IT1245137B - COUPLING FOR LOW CAPACITY MEASUREMENT - Google Patents
COUPLING FOR LOW CAPACITY MEASUREMENTInfo
- Publication number
- IT1245137B IT1245137B ITMI910300A ITMI910300A IT1245137B IT 1245137 B IT1245137 B IT 1245137B IT MI910300 A ITMI910300 A IT MI910300A IT MI910300 A ITMI910300 A IT MI910300A IT 1245137 B IT1245137 B IT 1245137B
- Authority
- IT
- Italy
- Prior art keywords
- oscillator
- coupling
- measured
- capacities
- terminal
- Prior art date
Links
- 230000008878 coupling Effects 0.000 title abstract 3
- 238000010168 coupling process Methods 0.000 title abstract 3
- 238000005859 coupling reaction Methods 0.000 title abstract 3
- 238000005259 measurement Methods 0.000 title abstract 2
- 239000004020 conductor Substances 0.000 abstract 1
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R27/00—Arrangements for measuring resistance, reactance, impedance, or electric characteristics derived therefrom
- G01R27/02—Measuring real or complex resistance, reactance, impedance, or other two-pole characteristics derived therefrom, e.g. time constant
- G01R27/26—Measuring inductance or capacitance; Measuring quality factor, e.g. by using the resonance method; Measuring loss factor; Measuring dielectric constants ; Measuring impedance or related variables
- G01R27/2605—Measuring capacitance
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Measurement Of Resistance Or Impedance (AREA)
Abstract
Accoppiamento per misurare basse capacità (C1, C2, C3), comprendente un oscillatore, quale un oscillatore, quale un oscillatore LC o RC, con frequenza di uscita (fo), funzione della capacità da misurare e collegato fra il terminale d'ingresso (16) dell'oscillatore e la terra. Le capacità (C1, C2, C3) da misurare sono collegate in modo alterno al terminale d'ingresso (16) dell'oscillatore. Ad eccezione della capacità da collegare fra il terminale (16) e la terra per la misura, le altre capacità da misurare sono collegate, con uno dei loro terminali, ad un conduttore (19) comune delle capacità (C1, C2, C3) e, con l'altro, all'uscita dell'inseguitore di tensione. L'ingresso dell'inseguitore è collegato al terminale (16) dell'accoppiamento ad oscillatore. L'inseguitore di tensione comprende un amplificatore operazionale (20), la cui uscita è collegata al proprio ingresso invertente, al quale le capacità (C2, C3) che non vengono misurate sono collegate così che non vi siano differenze di tensione e non sussistano correnti di carica nei loro terminali.Coupling for measuring low capacitances (C1, C2, C3), comprising an oscillator, such as an oscillator, such as an LC or RC oscillator, with output frequency (fo), function of the capacity to be measured and connected between the input terminal ( 16) of the oscillator and the earth. The capacitances (C1, C2, C3) to be measured are alternately connected to the input terminal (16) of the oscillator. With the exception of the capacity to be connected between the terminal (16) and the earth for measurement, the other capacities to be measured are connected, with one of their terminals, to a common conductor (19) of the capacities (C1, C2, C3) and , with the other, at the output of the voltage tracker. The tracker input is connected to the terminal (16) of the oscillator coupling. The voltage tracker includes an operational amplifier (20), the output of which is connected to its inverting input, to which the capacities (C2, C3) that are not measured are connected so that there are no voltage differences and no currents exist of charge in their terminals.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI900592A FI84666C (en) | 1990-02-07 | 1990-02-07 | MAETKOPPLING FOER SMAO KAPASITANSER. |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| ITMI910300A0 ITMI910300A0 (en) | 1991-02-06 |
| ITMI910300A1 ITMI910300A1 (en) | 1992-08-06 |
| IT1245137B true IT1245137B (en) | 1994-09-13 |
Family
ID=8529843
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| ITMI910300A IT1245137B (en) | 1990-02-07 | 1991-02-06 | COUPLING FOR LOW CAPACITY MEASUREMENT |
Country Status (9)
| Country | Link |
|---|---|
| AU (1) | AU6949191A (en) |
| BR (1) | BR9100486A (en) |
| CA (1) | CA2035909A1 (en) |
| DE (1) | DE4103433A1 (en) |
| FI (1) | FI84666C (en) |
| FR (1) | FR2657963A1 (en) |
| GB (1) | GB2242279A (en) |
| IT (1) | IT1245137B (en) |
| ZA (1) | ZA91506B (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19513022C1 (en) * | 1995-04-06 | 1996-08-14 | Siemens Ag | Differential capacitance measuring circuit for pressure sensor |
| DE19625666C1 (en) * | 1996-06-26 | 1998-01-15 | Siemens Ag | Readout shaft and capacitive measuring sensor |
| DE102004006020A1 (en) | 2004-02-06 | 2005-08-25 | E + E Elektronik Ges.M.B.H. | Circuit arrangement for capacitive humidity measurement and method for operating the same |
| US8030949B2 (en) * | 2008-10-31 | 2011-10-04 | Testo Ag | Measurement method for determining moisture content |
| CN101738422B (en) * | 2009-12-23 | 2012-09-05 | 北京宝力马传感技术有限公司 | Humidity measuring device and method |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3886447A (en) * | 1972-05-17 | 1975-05-27 | Iwatsu Electric Co Ltd | Capacitance-voltage converter |
| GB2058364B (en) * | 1979-09-01 | 1983-03-23 | Ferranti Ltd | Capacitance measuring apparatus |
| US4794320A (en) * | 1987-08-10 | 1988-12-27 | Moore Products Co. | Multi-frequency capacitance sensor |
-
1990
- 1990-02-07 FI FI900592A patent/FI84666C/en not_active IP Right Cessation
-
1991
- 1991-01-21 AU AU69491/91A patent/AU6949191A/en not_active Abandoned
- 1991-01-23 ZA ZA91506A patent/ZA91506B/en unknown
- 1991-01-29 GB GB9101869A patent/GB2242279A/en not_active Withdrawn
- 1991-02-05 DE DE4103433A patent/DE4103433A1/en not_active Ceased
- 1991-02-06 BR BR919100486A patent/BR9100486A/en not_active Application Discontinuation
- 1991-02-06 IT ITMI910300A patent/IT1245137B/en active IP Right Grant
- 1991-02-07 CA CA002035909A patent/CA2035909A1/en not_active Abandoned
- 1991-02-07 FR FR9101380A patent/FR2657963A1/en active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| CA2035909A1 (en) | 1991-08-08 |
| GB9101869D0 (en) | 1991-03-13 |
| FI84666B (en) | 1991-09-13 |
| FI900592A7 (en) | 1991-08-08 |
| ZA91506B (en) | 1991-10-30 |
| ITMI910300A0 (en) | 1991-02-06 |
| ITMI910300A1 (en) | 1992-08-06 |
| GB2242279A (en) | 1991-09-25 |
| FI84666C (en) | 1991-12-27 |
| DE4103433A1 (en) | 1991-08-08 |
| AU6949191A (en) | 1991-08-08 |
| FI900592A0 (en) | 1990-02-07 |
| BR9100486A (en) | 1991-10-29 |
| FR2657963A1 (en) | 1991-08-09 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 0001 | Granted | ||
| TA | Fee payment date (situation as of event date), data collected since 19931001 |
Effective date: 19970226 |