The Effect of Barometric Pressure Variation on the 'U.S.O.' Long-Period Seismometer

摘要

The particular manner of mechanical construction of the Long-Period U.S.O. package is responsible for the pressure sensitivity of the LP-X component. The effect seems to be linear with pressure for periods larger than the seismometer period and short compared to the feedback signal time constant. Since the pressure induced displacements are considered as very undesirable noise for the instrument as either long period seismometer or as tiltmeter the borehole was pressure sealed and the effect removed. Records are presented to demonstrate the effect. (Author)