Electrical Property Sensing Patents (Class 210/746)
  • Patent number: 4895657
    Abstract: The invention relates to an apparatus for hemodialysis comprising a mixing means which prepares dialysis solution for a dialyzer by mixing concentrate with prepared water. The apparatus comprises a protective system which is independent of the mixing system and which is based on monitoring the conductivity of the dialysis solution. For protection against confusion of the concentrate containers to be connected, in the concentrate intake conduits conductivity measuring cells are additionally provided and the output signals thereof are compared with the desired values of the conductivity of the concentrates of the concentrate containers to be connected. In advantageous manner said conductivity cells are integrated into the concentrate intake conduits in such a way that they serve simultaneously as level sensors for the concentrate in the containers.
    Type: Grant
    Filed: October 5, 1988
    Date of Patent: January 23, 1990
    Assignee: Fresenius AG
    Inventor: Hans-Dietrich Polaschegg
  • Patent number: 4855061
    Abstract: Apparatus for controlling the coagulant dosage rate includes a charge sensor located adjacent a coagulant pump for measuring the net electrical charge on coagulated water before water treatment and a turbidity meter for measuring the effluent turbidity after water treatment. A programmable controller responds to the output signal of the charge sensor to continuously adjust the dosage rate to maintain a set point of charge value in the coagulated water corresponding to a desired effluent turbidity. To maintain calibration of the charge sensor, the controller is also responsive to the output signal of the turbidity meter to adjust the charge value set point as required so that the it corresponds to a preselected effluent turbidity.
    Type: Grant
    Filed: April 26, 1988
    Date of Patent: August 8, 1989
    Assignee: CPC Engineering Corporation
    Inventor: Arnold D. Martin
  • Patent number: 4830757
    Abstract: A water quality monitor computer (10) repeatedly accesses transducers (12) which monitor physical properties of a water system, such as total dissolved solids, pH, and the like. The water quality monitor computer determines from the monitored water conditions when bleeding or the addition of water treatment chemicals is required. An energy and water management computer (20) periodically accesses the water quality computer and operates valves and pumps (22) to bleed the system or add chemicals, as is appropriate. The management computer further monitors the quantity of chemical supplies on hand with chemical inventory transducers (24), the amount of electrical energy consumed with kilowatt transducer (28) and the like. The energy and water management computer controls energy usage and stores energy and chemical consumption data in a memory (40).
    Type: Grant
    Filed: October 13, 1987
    Date of Patent: May 16, 1989
    Assignee: The Mogul Corporation
    Inventors: John T. Lynch, Hadley M. Hurford, Jr.
  • Patent number: 4820425
    Abstract: A capacitance liquid sensor for a filtration station for a robotic liquid analyzer detects conclusion of the fluid filtration step by return of the capacitance in the station to its original value.
    Type: Grant
    Filed: January 28, 1988
    Date of Patent: April 11, 1989
    Assignee: Shell Oil Company
    Inventor: Alexander Telfer
  • Patent number: 4818412
    Abstract: An improved apparatus and process for feeding hypochlorite solution from a source of the solution to a device for removing impurities from water in a water treatment system is disclosed. The improvement comprises a first means for continuously measuring the oxidation/reduction potential of the effluent water of the device, and a second means operatively connected to the first means and the pump means continuously controlling the feed-rate of the pump means in response to the measured oxidation/reduction potential of the effluent water, thereby maintaining a predetermined oxidation/reduction potential in the effluent water of the device.
    Type: Grant
    Filed: April 1, 1986
    Date of Patent: April 4, 1989
    Assignee: Betz Laboratories, Inc.
    Inventor: John T. Conlan
  • Patent number: 4802989
    Abstract: A system for purifying dye comprising a means for producing a dye solution and a means for treating the dye solution which captures metal ions in said dye solution by carrying out ion-exchange separation.
    Type: Grant
    Filed: October 29, 1986
    Date of Patent: February 7, 1989
    Assignee: Canon Kabushiki Kaisha
    Inventors: Masahiro Haruta, Kunitaka Ozawa, Takashi Hamamoto
  • Patent number: 4767511
    Abstract: System for automatic control of chlorine content and pH in swimming pools. This system includes an electrolytic cell for generation of chlorine and caustic soda as needed, and an acid supply system for adding hydrochloric acid to the pool as required. Generation of chlorine and addition of acid are controlled automatically in response to sensed oxidation-reduction potential (ORP) and pH of the swimming pool water. The sensors for this purpose may be placed in a conventional pool recirculation line, and chlorine, caustic soda (which is co-produced with chlorine) and hydrochloric acid may be added to the pool via the recirculation line.The electrolytic cell has a porous separator dividing the cell into anolyte and catholyte compartments. The latter is operated at a slightly higher pressure than the former. Chlorine generated in the cell is separated from spent brine, which is recirculated back to a brine tank where it is resaturated. The system may include a timer.
    Type: Grant
    Filed: March 18, 1987
    Date of Patent: August 30, 1988
    Inventor: Pedro J. Aragon
  • Patent number: 4752401
    Abstract: A method and apparatus are disclosed for treating water, either potable water or a recirculated body of water, in which the water flows through a passage around and in direct contact with the surface of the germicidal ultraviolet lamp and in direct contact with at least one ozone producing ultraviolet lamp, whereby dissolved oxygen in the water is directly converted into ozone dispersed in said flowing water. The water, when part of a recirculated flow as in treatment of pool or spa water, also flows in contact with a predominantly copper element having an extended surface, whereby ions of the copper are taken up in the water. The copper element preferably is a pair of spaced apart copper electrodes across which is applied an electrical potential by a control which maintains a constant current and thus regulates release of copper ions into the water for inhibiting growth of algae. The UV lamps are subjected to ultrasonic energy which will loosen particles tending to cling deposit on the lamp surface.
    Type: Grant
    Filed: February 26, 1987
    Date of Patent: June 21, 1988
    Assignee: Safe Water Systems International, Inc.
    Inventor: Willem J. Bodenstein
  • Patent number: 4707272
    Abstract: A level measuring sensor is arranged at the start of the straining zone in the perforated belt press and this in particular measures the level change and then regulates the flocculant inflow. In order that the level in the straining zone is stabilized, the perforated belt press must operate in the overflocculation zone. If the flocculant inflow is reduced to the technically possible operating limit, the dry substance content of the filter cake has an optimum value. Thus, the optimization of the control of the operation of the perforated belt press can be reduced to a relatively simple measurement of a level or the time changed thereto.
    Type: Grant
    Filed: March 14, 1986
    Date of Patent: November 17, 1987
    Assignee: Von Roll AG
    Inventor: Francois Kistler
  • Patent number: 4695385
    Abstract: A dialysis reuse system for cleansing, sterilizing and testing a hemodialysis machine and its associated dialyzer and blood tubing set. The reuse control device automatically controls either the selected reuse cycle or dialyzer test cycle as desired. In the reuse cycle a proper solution of bleach, rinse water and formaldehyde disinfectant is flushed through the system for a prearranged time period and in proper sequence to completely cleanse and disinfect the entire dialysis system including the dialyzer and blood lines. At the end of the cycle, the system is isolated, leaving the disinfectant solution intact within the system to prevent bacteria growth and contamination. In the dialyzer test cycle, a dialyzer clearance test is automatically performed using the associated hemodialysis machine to test the condition of the dialyzer membrane prior to patient treatment.
    Type: Grant
    Filed: April 29, 1985
    Date of Patent: September 22, 1987
    Assignee: Colorado Medical, Inc.
    Inventor: James T. Boag
  • Patent number: 4655932
    Abstract: There is disclosed a novel apparatus and process for the complete dewatering of sludge containing hazardous and toxic materials, the stabilization of pathogens and microorganisms contained in the sludge and the disintegration and volume reduction of the resultant solids including a blending chamber for the blending of sludge and a predetermined amount of electrolyte, the partial dewatering of the sludge and electrolyte in a filter unit, the adjustment of the resultant filter cake to a desired thickness and the measurement of the conductivity of the filter cake and the transporting of the filter cake to a disintegration chamber where the filter cake is introduced to an automatically-adjustable source of electrical energy reducing the filter cake to particulate solids and where the filter cake conductivity measurements are communicated to the blending station and the source of electrical energy for the automatic adjustment of same.
    Type: Grant
    Filed: February 10, 1986
    Date of Patent: April 7, 1987
    Inventor: Don Roslonski
  • Patent number: 4654147
    Abstract: An automated control system for maintaining a supply of dissolved oxygen (DO) within a given range in each of a given plurality of pools for treating sewerage, farming fish, or the like, and energizing an alarm system (148 FIG. 1) which, when energized, will warn designated persons of the failure to maintain the amout of D.O. within the given range in a particular pool and with each pool comprising a first sensor for sensing the amount of D.O. in each pool, a settable indicator (146) for detecting, respectively, when the amount of D.O. drops below a first threshold and when the amount of D.O. drops below a second threshold, with both the first and second thresholds being selectively determinable by setting the indicator. Also provided is a communication link for transmitting the amount of D.O. to the indicators, a second sensor responsive to the amount of D.O. dropping below the first threshold (146) to energize the pool aerator (258 FIG. 3) to increase the amount of D.O.
    Type: Grant
    Filed: March 17, 1986
    Date of Patent: March 31, 1987
    Assignee: Automated Commercial Controls, Inc.
    Inventor: William A. Bagley
  • Patent number: 4624742
    Abstract: A method and apparatus is provided for measuring the present and ongoing performance of paper pulp brown stock washers. Black liquor carryover within a washer mat past wash liquor application showers is quantified by determination of and correlation with the mat liquor specific conductivity.
    Type: Grant
    Filed: February 27, 1984
    Date of Patent: November 25, 1986
    Assignee: Westvaco Corporation
    Inventors: Edward P. Klein, Thomas M. Neider
  • Patent number: 4623469
    Abstract: A method for treating liquid and semi-liquid wastes to render them fit for ultimate disposal, by first determining the ionic charge of the waste counter ions. An appropriate suspension of emulsified asphalt particles is then selected having an opposite particle charge to the ionic charge of the waste counter ions. The waste is then mixed with the selected suspension of emulsified asphalt particles at ambient temperature in an amount sufficient to react with the waste counter ions and coalesce into a hydrophobic mass.
    Type: Grant
    Filed: February 26, 1985
    Date of Patent: November 18, 1986
    Assignee: Chem-Technics, Inc.
    Inventor: Jesse R. Conner
  • Patent number: 4614594
    Abstract: The basic water and sediment (BS&W) system compares a wet stream to a dry stream of the same oil in two electrical capacitance cells. A numerical zero offset is employed in the comparison to compensate for voltage output differences between the cells. The dry cell builds a small increase in its inherent offset from the wet cell because of its lower flow rate, which buildup is swept away when the wet fluid is run through both cells at a higher flow rate to determine the zero offset. To cancel the zero offset, the present invention alternates the flow to the two cells so that each cell experiences the same sequence of events alternately.
    Type: Grant
    Filed: September 9, 1985
    Date of Patent: September 30, 1986
    Assignee: Shell Oil Company
    Inventors: Thomas L. Stewart, Florian C. Demny
  • Patent number: 4554077
    Abstract: A method of tracing sewage effluent is described in which samples of fluid flows are subjected to high performance liquid chromatography with respective elution systems capable of eluting different selected compounds therefrom, and the concentration of each compound in the sample is determined spectroscopically. The method is used to determine sewage flow paths in natural water bodies, such as rivers, to check for contamination by sewage, to determine possible sewage sources, the detection of uric acid, for example, being indicative of a human source; and to monitor the effluent from sewage treatment plants.
    Type: Grant
    Filed: August 31, 1983
    Date of Patent: November 19, 1985
    Assignee: Devon County Council
    Inventors: Leslie Brown, James Braven, Michael M. Rhead
  • Patent number: 4543191
    Abstract: Capacitance cells comprising concentric tubes are maintained clean of sediment in the space between the inner and outer tubes where capacitance is measured by (1) suspending fibrous strands in the fluid flow outside the inner tube and/or (2) partially plugging the inner tube to increase flow outside the inner tube.
    Type: Grant
    Filed: August 10, 1981
    Date of Patent: September 24, 1985
    Assignee: Shell Oil Company
    Inventors: Thomas L. Stewart, Florian C. Demny
  • Patent number: 4510060
    Abstract: Temperature variations of fluid streams within a BS&W recorder system are controlled by heat exchange and recycling through the pump to reduce waxing and capacitance measurement errors.
    Type: Grant
    Filed: August 10, 1981
    Date of Patent: April 9, 1985
    Assignee: Shell Oil Company
    Inventors: Thomas L. Stewart, Florian C. Demny
  • Patent number: 4492639
    Abstract: A process is provided for measuring the water and sediment content of a wet stream which is predominantly non-aqueous. The process requires removing a sample of the wet stream, extracting a dry stream sample from the wet stream sample, and comparing the dielectric constants of the wet and dry streams. Leakage of any of the wet stream sample into the dry stream sample will adversely affect the comparison of dielectric constants. Accordingly, periodically the apparatus used for the process is checked for leakage by blocking conduits carrying the dry stream sample to a holding chamber.
    Type: Grant
    Filed: February 22, 1984
    Date of Patent: January 8, 1985
    Assignee: Shell Oil Company
    Inventors: Thomas L. Stewart, Florian C. Demny
  • Patent number: 4488970
    Abstract: An improved negative pressure type diesel fuel monitor system that determines a specified level of water trapped in a component of the system and disposed of said water, said water having been separated from the fuel being pumped in the engine fuel line hookup. The system consists of a device to monitor the accumulated water level as it rises in the device, said device also being the facility for separating said water from said fuel and for disposing of said water, said system includes an electrical wiring circuit, connected to the engine run circuit, to operate said device and including a motorized valve to eject collected water therein, a set of logic circuits as part of said electrical wiring circuit, and a combined visual and audio monitor console to record current status of operation of said system.
    Type: Grant
    Filed: October 14, 1981
    Date of Patent: December 18, 1984
    Inventor: Joseph H. Clark
  • Patent number: 4468331
    Abstract: A microprocessor-based analytical liquid chromatograph is programmed to run automatically a series of experiments on a sample mixture using four solvents to determine the solvent strengths and composition needed to optimize resolution.
    Type: Grant
    Filed: September 13, 1982
    Date of Patent: August 28, 1984
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Paul E. Antle, John A. Schmit, Edward L. Smith
  • Patent number: 4439325
    Abstract: A method and apparatus for controlling the operation of a primary filter press to insure the attainment of a desired quality cake in the press including a conduit for feeding a slurry or composition to the filter press, transducers responsive to the volume of slurry delivered to the filter press, the rate of flow, the pressure at the inlet to the press and the characteristics of the slurry solids for producing electric signals proportional thereto, relating at least certain of the signals to compute a quantity K indicative of the quality of the cake being formed in the press when the pressure to the filter press attains 90% of the terminal pressure and modifying the characteristics of the slurry to achieve the desired volume of K. The invention further comprehends the use of a pilot filter press of significantly smaller size than the primary press and fed by the same slurry and operated in the same manner.
    Type: Grant
    Filed: July 11, 1983
    Date of Patent: March 27, 1984
    Assignee: CPC Engineering Corporation
    Inventor: Norman J. Blais
  • Patent number: 4426293
    Abstract: A method and apparatus for removing oil from water. The invention includes a separation vessel for separating the oil by gravity from the water. The generally oil-free water from the separation vessel is pumped under pressure through an ultrafine molecular filter. The concentrate liquid from the ultrafine molecular filter is directed into a concentrator vessel which separates out the oil which remains in the concentrate liquid. The separated oil is directed back into the separation vessel and the remaining liquid is directed back through the ultrafine molecular filter. Ejection water is periodically directed into the separation vessel to discharge oil accumulated in the separation vessel.
    Type: Grant
    Filed: May 4, 1983
    Date of Patent: January 17, 1984
    Assignee: Smith & Loveless, Inc.
    Inventors: Donald G. Mason, Frank G. Weis
  • Patent number: 4425231
    Abstract: A waste water treating apparatus includes a circulation type aeration tank having a downward flow chamber and an upward flow chamber extending in the depth direction and communicating with each other at the upper and lower ends thereof. An oxygen containing gas is supplied to the downward flow chamber and waste water and return sludge are supplied to a given position or elevation of the upward flow chamber to be mixed with a mixed liquor flowing through the upward flow chamber, whereby a reduction zone with a low concentration of dissolved oxygen is formed at the upper portion of the upward flow chamber. Denitrification takes place in the above described reduction zone.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: January 10, 1984
    Assignee: Kubota, Ltd.
    Inventors: Tadao Fujimoto, Tadaaki Kawasugi
  • Patent number: 4416786
    Abstract: There is provided a continuous process for the lowering of the content of toxic materials in waste waters which also contain other oxidizable materials by quickly and continuously ascertaining the requirement of hydrogen peroxide, namely by potentiometric determination of the oxidizing agent requirement in a branched-off side-stream using a strong oxidizing agent, such as peroxymonosulfate, peroxydisulfate, permanganate, hypochlorite or ozone, which acts more quickly than hydrogen peroxide under comparable conditions.
    Type: Grant
    Filed: June 28, 1982
    Date of Patent: November 22, 1983
    Assignee: Degussa
    Inventors: Helmut Knorre, Joachim Fischer, Klaus Stutzel
  • Patent number: 4405462
    Abstract: A system and process has been devised for measuring and constantly maintaining a desired concentration of soluble sulfides in a processing solution for the purpose of fully maintaining its function. Sulfide regenerating solution is automatically introduced into the processing solution in an amount as constantly determined by concentration variations in the processing solution, to thus provide the processing solution with its most effective sulfide content. A constant take-off flow of processing solution is thoroughly mixed with a sulfide stabilizing solution flow to provide a tempered solution flow that is passed through a flow block having a sulfide measuring electrode and a reference electrode. Variable negative voltage generated on the sulfide electrode is sensed and compared with a substantially constant voltage generated on the reference electrode and is amplified in a controller assembly.
    Type: Grant
    Filed: August 9, 1982
    Date of Patent: September 20, 1983
    Assignee: Lancy International, Inc.
    Inventor: David R. Kamperman
  • Patent number: 4402912
    Abstract: A system for the addition of a corrosion inhibitor to an engine cooling system wherein a container in the coolant system holds the corrosion inhibitor in a solid package which is withheld from contact with the coolant solution by a spring under load. The inhibitor package is counterbalanced by a pair of opposed springs with one spring being subject to corrosion when the corrosive effect of the coolant increases; corrosion of the spring allowing the inhibitor package to be urged into contact with the solution to provide treatment thereof.
    Type: Grant
    Filed: December 23, 1981
    Date of Patent: September 6, 1983
    Assignee: Borg-Warner Corporation
    Inventors: Robert H. Krueger, John L. Zambrow
  • Patent number: 4401575
    Abstract: An improvement is provided in a process for measuring BS&W in crude oil by centrifugal separation of dry oil from wet oil and comparison of the dielectric constants of the two, the improvement being the use of at least two seals separating a dry oil chamber from a wet oil chamber and means for flushing the space between the seals with dry oil.
    Type: Grant
    Filed: August 10, 1981
    Date of Patent: August 30, 1983
    Assignee: Shell Oil Company
    Inventors: Thomas L. Stewart, Florian C. Demny
  • Patent number: 4400270
    Abstract: An ultraviolet sterilization and disinfection system for fluids which includes apparatus for sensing selected operating characteristics such as physical characteristics of the fluid to be disinfected or sterilized and the operating conditions of the ultraviolet sources proportioning these variable and generally non-linear parameters and modifying such factors as fluid flow, ultraviolet energy imparted to the fluid to insure destruction of selected organisms without the use of excessive energy. Control may also be provided for the admission of selected quantities of disinfecting chemicals such as chlorine to the fluid.
    Type: Grant
    Filed: November 9, 1981
    Date of Patent: August 23, 1983
    Assignee: ADCO Aerospace, Inc.
    Inventor: Leon Hillman
  • Patent number: 4385973
    Abstract: In a process for disinfecting water by anodic oxidation in a reactor the volumetric flow rate, current density and contact time are selected so that there is an excess of reaction products having oxidizing power in the water at the exit from the reactor, which gives rise to continued disinfection downstream of the reactor. The process is particularly applicable to water for swimming pools.
    Type: Grant
    Filed: February 1, 1980
    Date of Patent: May 31, 1983
    Assignee: August K. Reis
    Inventors: August K. Reis, Norbert L. Kirmaier, Meinolf H. A. Schoberl
  • Patent number: 4383046
    Abstract: In mixed bed ion exchange resin regeneration processes, transfer of resin after classification is controlled by detecting a change in a parameter of transfer water dependent on ion concentration, e.g. conductivity. The process includes increasing the ion concentration of the transfer water. The increased ion concentration ensures that large percentage uncontrolled fluctuations in the conductivity of the water do not mask the change required to be detected. The ion concentration can be increased by adding, for example, decationized water to the transfer water.
    Type: Grant
    Filed: February 22, 1982
    Date of Patent: May 10, 1983
    Assignee: Northern Engineering Industries Ltd.
    Inventor: James R. Emmett
  • Patent number: 4381240
    Abstract: A swimming pool water conditioning system which incorporates a pump-fed, pool water filtration system; a hydrochloric acid-consuming electrolytic chlorine gas generator; and a manifold system to draw the chlorine gas into the flow through the filtration system, to serve in combination as a device to both safely chlorinate and pH-adjust the water in the swimming pool in a controlled manner, so that bacteria growth and the acid level in the pool can be controlled with a minimum of effort and expense.
    Type: Grant
    Filed: May 5, 1981
    Date of Patent: April 26, 1983
    Assignee: Harry M. Weiss
    Inventor: Thomas V. Russell
  • Patent number: 4370233
    Abstract: A method is disclosed for the chemical detoxification of anaerobically digested organic sludge containing toxic heavy metals in insoluble form. A quantity of the sludge is transferred from a conventional anaerobic digester to an insulated reactor vessel where the sludge is mixed and aerated at a rate sufficient to raise the oxidation reduction potential of the sludge to above +300 mv. and to maintain this condition for a period of 6-12 hours during which the heavy metals are converted to their desired oxidation state. The sludge is then acidified under controlled conditions to pH 1.0-3.0 for a period of 6-12 hours to solubilize the heavy metals. Conventional dewatering techniques are used to separate the detoxified, acidic sludge and the acidic, heavy-metal-containing water. The sludge may be neutralized for safe land application, and the metals can be recovered from the water using existing conventional techniques.
    Type: Grant
    Filed: July 10, 1981
    Date of Patent: January 25, 1983
    Assignee: Cornell Research Foundation, Inc.
    Inventors: Thomas D. Hayes, Randolph M. Kabrick, William J. Jewell
  • Patent number: 4366064
    Abstract: Wastewater, particularly blowdown from a recycle gas-scrubbing and gas-cooling system of a blast furnace, is treated in a two-stage chlorination unit, the first stage including a chlorine addition at a pH of about 8.5 to about 10, preferably 9-9.5, and the second stage continuing the chlorination reaction at a pH of about 6 to about 8, preferably 7-7.5, while monitoring the oxidation-reduction potential of the second stage to utilize as a control point for chlorine addition in the first stage. Various contaminants, notably the nitrogen-containing compounds, are destroyed in the chlorination steps. A caustic or lime pretreatment is preferred for scale control at a pH of about 10.5 to about 11, preferably 10.7, while lime pretreatment is performed at a pH of about 9.6 to about 10, preferably 9.8. After chlorination, the process stream is preferably passed through activated carbon to remove organics.
    Type: Grant
    Filed: November 5, 1981
    Date of Patent: December 28, 1982
    Assignee: United States Steel Corporation
    Inventors: Edward L. Mihelic, Samuel B. Schlosberg
  • Patent number: 4268397
    Abstract: A waste water-treating method, which comprises the steps of: adjusting the pH value of an aqueous solution containing a nitrous acid radical within a range of 2 to 5; treating said aqueous solution with hydrogen peroxide to oxidize the nitrous acid radical into a nitric acid radical; and throwing away the waste water in the neutralized form.
    Type: Grant
    Filed: July 27, 1979
    Date of Patent: May 19, 1981
    Assignee: The Furukawa Electric Co., Ltd.
    Inventors: Toshio Horie, Shouji Tomioka, Nobuyoshi Mine
  • Patent number: 4229298
    Abstract: A method for determining the thickness of a charge wall being formed against the side wall of a rotating centrifugal basket by flow of charge material into the basket comprises the steps of establishing a capacitance across the charge space of the basket and sensing any change of capacitance which results as the charge wall thickness is increased by the flow. An apparatus for determining the thickness of the charge wall formed against the side wall of the centrifugal basket includes an electrically conductive plate disposed in the basket inwardly of the charge space and a source of voltage for establishing an electric field between the plate and the side wall. A capacitance sensor senses any change in the established capacitance resulting from the formation of a charge wall in the basket.
    Type: Grant
    Filed: February 5, 1979
    Date of Patent: October 21, 1980
    Assignee: The Western States Machine Company
    Inventor: Joseph B. Bange