Method for measuring a rotational velocity and a gyrometer for the practical application of said method |
|||||||
| 申请号 | US39441573 | 申请日 | 1973-09-05 | 公开(公告)号 | US3909706A | 公开(公告)日 | 1975-09-30 |
| 申请人 | COMMISSARIAT ENERGIE ATOMIQUE; | 发明人 | GRESCINI JEAN; GLENAT HENRI; SALVI ANTEINE; | ||||
| 摘要 | A homogeneous and steady directing magnetic field is produced in the direction about which a rotational velocity is to be measured. An electrical signal is delivered by a nuclear magnetic resonance magnetometer probe which is placed in the magnetic field and rotates at said velocity. The difference between the frequency of the signal and the detected frequency of resonance or reference frequency serves to determine the value of rotational velocity. | ||||||
| 权利要求 | 1. A gyrometer comprising: means for producing a homogeneous, steady directing magnetic field Ho in the direction about which a rotational velocity is to be measured; means including a magnetic resonant material disposed to rotate in said field at said velocity for generating during rotation a first electrical signal having frequency omega , where omega equals the Larmor frequency of said material gamma Ho'', where Ho'' equals Ho plus any external perturbational field components; means disposed to rotate in said field for generating during rotation a second electrical signal having frequency omega '', where omega '' equals gamma Ho'' plus said rotational velocity; and means for measuring the difference between the frequency omega '' of said second signal and the frequency omega of said first signal. 2. A gyrometer according to claim 1 wherein said means for generating a first electrical signal comprises a nuclear spin coupling oscillator including a first isotropic magnetometer probe for developing a nuclear magnetic resonance signal; said probe including two collecting windings having a common axis parallel to said directing field for collecting said nuclear magnetic resonance signal. 3. A gyrometer according to claim 2 wherein said means for generating a second electrical signal comprises a second magnetometer probe including at least one coil, said coil having its axis perpendicular to said directing field. 4. The gyrometer of claim 2 wherein said means for generating a second electrical signal comprises at least one coil having an axis at right angles to said directing field and coupled inductively to said oscillator; and means for amplifying the voltage developed by said coil. 5. A gyrometer according to claim 4 wherein said coil is divided into two half-coils placed symmetrically on each side of said probe and connected to add the useful signals. 6. A gyrometer according to claim 2 wherein said first magnetometer probe is of the dynamic polyarization type and includes: two samples each composed of a solvent which possesses a nuclear spin and a paramagnetic substance including a chemical radical dissolved in said solvent, said samples being such that, taking into account the directing magnetic field in which they are placed, each sample possesses an electron paramagnetic resonance line at a common frequency, the saturation of said line being intended to produce in the case of one of said samples an increase in the absorption of energy at the nuclear magnetic resonance frequency and in the case of the other sample an emission of energy at said nuclear magnetic resonance frequency; and means for producing a pumping electromagnetic field at said common frequency. 7. A gyrometer according to claim 6, wherein the radical of one of the samples is deuterated TANO dissolved in nonane at a concentration of 10 3 M and in which the radical of the other sample is deuterated DTBN dissolved in a 50% mixture of acetone and water and at a concentration of 10 3 M, the amplitude of the directing field being in the vicinity of 2.5 Oersteds and the common pumping frequency being in the vicinity of 65.5 Mc/s. 8. A gyrometer according to claim 1, wherein said means for producing the directing magnetic field includes an insulating spherical coil former; a spherical coil wound on said former; and a direct-current source for supplying said coil. 9. A gyrometer according to claim 1, wherein said spherical coil is surrounded by a magnetic screen. 10. A gyrometer according to claim 1, wherein said means for producing the directing magnetic field Comprises a regulating winding having an axis parallel to the directing field; a regulating circuit for supplying said regulating winding; said regulating circuit comprising an oscillator at a reference frequency; and a frequency comparator having one input connected to said reference oscillator, a second input connected to said means for generating a first electrical signal of frequency omega ; and an output, said output delivering a correcting signal to said regulating means. 11. A method of measuring the rotational speed of a body in motion about an axis comprising the steps of: attaching to said body in motion a magnetic resonance magnetometer probe; inserting said body and probe into a continuous and homogeneous magnetic field Ho said probe oriented such that a single signal having the single frequency omega '' is produced by said probe; omega '' equalling gamma Ho'' plus the rotational velocity where Ho'' equals Ho plus any external perturbational field components; developing a signal having the frequency omega where omega equals gamma Ho''; and measuring the difference between the frequencies omega and omega '' to derive the value of said speed of rotation. 12. The method of claim 11 wherein said probe operates on the principle of nuclear magnetic resonance. 13. The method of claim 11 wherein said magnetic field is produced by biasing apparatus associated with said probe. 14. The method of claim 11 further including the step of supplying said value as an error signal for use in correcting magnetometer measurements made by a rotating magnetometer carrier. 15. A method of measuring the rotational speed of a body in motion about an axis comprising the steps of: attaching to said body in motion a magnetic resonance magnetometer probe; inserting said body and probe into a continuous and homogeneous magnetic field Ho, said probe being oriented such that a signal having the frequency of magnetic resonance omega is produced by said probe, where omega gamma Ho'' where Ho'' plus any external perturbational field components; developing a signal having the frequency omega '' gamma Ho'' plus the said rotational speed from said probe by induction; and measuring the difference between the frequencies omega and omega '' to derive the value of said rotational speed. 16. A method of measuring the rotational speed of a body in motion about an axis of rotation comprising the steps of: attaching to said body a magnetic resonance magnetometer probe producing a single Larmor frequency; attaching to said body at least one coil, said coil being positioned such that its axis is perpendicular to the axis of rotation and such that said coil is inductively coupled to said probe; inserting said body, prove and said at least one coil into a continuous and homogeneous magnetic field Ho such that the axis of said probe is parallel to the axis of said magnetic field; detecting the electrical signal delivered by said probe wherhe omega gamma Ho'', Ho'' being equal to Ho plus any perturbational fields; detecting the electrical signal omega '' omega plus said rotational speed induced in said at least one coil by said probe; and detecting the difference between the frequency of said signal delivered by said probe and the signal induced in said at least one coil. |
||||||
| 说明书全文 | |||||||
QQ群二维码
意见反馈
意见反馈