Vibration sensor utilizing eddy currents induced in member vibrating in the field of a magnet

Claim 3

A device in accordance with claim 1, further inducing at least one pole piece positioned in the flux path of the magnet means.

Claim 10

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a longitudinally vibrated bar, wherein said acoustic signal causes said bar to vibrate, comprising, a first eddy current device positioned at a first point along the longitudinal axis of said bar to measure one component of motion of vibration of said bar, and a second eddy current device positioned at a second point along the longitudinal axis of said bar to measure another component of motion of vibration of said bar, with the magnitude of the two measurements being different and said measurements being used to calculate the transmitted power.

Claim 11

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a longitudinally vibrated bar, wherein said acoustic signal causes said bar to vibrate, comprising, a first eddy current device positioned at a first point along the longitudinal axis of said bar to measure one component of motion of vibration of said bar, and a second eddy current device positioned at a second point along the longitudinal axis of said bar to measure another component of motion of vibration of said bar, with the magnitude of the two measurements being different and said measurements being used to calculate the transmitted power.

Claim 12

A meter in accordance with claim 6, wherein both devices are designed to measure the tangential components of motion and said first point is a point of maximum longitudinal amplitude of motion and said second point is a point of minimum longitudinal amplitude of motion.

Claim 13

A meter in accordance with claim 7, wherein the first point is a loop of longitudinal motion and the second point is a node of longitudinal motion.

Claim 14

A meter in accordance with claim 6, wherein both devices are designed to measure the normal components of motion and said first point is a point of maximum normal amplitude of motion and said second point is a point of minimum normal amplitude of motion.

Claim 15

A meter in accordance with claim 9, wherein the first point is a node of longitudinal motion and the second point is a loop of longitudinal motion.

Claim 16

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, a first eddy current device positioned at a point along the longitudinal axis of said bar to measure a first component of motion of vibration of said bar, and a second eddy current device positioned at the same point as said first device to measure a second component of motion of vibration of said bar, said second component being orthogonal to said first component.

Claim 17

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, a first eddy current device positioned at a point along the longitudinal axis of said bar to measure a first component of motion of vibration of said bar, and a second eddy current device positioned at the same point as said first device to measure a second component of motion of vibration of said bar, said second component being orthogonal to said first component.

Claim 18

A meter in accordance with claim 11, wherein said first eddy current device is designed to measure the tangential component of motion and said second eddy currenT device is designed to measure the normal component of motion.

Claim 19

A meter in accordance with claim 12, wherein both devices are positioned at a loop of longitudinal displacement.

Claim 20

A meter in accordance with claim 12, wherein both devices are positioned at a node of longitudinal displacement.

Claim 21

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis, wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, a first eddy current device positioned at a loop of longitudinal vibrational motion of said bar to measure the tangential component of motion at said loop further including, first magnet means, shaped to conform to the periphery of said bar and magnetized radially, relative to the longitudinal axis, said magnet being positioned near the vibrating surface to supply a constant magnetic field thereto, first coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being contiguous to a small area of said surface and being wound about the periphery of said body, and a first means electrically coupled to said first coil means for measuring the voltage induced by said varying magnetic field; and a second eddy current device positioned at a node of longitudinal vibrational motion of said bar to measure the tangential component of motion at said node, further including, second magnet means, shaped to conform to the periphery of said bar and magnetized radially, relative to the longitudinal axis, said magnet being positioned near the vibrating surface to supply a constant magnetic field thereto, second coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being contiguous to a small area of said surface and being wound about the periphery of said body, and second means electrically coupled to said coil means for measuring the voltage induced by said varying magnetic field, whereby the measurements of both eddy current devices are used to calculate the transmitted power.

Claim 22

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis, wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, a first eddy current device positioned at a loop of longitudinal vibrational motion of said bar to measure the tangential component of motion at said loop further including, first magnet means, shaped to conform to the periphery of said bar and magnetized radially, relative to the longitudinal axis, said magnet being positioned near the vibrating surface to supply a constant magnetic field thereto, first coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being contiguous to a small area of said surface and being wound about the periphery of said body, and a first means electrically coupled to said first coil means for measuring the voltage induced by said varying magnetic field; and a second eddy current device positioned at a node of longitudinal vibrational motion of said bar to measure the tangential component of motion at said node, further including, second magnet means, shaped to conform to the periphery of said bar and magnetized radially, relative to the longitudinal axis, said magnet being positioned near the vibrating surface to supply a constant magnetic field thereto, second coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being contiguous to a small area of said surface and being wound about the periphery of said body, and second means electrically coupled to said coil means for measuring the voltage induced by said varying magnetic field, whereby the measurements of both eddy current devices are used to calculate the transmitted power.

Claim 23

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis, wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, a first eddy current device positioned at a loop of longitudinal vibrational motion of said bar to measure one component of motion at said loop, further including, a first means for supplying a constant magnetic field to said bar surface, one component of said magnetic field being substantially perpendicular to the component of motion being measured, a first body of high permeability positioned contiguous to a small area of said body surface, first coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being wound about said first high-permeability body, the axis of said winding being parallel to the component of motion being measured, and first means electrically coupled to said first coil means for measuring the voltage induced by said varying magnetic field; and a second eddy current device positioned at a node of longitudinal vibrational motion of said bar to measure the same component of motion as measured by the first eddy current device, further including, a second means for supplying a constant magnetic field to said bar surface, one component of said magnetic field being substantially perpendicular to the component of motion being measured, a second body of high permeability positioned contiguous to a small area of said body surface, a second coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being wound about said second high-permeability body, the axis of said winding being parallel to the component of motion being measured, and second means electrically coupled to said second coil means for measuring the voltage induced by said varying magnetic field, whereby the measurements of both eddy current devices are used to calculate the transmitted power.

Claim 24

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis, wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, a first eddy current device positioned at a loop of longitudinal vibrational motion of said bar to measure one component of motion at said loop, further including, a first means for supplying a constant magnetic field to said bar surface, one component of said magnetic field being substantially perpendicular to the component of motion being measured, a first body of high permeability positioned contiguous to a small area of said body surface, first coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being wound about said first high-permeability body, the axis of said winding being parallel to the component of motion being measured, and first means electrically coupled to said first coil means for measuring the voltage induced by said varying magnetic field; and a second eddy current device positioned at a node of longitudinal vibrational motion of said bar to measure the same component of motion as measured by the first eddy current device, further including, a second means for supplying a constant magnetic field to said bar surface, one component of said magnetic field being substantially perpendicular to the component of motion being measured, a second body of high permeability positioned contiguous to a small area of said body surface, a second coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being wound about said second high-permeability body, the axis of said winding being parallel to the component of motion being measured, and second means electrically coupled to said second coil means for measuring the voltage induced by said varying magnetic field, whereby the measurements of both eddy current devices are used to calculate the transmitted power.

Claim 25

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis, wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, an eddy current device positioned somewhere along the longitudinal axis of said resonating bar, further including, means for supplying a constant magnetic field having components substantially perpendicular to the components of vibrational motion being measured, a body of high permeability positioned contiguous to a small area of said body surface, first coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being wound about said high-permeability body, the axis of said winding being parallel to one component of motion being measured, second coil means for sensing a varying magnetic field caused by said self-induced eddy currents on the vibrating surface, said coil be wound about said high-permeability body, the axis of said winding being perpendicular to the axis of said first coil means and being parallel to another component of motion being measured, first means electrically coupled to said first coil means for measuring the voltage induced by said varying magnetic field, and second means electrically coupled to said second coil means for measuring the voltage induced by said varying magnetic field, whereby the measurements of both coil means are used to calculate the transmitted power.

Claim 26

A meter for measuring the power transmitted by an acoustic signal to a dissipative load coupled to one end of a bar having a longitudinal axis, wherein said acoustic signal causes said bar to longitudinally vibrate, comprising, an eddy current device positioned somewhere along the longitudinal axis of said resonating bar, further including, means for supplying a constant magnetic field having components substantially perpendicular to the components of vibrational motion being measured, a body of high permeability positioned contiguous to a small area of said body surface, first coil means for sensing a varying magnetic field caused by self-induced eddy currents on the vibrating surface, said coil being wound about said high-permeability body, the axis of said winding being parallel to one component of motion being measured, second coil means for sensing a varying magnetic field caused by said self-induced eddy currents on the vibrating surface, said coil be wound about said high-permeability body, the axis of said winding being perpendicular to the axis of said first coil means and being parallel to another component of motion being measured, first means electrically coupled to said first coil means for measuring the voltage induced by said varying magnetic field, and second means electrically coupled to said second coil means for measuring the voltage induced by said varying magnetic field, whereby the measurements of both coil means are used to calculate the transmitted power.

Claim 27

A meter in accordance with claim 17, wherein the eddy current device is positioned at a loop of longitudinal motion.

Claim 28

A meter in accordance with claim 17, wherein the eddy current device is positioned at a node of longitudinal motion.