A note on the response characteristics of the VACM compass

Author

Patch, S. ; Beardsley, R. ; Lentz, S.

Author_Institution

Courant Inst. of Math. Sci., New York Univ., NY, USA

fYear

1990

fDate

3-5 Apr 1990

Firstpage

129

Lastpage

133

Abstract

Several simple laboratory experiments have been conducted to study the dynamic behavior of the vector averaging current meter (VACM) compass. These experiments demonstrate that the combined eddy current and bearing friction torque on the compass magnet is proportional to the angular velocity difference between the compass magnet and housing. This combined friction torque tends to critically damp the free oscillation of the compass as originally intended by the compass´s designers. Step-forcing experiments on the six compasses indicate all (undamped) resonant period of 3-5 s at 41°N. Periodic forcing experiments with one compass yield a more accurate determination of the resonant period of 4.0 s

Keywords

flow measurement; oceanographic equipment; oceanographic techniques; VACM compass; angular velocity; bearing friction torque; compass magnet; direction determination; dynamic behavior; eddy current; measurement technique; orientation; resonant period; response characteristics; vector averaging current meter; Aluminum; Damping; Eddy currents; Equations; Friction; Magnetic levitation; Magnetic resonance; Sea measurements; Torque; Velocity measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Current Measurement, 1990., Proceedings of the IEEE Fourth Working Conference on

Conference_Location

Clinton, MD

Type

conf

DOI

10.1109/CURM.1990.110899

Filename

110899