Evaluation of property change of pressure sensor installed on TRITON buoys

Abstract

A property change of strain gauges type pressure sensor installed on TRITON buoys was investigated for correction of pressure and salinity data. Output data from pressure sensors on deck after recovery indicated overestimated value as a result of hysteresis of pressure sensor. A value of overestimate surpasses 10 dbar in the most remarkable case, and it becomes an error of 0.005 psu by salinity conversion. It is critical for our aim of salinity measurement accuracy (0.02 psu). Moreover, sensor calibration data reveals larger influence of hysteresis under actual high-pressure condition. It is also obvious that hysteresis occurs at a stage put in high-pressure installed depth, at least 10 days mooring, and its value is different among each sensor. This result suggests that removal of a bias, which corresponds to hysteresis induced by calibration data, become effective.