the flight can be found here: http://condor.hibal.org/data/
gregklein
June 2, 2011 at 4:39 pm
[…] v plánovanej výške okolo 30 km nad morom bude okolo 10 hPa. Greg Klein s Alexom a Timom overili vo svojom balónovom projekte, že tento senzor meria aj nižšie hodnoty tlaku. Zrejme už mimo tolerancií a presnosti […]
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