US3683697A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Temperature compensated gravimeter
Assignee: Individual
•
Filing: 1969-09-12
•
Granted: 1972-08-15
•
Expires: 1989-09-12
Abstract
Abstract In a gravimeter, the gravity-responsive mass-and-spring system which responds to changes in gravity exhibits a dependence of its response upon changes in temperature. For compensating such temperature dependence, an electrically controllable force transmitter, preferably of the electromagnetic type, is connected with the mass of the gravimeter system to impose a corrective force thereupon. The force transmitter is controlled by an electric device which comprises temperature sensor means mounted in the housing which accommodates the gravimeter system. The sensor means operate to vary the corrective force in the sense required for minimizing or obviating the temperature dependence of the response characteristic.
Inventors
- 👤 Eberhard Thebis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:09
CPC Classifications
G; G01; G01V; G01V7/00; G01V7/08
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
253 words
A gravimeter having a housing, a mass-and-spring gravimeter system mounted in said housing and having a temperature-dependent characteristic of response to changes in gravity, indicating means responsive to displacement of the mass of said mass-andspring system for indication of forces acting upon said system, in combination with an electrically controllable force transmitter for imposing corrective force upon said gravimeter system, an electric control device connected to said force transmitter and having temperature-responsive sensor means in said housing for controlling said corrective force to compensate for said temperature dependence of said response characteristic, said force transmitter comprising electrically controllable field means having an electric circuit for excitation of a force field, and the mass of said system having a part located in the field of said field means for causing said corrective force to act between said part and said field means, said field means comprising a permanent magnet fixedly mounted in said housing, said part of said mass including a coil carrier movable in the field of said magnet and joined with said gravimeter mass, said electric circuit comprising a coil mounted on said carrier in said field, and a coil circuit connecting said coil to said control device, said force transmitter comprising a second coil mounted on said carrier in the field of said magnet, electric control means having sensor means responsive to deflection of said mass and being connected to said second coil and to said indicating means for energizing said second coil to magnetically balance gravitational deflection of said system.
Claim 2
Dependent Claim
253 words
A gravimeter having a housing, a mass-and-spring gravimeter system mounted in said housing and having a temperature-dependent characteristic of response to changes in gravity, indicating means responsive to displacement of the mass of said mass-andspring system for indication of forces acting upon said system, in combination with an electrically controllable force transmitter for imposing corrective force upon said gravimeter system, an electric control device connected to said force transmitter and having temperature-responsive sensor means in said housing for controlling said corrective force to compensate for said temperature dependence of said response characteristic, said force transmitter comprising electrically controllable field means having an electric circuit for excitation of a force field, and the mass of said system having a part located in the field of said field means for causing said corrective force to act between said part and said field means, said field means comprising a permanent magnet fixedly mounted in said housing, said part of said mass including a coil carrier movable in the field of said magnet and joined with said gravimeter mass, said electric circuit comprising a coil mounted on said carrier in said field, and a coil circuit connecting said coil to said control device, said force transmitter comprising a second coil mounted on said carrier in the field of said magnet, electric control means having sensor means responsive to deflection of said mass and being connected to said second coil and to said indicating means for energizing said second coil to magnetically balance gravitational deflection of said system.
Claim 3
Dependent Claim
60 words
In a gravimeter according to claim 1, said control device comprising a bridge network having resistive bridge branches, said sensor means comprising two temperature-responsive resistors connected in two opposite ones of said bridge branches, said coil circuit being connected to the output diagonal of said bridge network, and a source of adjustable constant voltage connected to the bridge input diagonal.
Claim 4
Dependent Claim
31 words
In a gravimeter according to claim 2, said control device comprising further temperature-responsive resistance means connected with said input diagonal for varying the bridge input voltage in dependence upon temperature changes.
Claim 5
Dependent Claim
20 words
In a gravimeter according to claim 3, said further tempeRature-responsive resistance means being connected in series with said voltage source.
Claim 6
Dependent Claim
21 words
In a gravimeter according to claim 3, said further temperature-responsive resistance means being connected in parallel relation to said voltage source.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |