US4383221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water resistivity sensor
Assignee: IP HOLDING COMPANY A DE CORP
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Filing: 1980-10-21
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Granted: 1983-05-10
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Expires: 2000-10-21
Abstract
Abstract A compact, battery-powered water resistivity sensor measures the resistivity of water, sequentially compares the measured resistivity to a plurality of predetermined resistivities, and numerically displays that one of the plurality of predetermined resistivities approximating the measured resistivity. Preferably, the pair of electrodes consists of a pair of printed circuit electrodes disposed conveniently on the end face of an insulating nut extending, in fluid-tight fashion, into the tank of water. The sensor is powered by a battery, and includes circuitry for interrupting the supply of battery power to various circuit elements, the functions of which elements are no longer needed once the water resistivity is determined by the sensor. The sensor also includes temperature-sensitive compensation means responsive to changes in the water temperature for varying an input signal provided to the electrodes. Finally, the sensor includes a low battery condition detection means responsive to the low battery condition for displaying a corresponding low battery indicator.
Inventors
- 👤 Kenneth H. Morey
- 👤 Steven C. Dark
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 16:06
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/02; G01N27/04; G01N27/06; G01N27/07
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
136 words
A water resistivity sensor for indicating the resistivity of water comprising: electrode means for generating a signal proportional to the resistivity of the water; circuit means for processing said signal from said electrode means and issuing an output signal corresponding to the resistivity of the water, wherein said electrode means comprises a reference circuit sequentially providing successive voltage values corresponding to successive, resistivity values, and a voltage comparator connected to said electrode means and to said reference circuit for comparing said signal from said electrode means to each successive voltage value so as to determine that one of said successive voltage values approximates said signal from said electrode means, whereby the resistivity of the water is determined; and display means responsive to said output signal of said circuit means for displaying the resistivity of the water.
Claim 2
Dependent Claim
136 words
A water resistivity sensor for indicating the resistivity of water comprising: electrode means for generating a signal proportional to the resistivity of the water; circuit means for processing said signal from said electrode means and issuing an output signal corresponding to the resistivity of the water, wherein said electrode means comprises a reference circuit sequentially providing successive voltage values corresponding to successive, resistivity values, and a voltage comparator connected to said electrode means and to said reference circuit for comparing said signal from said electrode means to each successive voltage value so as to determine that one of said successive voltage values approximates said signal from said electrode means, whereby the resistivity of the water is determined; and display means responsive to said output signal of said circuit means for displaying the resistivity of the water.
Claim 3
Dependent Claim
148 words
A sensor unit for measuring the resistivity of water contained in a tank comprising: a pair of electrodes generating a signal proportional to the resistivity of the water; electrode carrying means for carrying said pair of electrodes through said tank so as to cause said electrodes to contact the water; circuit means in communication with said pair of electrodes, said circuit means comprising a reference circuit sequentially providing successive voltage values corresponding to successive resistivity values, and a voltage comparator connected to said pair of electrodes and to said reference circuit for comparing said signal from said pair of electrodes to each said successive voltage values so as to determine that one of said successive voltage values approximates said signal from said pair of electrodes, whereby the resistivity of the water is determined; and display means connected to said circuit means for displaying the resistivity of the water.
Claim 4
Dependent Claim
148 words
A sensor unit for measuring the resistivity of water contained in a tank comprising: a pair of electrodes generating a signal proportional to the resistivity of the water; electrode carrying means for carrying said pair of electrodes through said tank so as to cause said electrodes to contact the water; circuit means in communication with said pair of electrodes, said circuit means comprising a reference circuit sequentially providing successive voltage values corresponding to successive resistivity values, and a voltage comparator connected to said pair of electrodes and to said reference circuit for comparing said signal from said pair of electrodes to each said successive voltage values so as to determine that one of said successive voltage values approximates said signal from said pair of electrodes, whereby the resistivity of the water is determined; and display means connected to said circuit means for displaying the resistivity of the water.
Claim 5
Dependent Claim
169 words
A water resistivity sensor for indicating the resistivity of water comprising: generator means for generating a signal; printed circuit electrode means connected to said generator means and being positioned in said water for receiving said signal and providing an output signal proportional to the resistivity of said water; circuit means for processing said output signal of said printed circuit electrode means and issuing an output signal corresponding to the resistivity of said water, wherein said circuit means comprises a reference circuit sequentially providing successive voltage values corresponding to respective successive resistivity values, and a voltage comparator connected to said electrode means and to said reference circuit for comparing said output signal of said electrode means to each said respective successive voltage value so as to determine that one of said successive voltage values approximates said output signal of said electrode means, whereby to determine said resistivity of said water; and display means responsive to said output signal of said circuit means for numerically displaying said resistivity of said water.
Claim 6
Dependent Claim
169 words
A water resistivity sensor for indicating the resistivity of water comprising: generator means for generating a signal; printed circuit electrode means connected to said generator means and being positioned in said water for receiving said signal and providing an output signal proportional to the resistivity of said water; circuit means for processing said output signal of said printed circuit electrode means and issuing an output signal corresponding to the resistivity of said water, wherein said circuit means comprises a reference circuit sequentially providing successive voltage values corresponding to respective successive resistivity values, and a voltage comparator connected to said electrode means and to said reference circuit for comparing said output signal of said electrode means to each said respective successive voltage value so as to determine that one of said successive voltage values approximates said output signal of said electrode means, whereby to determine said resistivity of said water; and display means responsive to said output signal of said circuit means for numerically displaying said resistivity of said water.
Claim 7
Dependent Claim
101 words
The sensor of claim 3, wherein said circuit means comprises a counter responsive to provision of said successive voltage values by said reference circuit for counting through respective successive count states to develop corresponding successive count outputs, said display means comprising a decoder responsive to that one of said successive count outputs corresponding to said one of said successive voltage values determined by said comparator for deriving a minimum number of display driving signals for displaying that one of said respective successive resistivity values corresponding to said one of said successive voltage values approximating said output signal of said electrode means.
Claim 8
Dependent Claim
42 words
The sensor of claim 3, said generator means comprising temperature-sensitive compensation means responsive to the temperature of said water for adjusting said signal provided by said generator means to said electrode means in accordance therewith, whereby to compensate the water temperature changes.
Claim 9
Dependent Claim
51 words
The sensor of claim 3, further comprising a battery, and low battery detector means connected to said battery for detecting a low battery condition, said display means being connected to said low battery detector means and responsive to detection of said low battery condition for displaying a low battery indication signal.
Claim 10
Dependent Claim
50 words
The sensor of claim 3, further comprising battery means for supplying power to said generator means, said electrode means, said circuit means and said display means, and interruption means for interrupting said power provided by said battery means once said resistivity of said water is determined by said circuit means.
Claim 11
Dependent Claim
104 words
The sensor of claim 1, wherein said circuit means comprises a counter responsive to said provision of said successive voltage values of said reference circuit for counting through a corresponding number of count states to develop successive respective count outputs, said display means comprising a display drive circuit responsive to that one of said successive count outputs corresponding to said one of said successive voltage values determined by said comparator for issuing a minimum number of drive signals for displaying that one of said respective successive resistivity values corresponding to that one of said successive voltage values approximating said signal from said electrode means.
Claim 12
Dependent Claim
56 words
The sensor of claim 1, further comprising temperature-sensitive compensation means connected between said circuit means and said electrode means, and responsive to a change in the temperature of said water for adjusting said input signal provided by said circuit means to said electrode means, whereby to compensate for said change in the temperature of said water.
Claim 13
Dependent Claim
42 words
The sensor of claim 1, further comprising a battery, and low battery detection means connected to said battery for determining a low battery condition thereof, said display means being connected to said low battery detection means for displaying a low battery indication.
Claim 14
Dependent Claim
40 words
The sensor of claim 1, further comprising battery means for supplying power to said circuit means, and interruption means for interrupting said power supplied by said battery means once said resistivity of said water is determined by said circuit means.
Claim 15
Dependent Claim
26 words
The unit of claim 2, wherein said pair of electrodes comprises a pair of printed circuit electrodes arranged in spatical relationship with respect to each other.
Claim 16
Dependent Claim
44 words
The unit of claim 2, wherein said electrode carrying means comprises a threaded insulating nut extending through said tank to the interior thereof, said threaded insulating nut having an end face extending into the interior of said tank and carrying said pair of electrodes.
Claim 17
Dependent Claim
14 words
The unit of claim 12, wherein said circuit means comprises a printed circuit board.
Claim 18
Dependent Claim
52 words
The unit of claim 12, wherein said circuit means provides an input signal to one of said pair of electrodes, said unit further comprising temperature-sensitive compensation means responsive to change in the temperature of said water for adjustably varying said input signal provided by said circuit means to said pair of electrodes.
Claim 19
Dependent Claim
51 words
The unit of claim 12, wherein said sensor unit is powered by a battery, said unit including low battery detection means connected to said battery for detecting a low battery condition of said battery, said display means being connected to said low battery detection means for displaying a low battery indicator.
Claim 20
Dependent Claim
39 words
The unit of claim 12, wherein said electrode carrying means comprises an insulating nut having an end face which is recessed, said pair of electrodes comprising printed circuit electrodes positioned in said recessed end face of said insulating nut.
Claim 21
Dependent Claim
52 words
The unit of claim 12, comprising battery means for powering said circuit means and said display means, and interruption means connected to said battery and to said circuit means for interrupting said power supply to said circuit means and said display means when said circuit means determines said resistivity of said water.
Claim 22
Dependent Claim
111 words
The unit of claim 2, said circuit means comprising a counter responsive to said provision of said successive voltage values by said reference circuit for counting through a plurality of count states corresponding, respectively, to said successive voltage values so as to develop corresponding respective count outputs, said display means comprising display driving circuitry responsive to that one of said successive count outputs corresponding to said one of said successive voltage values determined by said comparator for deriving a minimum number of driving signals for displaying that one of said respective successive resistivity values corresponding to said one of said successive voltage values approximating said output signal of said electrode means.
Claim 23
Dependent Claim
14 words
The unit of claim 2, wherein said circuit means comprises a printed circuit board.
Claim 24
Dependent Claim
39 words
The unit of claim 2, wherein said electrode carrying means comprises an insulating nut having an end face which is recessed, said pair of electrodes comprising printed circuit electrodes positioned in said recessed end face of said insulating nut.
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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) | 1986-05-09 | 1986-11-08 | 1987-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-05-09 | 1990-11-08 | 1991-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-05-09 | 1994-11-08 | 1995-05-10 | $7700.00 | Window Closed / Lapsed |