Jewell Instruments 520 Geodetic Tiltmeter

The Jewell Instruments Model Geodetic Tiltmeter is designed for projects demanding the maximum in resolution and stability. Applications include leveling and alignment of antennae, measurement of earth tides and crustal deformation, volcano monitoring and telescope pointing. With resolution smaller than 10 nanoradians, Model 520 is excellent for use in all static applications, or as a sensitive low-frequency accelerometer.

The Model 520 uses the vertical gravity vector as its stable reference. Electrolytic tilt sensors measure rotations in two orthogonal vertical planes. The sensors can be described as electronic spirit levels, each containing a bubble in a conductive liquid. As the instrument tilts, platinum electrodes in the sensor walls move into or out of the bubble and the area covered by liquid changes. This effect changes the electrical resistance between opposing electrodes so that the sensor behaves as a precision voltage divider, capable of detecting even the smallest rotational movements. Hand assembly and use of the highest-quality, low-noise components result in unrivaled sensitivity, stability and dynamic range.