statoscope
/ˈstætəˌskoʊp/
noun
- An instrument that measures small changes in altitude or atmospheric pressure, used especially in aircraft and balloons.
- The statoscope showed that the balloon was slowly descending even though the pilot thought it was level.
- The pilot used a statoscope to detect tiny altitude changes during the flight.
- Weather balloons carry a statoscope to record pressure variations as they rise.