Abstract: Optimum concentration of the acid-scrubbing solution employed in a scrubbing tower for removal of malodorous and/or toxic gases from the air is maintained automatically in a control system which senses the electrical conductivity of the solution to control acid-feeding apparatus. High and low concentration alarms are also provided to warn of malfunction.

Abstract: This invention relates to a process for the controlled flocculating or precipitating of foreign substances from a liquid by the addition of a flocculating agent, at least a partial quantity of the liquid being treated with a dosed amount of the flocculating agent, the flocculation or precipitation caused thereby in said partial quantity being measured by a turbidity measurement and the addition of the flocculating agent to the liquid to be treated being determined on basis of the turbidity measurement. An apparatus for the carrying out of such a process also constitutes the object of this invention.

Abstract: An electromechanical monitor for rapid quantitative detection of an anesthetic gas in the gaseous flow of an anesthesia administration system wherein deformation due to directly proportional reversible swelling of an elastic membrane in contact with the gas is mechanically detected and translated into an electrical signal. The membrane is preferably disc-shaped, constructed of silicone rubber, and horizontally mounted within the device. The electrical signal developed may be employed to generate an information display and/or provide automatic control of anesthetic and other gas content within the system.

Abstract: In a milk processing system wherein heat treated milk is initially separated into high-fat and low-fat milk and subsequently reconstituted by adding a selected proportion of high-fat milk to the low-fat milk, control means are provided for automatically controlling the proportion of high-fat milk mixed with the low-fat milk to provide a milk blend of standardized butterfat content which is then homogenized. The control means includes a photoelectric monitoring system for continuously measuring the butterfat content of a sample of the homogenized milk as the latter flows continuously through the processing system under pressure of the homogenizer in the system. The butterfat content measurement is converted to digital signals which are compared to a pre-set digital signal corresponding to a desired butterfat content level to produce a digital corrective signal which controls a digital valve regulating the proportion of high-fat milk blended with the low-fat milk in the processing system.

Abstract: Apparatus and a method for preparing a particle suspension by measuring and adjusting the concentration of a suspension while the suspension is being subjected to particle-dispersing physical agitation are disclosed. The invention has particular application to the preparation of a cytologic specimen exhibiting isolated single cells, which specimen can be subjected to machine analysis in a flowthrough type counter or be applied to slides with even dispersion and uniform density in monocellular layers suitable for microscopic analysis.

Abstract: A mobile agricultural sprayer having a control system for controlling the amount of chemical additive added to a water stream from a mobile storage tank in response to a chemical additive concentration detector is disclosed. The mobile sprayer utilizes a mobile water storage tank and at least one chemical additive tank which communicates with the water to be sprayed at a point between the tank and the sprinkler heads. A pump draws water from the storage tank and directs it under pressure to the sprinkler heads. The chemical additive is typically added in liquid form, such as a solution or a slurry, at a point preferably upstream of the pump inlet while concentration is measured at a point between the point of addition of the chemicals and the sprinkler heads and preferably before the inlet of the pump. The concentration detector transmits information to a monitor which controls the amount of chemical introduced into the water to be sprayed.

Abstract: A system for controlling the concentration of developer solution, which includes a toner concentrate and a carrier, to be substantially equal to a predetermined concentration. The system, which is used in conjunction with a photocopying apparatus, comprises a source of light directed through the solution and a photosensor, on which the light source is focused, that generates an output signal proportional to the amount of light reaching it. A reference signal generator produces a reference signal substantially equal to the photosensor output signal that corresponds to the predetermined solution concentration. A comparator receives both the photosensor output and the reference signals and produces an error signal proportional to the difference between the two. The error signal is used to modulate the amount of time during which a servo mechanism is operated to add toner concentrate to the solution and thereby control solution concentration.

Abstract: A first inductive coil in the form of a bifilar winding is wound on a ferrite ring core with the two sections of the bifilar winding connected in series, the junction of the two sections forming the center tap of the coil. A capacitor is connected across the first coil to form a parallel resonant circuit therewith. The two ends of the first coil are respectively connected to a predetermined capacitance and to an electrode adapted to form a capacitative element whose dielectric includes a fluid under test. The center tap of the first coil is connected to the output of an amplifier whose input is connected to a second, detector coil comprising a separate winding on the ferrite ring core located substantially at the mid-point between the ends of the bifilar winding. The second coil is arranged to be inductively coupled to said first coil such that the mutual inductance between the first coil and the detector coil completes a feedback loop for the amplifier.

Abstract: The invention concerns a novel apparatus for automatically preparing a solution of controlled salt concentration, which comprises a mixer container in which preparation of the solution may take place, a regulator device for regulating supply of components of the solution to the mixer container, a level detector for detecting the level of solution in the mixer container in the vicinity of a prescribed primary level, a concentration probe for detecting concentration of salts in the solution, and a control device connected to receive electronic signals transmitted from said level detector and said concentration probe for producing a control output signal to control said regulator device, whereby the level of solution in the container is maintained in the vicinity of said prescribed primary level and the concentration of salts in the solution is maintained in the region of a predetermined value.

Abstract: An end point quality control light circuit for a water demineralizer. The quality control light circuit comprises a power cord, a housing for the electronics, and a probe-light assembly. The probe-light assembly includes a pair of spaced apart A.C. energized probes, and applies approximately 12 volts to the water. The probes are transformer isolated from the power input, and the final drive to an indicating lamp is transistorized. The current through the probes, directly proportional to the quality of the water, develops a voltage that is compared to a threshold voltage. The indicating lamp is illuminated to indicate high water quality, and is switched off by the final drive transistor when the water quality becomes unacceptable. An optional switching circuit, isolated from the quality control circuit, enables the actuation or control of external devices in dependence upon water quality. Various techniques for minimizing leakage currents are also disclosed.

Abstract: A process control circuit which is adapted for the control and monitoring of a plurality of parameters in one or more metal-depositing baths, has parameter control circuit blocks for each of the parameters to be measured. Each of the parameter control circuit blocks has a measuring stage for producing a measured value corresponding to one of the parameters, a calibration stage for calibrating the measuring stage, a comparison stage for comparing the measured value to a stored nominal value, and a dosing circuit which is connected to the comparator and which doses the metal-depositing bath in response to a comparison signal from the comparator.

Abstract: The invention relates to apparatus for regulating the pH value, or other similar values, of a solution. The apparatus includes an actual value transmitter, a desired value transmitter, a regulator controlled by the two transmitters, and a servo unit controlled by the regulator for adding a measured amount of additive to the solution. The servo unit includes a pulse driven metering pump to provide the supply of additive. The applied pulse frequency has a logarithmic relationship to the control signal derived from an error signal which makes possible exact regulation corresponding to the logarithmetic relationship between the pH value and the concentration of additive introduced into the solution.

Abstract: The composition of etchant solution withdrawn from an etcher is monitored to diagnose a component deficiency. A light sensor is responsive to the color density of light rays passing through the etchant. A meter relay is responsive to the light sensor and if the color density of the etchant falls outside preset levels a pump is energized causing addition of a constituent component into the etchant. A second light sensor senses the color density of the light rays passing through the etchant after the addition of the constituent component. A second meter relay is responsive to the second light sensor. If no improvement of the etchant color is detected, the second meter relay causes the discontinuance of the constituent component addition and switches to the addition of another constituent component.

Abstract: An automatic replenishing system for maintaining the chemical concentration of the liquid in a film processing tank, which automatically energizes a replenishing pump at regular timed intervals (e.g. every 30 seconds) regardless of whether or not the control circuitry indicates a need for replenishment, and which includes an element for sensing the density and velocity of the film and for producing a combined signal which controls the running time of the pump after each energization. The replenishing system also includes a second replenishing pump for maintaining the condition of the liquid in the processing tank, which second pump is energized automatically after a predetermined number of said regular timed intervals, or after a predetermined number of said regular timed intervals in which a zero film density or non-use condition has been detected for a preset running time.

Abstract: A method and apparatus for measuring and keeping constant the water content in a highly heated salt bath, by measuring the change in dew point of a gas flowed over the salt bath.

Abstract: An integrated monitor and control system for continuously monitoring and controlling pH and free halogen concentration in swimming pool water is provided, comprising, in combination, a first electrochemical flow cell having two electrodes and through which swimming pool water flows, giving rise to an electric potential between the electrodes in proportion to hydrogen/hydroxyl ion concentration in the pool water; means for measuring the electric potential across the electrodes in a manner correlated with pH of the pool water; a second electrochemical flow cell having two electrodes and through which swimming pool water flows giving rise to an electric potential between the two electrodes in proportion to the oxidation/reduction potential of the pool water; means for measuring the electric potential across the electrodes in a manner correlated with halogen concentration in the pool water; a first operational amplifier in electric connection with the first cell and arranged to respond to a pH outside a predeterm

Abstract: A system for controlling the silver ion concentration of a silver halide emulsion made by mixing alkali halide and silver nitrate solutions which are delivered continuously to a vessel at primary addition rates. The silver ion concentration in the vessel is measured to establish the deviation from a desired concentration. Where the error is within a limited or normal range, a low signal selector circuit causes a pump in a secondary flow loop to deliver a secondary amount of whichever solution is needed to offset the deviation. Where the error is abnormal, a high signal selector circuit alters the primary addition rate of the alkali halide solution to offset the deviation.

Abstract: Long chain polymer flow promoting additives including guar gum, polyethylene oxide and polyacrylamide used to maintain Newtonian flow characteristics in an extended velocity range are mixed into a neutral density liquid having a significant variation of electrical conductivity with the dilution of the neutral density liquid, to provide a stable additive mixture. The concentration of the neutral density carrier liquid when diluted as a working liquid in use within a machine or system may be readily determined by measuring the electrical conductivity of the working liquid, thus permitting the working liquid content of flow promoting additive to be readily determined and controlled.

Abstract: A reserve supply of diazotype developing liquid from which liquid is supplied to semi-dry diazotype developing apparatus is maintained at both a substantially constant level and the required concentration of azo coupling component by introducing solvent for the liquid to restore the liquid level upon a decrease of the supply volume, sensing the specific gravity of the supply liquid by a hydrometer, and counteracting the decrease of concentration resulting from solvent addition by introducing a liquid concentrate containing the azo coupling component and electrolyte in response to a lowering of the hydrometer.

Abstract: A method and a processor having infrared sensed chemical replenishing system for processing photosensitive material. The processor includes a replenishing circuitry having a power supply; a pulsed infrared sensor electrically connected to the power supply for measuring the width of photosensitive materials; a pulse generator circuit for generating a pulse width and repetition rate to the infrared sensor means; and a summing circuit for producing a summation of all latched input elements transmitted from the sensor. The replenishing circuit also includes a replenishment calibration timing circuit for producing a replenishment command signal following a successive time interval equal to the time required for the processor drive to turn one revolution, and a control circuitry for controlling the chemical flow of the replenishment system.

Abstract: Control apparatus for swimming pools to automatically regulate chlorinator and acidifier operation, thereby maintaining a desired chlorine residual and pH level. A first liquid sample from a swimming pool along with a chlorine reagent substance and a second liquid sample from the pool along with a pH reagent are sequentially introduced into a sample cell with a light source projecting light through the sample cell onto first and second photoelectric cells. The first photocell produces a signal having a magnitude that is directly proportional to the chlorine residual in the first liquid sample, and the second photocell produces a signal functionally related to the pH level of the second liquid sample.

Abstract: Apparatus is disclosed for automatically mixing and circulating cleaning solutions through dairy equipment, such as in-place milk line equipment, bulk storage tanks, or the like. The apparatus comprises individual pumps for supplying ingredients, such as a detergent, an acid and a sanitizer, in a predetermined sequence to a mixing receptacle for mixing with a solvent such as water to form different types of cleaning solutions which are then circulated by a main pump through the equipment in a predetermined sequence. Control means, including a timer, are provided to fill the mixing receptacle with water and to operate the individual pumps and the main pump in a predetermined sequence to provide desired cycles of operation, such as first rinse (with water), wash (with detergent), second rinse (with acid), OFF, sanitize (with sanitizer), and OFF.

Abstract: Disclosed is a wet processing station in which control of the PH of the processor liquid is mandatory within predetermined limits, the processor including a tank having means to subject product to a bath of processing liquid. A PH monitoring probe is positioned in the tank with a pump in the tank for mixing processing liquid therein. The pump has a liquid intake and a discharge, the intake being positioned closely adjacent to the probe so that liquid being mixed in the tank will flow across the probe into the intake of the pump. A processing liquid concentrate holder is coupled to liquid concentrate carrying means which connect the holder to the probe, the liquid carrying means having an outlet which is positioned to discharge concentrated processing liquid directly onto the probe. Probe monitoring means which is responsive to the output of the PH monitoring probe provides a signal output when the PH of the processing liquid reaches at least a predetermined lower limit.

Abstract: Apparatus and method for analyzing liquid sample comprising flowing a stream including a liquid continuously in a conduit, detecting a flow rate characteristic in the conduit and generating a signal in response thereto, and increasing, decreasing or maintaining, unchanged the flow rate of the stream in the conduit in response to the signal, the flow being increased or decreased by the flow into the conduit of another fluid without changing the concentration of the aforementioned liquid. The continuing flow of the liquid may be the flow of a segmented sample-reagent liquid, and the other fluid which is added may be a gas.

Abstract: An automatic leaching system for the hydrometallurgical production of zinc comprising a pH meter and means for detecting the feed rate of calcine. The pH meter is provided with means for automatically washing the electrodes thereof so as to be capable of continuously and automatically detecting the pH value of the slurry obtained by mixing a spent electrolyte with the calcine. The system comprises a feedback control circuit and a feed-forward control circuit in which the flow rate of the spent electrolyte supplied to the system is the manipulated variable, and the pH value of the slurry is the controlled variable. These control circuits are used for the pH control so that the pH value of the slurry can be maintained constant by controlling the flow rate of the spent electrolyte.

Abstract: The chemical activity of the developer in a film processor is stabilized by a replenishment system which includes a controlled fluid supply arrangement operative to effect an initial replenishment based upon certain predetermined factors including the length or area of a sheet to be processed as detected at the processor input, an assumed minimum exposure present on each image-bearing sheet to be processed, and the customary degradation of developer activity resulting from oxidation effects as determined empirically. The initial replenishment is later supplemented, if necessary, by effecting additional replenishment following the processing of film sheets, based upon a determination of the actual image density and image area present in those sheets.

Abstract: The invention concerns a novel automatic metering system for producing a liquor containing a predetermined concentration of at least one component thereof, which comprises a mixing tank in which the liquor components are mixed, a metering device adapted to meter out at least one of the components into the mixing tank, an analyzer adapted to measure the concentration of the component(s) required at a predetermined concentration and a data processing unit, with an input from the analyzer and an output to the metering device, being programmed to effect an operational cycle which comprises computing the deviation of the measured concentration from the predetermined concentration of the component(s), correlating the deviation with the amount of at least one of the components necessary to be metered out, substantially to reduce said deviation by a reduction factor of less than 100 percent, and automatically operating the metering device to meter out the correlated amount, and to repeat said operational cycle until

Abstract: Internal water balance within a liquid carbamate recycle urea process is controlled. Pressure in decomposer and/or condenser system can be varied to effect control. Also, refractive index of carbamate recycle solution can be determined and related to water balance.

Abstract: This invention relates to a system for automatically measuring and controlling the sulfate content of a chromium plating solution including sulfuric acid and chromium trioxide in water, the measuring system including means for automatically applying a constantly increasing voltage across the electrodes of a probe immersed in the solution, and for detecting the peak current flow through the solution between the electrodes, which peak amplitude is directly proportional to the percent sulfate in the solution. The electrodes are especially designed to produce accurate readings and are of materials that are noncorrosive in the plating solution. The system further includes a recording device for recording the percent sulfate in solution in response to the peak current amplitude detected.

Abstract: The disclosure is directed to automatic flow blending of gas mixtures useful for calibrating gas analyzing instruments of the kind used in measuring atmospheric pollutants and the like. According to the disclosure the component gases reduced in pressure from the storage pressure, are continually mixed in a mixing zone at low pressure and pumped to high pressure for charging high pressure storage vessels. The mixture in the high pressure charging line is continuously monitored with a gas analyzer instrument. Variations from the desired blend are converted into an analog signal which is used to control various valve mechanisms for regulating the flow of gases to the low pressure mixing zone so that a match of the desired blend of gases is obtained.

Abstract: In an arrangement for regulating the moistening solution mixture for use in an offset printing press, a tank is provided with two separate spaces, one for the moistening solution mixture and the other for a moistening solution additive. A conduit system containing various regulating devices is connected to the tank for regulating the introduction of the additives into the mixture and for the supply of the solution to the printing unit, a crystal sand filter is located in the conduit system for filtering the mixture and a pump, associated with the filter, directs a part of the filter mixture to the printing unit and returns a part of the mixture to the tank. A flow measuring electrode is arranged in the conduit system and is operatively connected to the regulating devices for controlling operation of the arrangement.

Abstract: A simple apparatus and process for monitoring a selected component of a fluid system are provided wherein the apparatus comprises a simple diffusion probe, an electronic pumping means and a reading means whereby the diffusion and pumping rate are read directly as electrical current.