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US 5,170,567 AGranted
Electronic inclinometer
AssigneeThe Stanley Works
InventorsKelvin R. Davis, Stephen J. Bates, Andrew J. Murray
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AssigneeThe Stanley Works
InventorsKelvin R. Davis, Stephen J. Bates, Andrew J. Murray
Estimating the term…
A sensor for an incination measuring device which comprises a capsule (3) part-filled with a conductive liquid. First to fourth electrodes (A-D) are disposed within the capsule in contact with the liquid. An electrical signal is applied between electrodes (C, D) and one then the other of electrodes (A, B), to derive a signal indicative of the degree of immersion of the electrode (A), and then the electrode (B) within the liquid. The ratio of these signals is related to the angle of inclination of the capsule about the reference axis (O) and relative to a first reference angle defined at the gap between the electrodes (A, B). The capsule (1) is also constructed to compensate for thermal effects, by forming the sides of the capsule so that they are responsive to pressure change within the capsule caused by thermal expansion of the contents of the capsule to expand the volume of the capsule, to keep the level of liquid therein constant.
A capsule, part filled with a liquid, the volume of the liquid varying as a function of temperature and the capsule being elastically deformable in response to temperature-induced pressure change within the capsule, so that the internal volume of the capsule is variable in dependence upon temperature and whereby dimensions and material of walls of the capsule are selected to provide (a predetermined relationship between the level of liquid within the capsule and temperature) that the level of liquid remains substantially constant with respect to temperature over a temperature range.
A capsule, part filled with a liquid, the walls of the capsule being formed so that a temperature-induced pressure change within the capsule will cause the walls of the capsule to deform elastically to maintain the level of the liquid in the capsule substantially constant.
A method of calibrating an inclination sensor of the form comprising a capsule part filled with a liquid, the position of the liquid within the capsule being indicative of the angle of rotation of the capsule about a reference axis, a plurality of electrodes disposed within the capsule for sensing said position within an angular range, an excitation source, a sensing circuit and means for connecting said electrodes to the sensing circuit and to the excitation source allow measurement of a plurality of electrical characteristics of the liquid which together are indicative of said position, said method comprising the steps of placing the sensor at least two known angles .theta., measuring the corresponding sensed angles .theta.' and calculating from the known and sensed angles calibration values a and b where:
Dependencies are inferred from the claim text.