Figure 2: Idealized, cutaway section through a TILT-OBS; expanded
view illustrates the high sensitivity tiltmeter. Two orthogonally
mounted low gain inclinometers are mounted on the center ring, and the
high gain inclinometers and the high sensitivity tiltmeter are fixed to
the seismometer block. The tiltmeter is mounted on a triangular plate
that is independently leveled with motor-driven micrometers.
The dynamic range of the high gain inclinometers is matched to the
tolerance of the OBS leveling mechanism.