US4646000A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring soil salinity
Assignee: YSI Inc
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Filing: 1984-11-08
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Granted: 1987-02-24
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Expires: 2004-11-08
Abstract
Abstract A method for measuring soil salinity measures the low frequency permittivity of a soil sample at one or more frequencies below 2 megahertz and determines the salinity of the soil sample based on the measured real part of the permittivity. Apparatus for performing the method comprises a soil sample holder for laboratory measurements or a four electrode array for measuring soil salinity in situ. An electrical circuit measures the low frequency permittivity of the soil sample and converts the measured permittivity to the salinity of the soil sample. The salinity conversion can be performed by a read-only memory or a computer with the output being registered by display on a digital or analog display or storage in a data memory.
Inventors
- 👤 Robert H. Wills
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:20
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R27/26; G01R27/2617; G01R27/2635; G01N; G01N27/00; G01N27/02; G01N27/22; G01N27/223; G01N33/00; G01N33/24
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
53 words
A method for measuring soil salinity comprising the following steps: measuring the real part of the low frequency electric permittivity (ε') of a soil sample; determining the salinity of said soil sample based on the measured real part of the low frequency electric permittivity (ε'); and registering the salinity of said soil sample.
Claim 2
Independent Claim
53 words
A method for measuring soil salinity comprising the following steps: measuring the real part of the low frequency electric permittivity (ε') of a soil sample; determining the salinity of said soil sample based on the measured real part of the low frequency electric permittivity (ε'); and registering the salinity of said soil sample.
Claim 3
Dependent Claim
31 words
A method for measuring soil salinity as claimed in claim 1 wherein the step of measuring the low frequency electric permittivity is performed at one or more frequencies below 2 megahertz.
Claim 4
Dependent Claim
52 words
A method for measuring soil salinity as claimed in claim 2 further comprising the step of measuring the moisture content of said soil sample and wherein the step of determining the salinity of said soil sample is based on the measured electric permittivity and the measured moisture content of said soil sample.
Claim 5
Dependent Claim
49 words
A method of measuring soil salinity as claimed in claim 3 further comprising determining the soil type wherein the step of determining the salinity of said soil sample comprises calculating the extract conductivity based on the soil type, measured electric permittivity and measured moisture content of said soil sample.
Claim 6
Dependent Claim
27 words
A method for measuring soil salinity as claimed in claim 4 wherein the step of registering the salinity of said soil sample comprises displaying the determined salinity.
Claim 7
Dependent Claim
27 words
A method for measuring soil salinity as claimed in claim 4 wherein the step of registering the salinity of said soil sample comprises storing the determined salinity.
Claim 8
Dependent Claim
95 words
Apparatus for measuring soil salinity comprising: sample means for engaging a soil sample the salinity of which is to be determined; circuit means connected to said sample means for measuring the real part of the low frequency electric permittivity (ε') of said soil sample and for generating electric permittivity signals representative thereof; conversion means connected to said circuit means and responsive to said permittivity signals for generating salinity signals representative of the salinity of said soil sample; and salinity registration means for registering the salinity of said soil sample in response to said salinity signals.
Claim 9
Dependent Claim
95 words
Apparatus for measuring soil salinity comprising: sample means for engaging a soil sample the salinity of which is to be determined; circuit means connected to said sample means for measuring the real part of the low frequency electric permittivity (ε') of said soil sample and for generating electric permittivity signals representative thereof; conversion means connected to said circuit means and responsive to said permittivity signals for generating salinity signals representative of the salinity of said soil sample; and salinity registration means for registering the salinity of said soil sample in response to said salinity signals.
Claim 10
Dependent Claim
24 words
Apparatus as claimed in claim 7 wherein said low frequency electric permittivity is determined at one or more frequencies at or below 2 megahertz.
Claim 11
Dependent Claim
30 words
Apparatus as claimed in claim 8 wherein said conversion means is further responsive to moisture signals representative of the moisture content of said soil sample for generating said salinity signals.
Claim 12
Dependent Claim
18 words
Apparatus as claimed in claim 9 wherein said moisture signals are generated by the operator of said apparatus.
Claim 13
Dependent Claim
26 words
Apparatus as claimed in claim 9 wherein said circuit means further provides for measuring the moisture content of said soil sample and generating said moisture signals.
Claim 14
Dependent Claim
14 words
Apparatus as claimed in claim 9 wherein said conversion means comprises a read-only memory.
Claim 15
Dependent Claim
13 words
Apparatus as claimed in claim 9 wherein said conversion means comprises a computer.
Claim 16
Dependent Claim
14 words
Apparatus as claimed in claim 9 wherein said salinity registration means comprises a display.
Claim 17
Dependent Claim
15 words
Apparatus as claimed in claim 9 wherein said salinity registration means comprises a data store.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-23 | 1990-08-25 | 1991-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-23 | 1994-08-25 | 1995-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-23 | 1998-08-25 | 1999-02-24 | $7700.00 | Window Closed / Lapsed |