Patent US1696311A successfully refreshed from Google Patents.
Patent US4251775A successfully refreshed from Google Patents.
← Back to Patent Explorer
US4251775A Expired / Lapsed US ⏱️ 0.0 years remaining

Ion flux density probe

Assignee: Santek Inc
•
Filing: 1979-03-01
•
Granted: 1981-02-17
•
Expires: 1999-03-01
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A probe operable in conjunction with an electrometer having a high input impedance to provide an instrument for measuring air ion flux density. The probe structure is such that its presence in the atmosphere in which a measurement is being carried out will not give rise to perturbations in the localized electric field and therefore has no perceptible effect on the accuracy of measurement. The probe is constituted by a metal target to which the ions give up their charge, the target being supported at the end of a barrel of dielectric material by a conductor attached thereto and extending axially through the barrel to a contact at the rear of the barrel which is connected to the line of a shielded coaxial cable which couples the target to the input terminal of a grounded electrometer, the shield of the cable also being grounded. The surface of the barrel is coated with a layer of semi-conductive material that makes contact at the lower end of the barrel with the grounded cable shield. The semi-conductive layer on the barrel surrounding the target conductor therein provides a controlled leakage path extending between the target and the grounded cable shield that approximates the characteristics of the atmosphere and the input impedance of the electrometer whereby the presence of the probe in the atmosphere introduces substantially no discontinuity in the localized electric field.

Inventors

  • 👤 Thomas J. Michel

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 04:42
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/08; G01N; G01N27/00; G01N27/62

Claims Analysis

Total Claims: 12
Claim 1
Independent Claim 197 words
An instrument for measuring gas ion flux density constituted by a probe placeable in the atmosphere to be tested and coupled by a coaxial cable having an inner line and an outer shield to the input terminal of a current-indicating device having a high input impedance, said shield and said device being grounded, said probe comprising: A. a conductive target, to which ions give up their charge, supported at one end of a barrel formed of dielectric material, said target being connected by a conductor passing through said barrel to a terminal at the other end of the barrel making electrical contact with the inner line of said cable; and B. a semi-conductive layer coated on the surface of said barrel and extending to the lower end thereof to effect a connection with the shield of said grounded cable, said layer providing a controlled leakage path extending between the target and the shield that approximates the characteristics of the atmosphere and the input impedance of the device, whereby the presence of the probe in the atmosphere gives rise to no perturbations in the localized electric field and therefore has no perceptible effect on the accuracy of measurement.
Claim 2
Dependent Claim 197 words
An instrument for measuring gas ion flux density constituted by a probe placeable in the atmosphere to be tested and coupled by a coaxial cable having an inner line and an outer shield to the input terminal of a current-indicating device having a high input impedance, said shield and said device being grounded, said probe comprising: A. a conductive target, to which ions give up their charge, supported at one end of a barrel formed of dielectric material, said target being connected by a conductor passing through said barrel to a terminal at the other end of the barrel making electrical contact with the inner line of said cable; and B. a semi-conductive layer coated on the surface of said barrel and extending to the lower end thereof to effect a connection with the shield of said grounded cable, said layer providing a controlled leakage path extending between the target and the shield that approximates the characteristics of the atmosphere and the input impedance of the device, whereby the presence of the probe in the atmosphere gives rise to no perturbations in the localized electric field and therefore has no perceptible effect on the accuracy of measurement.
Claim 3
Dependent Claim 26 words
An instrument as set forth in claim 1, wherein said target is laminated to an insulating base which rests on the one end of the barrel.
Claim 4
Dependent Claim 18 words
An instrument as set forth in claim 1, in which said target is formed of a copper-based metal.
Claim 5
Dependent Claim 25 words
An instrument as set forth in claim 1, wherein said semi-conductive layer is formed by a dispersion of conductive particles in an electrically insulating matrix.
Claim 6
Dependent Claim 19 words
An instrument as set forth in claim 4, wherein said matrix is of material compatible with the barrel material.
Claim 7
Dependent Claim 15 words
An instrument as set forth in claim 5, wherein said barrel material is an acrylic.
Claim 8
Dependent Claim 119 words
An instrument as set forth in claim 1, wherein said target conductor is joined to the inner tubular connector of a jack socketed in a bore in the other end of the barrel, said jack having a cylindrical outer connector whose diameter is such that an annular space is formed between the lower end thereof and the wall of the bore, said cable terminating in a coupler having a plug connected to the inner line and inserted in the inner connector of the jack and having a concentric ring which is inserted in said space and joined to the outer connector of the jack, said ring being connected to said shield and making physical contact with said semi-conductive layer.
Claim 9
Dependent Claim 14 words
An instrument as set forth in claim 1, wherein said device is an electrometer.
Claim 10
Dependent Claim 26 words
An instrument as set forth in claim 8, wherein said electrometer has a polarity-reversing switch which renders said electrometer selectively responsive to negative or positive ions.
Claim 11
Dependent Claim 16 words
An instrument as set forth in claim 8, wherein said electrometer has an ion-flux density indicator.
Claim 12
Dependent Claim 44 words
An instrument as set forth in claim 1, wherein said target is recessed within said one end of the barrel and its edge is surrounded and shielded by said semi-conductive layer, whereby said probe has directional characteristics determined by the depth of the recess.

References Cited (Backward Citations)

US3445757A Cited
US3559049A Cited
US3864628A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1984-02-17 1984-08-18 1985-02-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1988-02-17 1988-08-18 1989-02-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1992-02-17 1992-08-18 1993-02-17 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag