Abstract: A fail safe circuit is provided in a salinity monitor having a salinity indicating panel for visually presenting salinity levels and a salinity cell for sensing salinity levels. The salinity cell is electrically connected to the salinity indicating panel by a plurality of salinity cell leads which supply electrical signals to the salinity indicating panel for indication of salinity levels. The fail safe circuit enables an alarm when a salinity cell lead becomes disconnected from the salinity indicating panel. Also, a back-up circuit is provided for enabling an alarm should the fail safe circuit become inoperative.

Abstract: A salinity indicatory system useful to monitor variations in the salt content of water sources provides for the simultaneous monitoring of a plurality of test stations and the operation of automatic alarm and dumping means when salinity concentrations reach or exceed predetermined set points. The alarm and dump set points are capable of being set at different levels to provide for an indication of an approaching dump condition. The system includes temperature compensating networks having thermistors and associated resistor networks mounted inside the salinity cell to function both as temperature shaping resistors and electronic scaling resistors, thereby providing the system with multi-range capability. A summary fault alarm circuit allows all alarm conditions occurring with respect to any of a plurality of perimeters to be signaled through a single, summary fault relay.

Abstract: The speed of a vehicle, and particularly a ship, is controlled to minimize the sum of fixed and variable operating costs. The variable costs are incurred substantially only due to fuel usage. The rotational speed and torque parameters of the ship propeller shaft are measured and utilized to derive an expression for shaft horsepower in terms of these parameters. The variable cost function is derived from the horsepower function, fuel factor, unit volume fuel cost and voyage distance for various ship speeds. The fixed cost function is determined on the basis of voyage time for the various speeds, loading time and total annual costs for maintaining the ship per unit of time. The ship throttle is controlled to operate at the speed at which the total fixed and variable costs is minimized.

Abstract: A cell body having a pair of electrodes insulated from each other and adapted for direct immersion and use in commercial, laboratory, or industrial fluids or process streams, the cell being usable at temperatures below freezing and above the boiling point of water. The cell includes an insulated ultra pure antimony electrode and an insulated electrode of noble metal, the noble metal of the one electrode being immersed in the process stream as is the pure antimony electrode. The cell provides a self-contained solid state unit with the two electrodes adapted to measure pH in fluids or process streams containing solid mineral or ore particles, in acid, neutral or basic solutions of a wide range of temperatures and pressures, including vacuum applications and this system requires no external or internal reference or standard electrodes.

Abstract: A simplified clean conductivity or pH cell assembly comprising a solid plastic cell body and a test fluid conduit comprising a clean pipe fitting, affixed to the forward face of the solid body by means of an external clamp and a seal such as an O-ring. The clean pipe fitting is preferably formed of stainless steel and the internal surface thereof which comes in contact with the test fluid is plane and has no crevices or the like which could cause contamination of the fluid.Pencil shaped electrodes are fixed in said solid body and extend therefrom into the test fluid in the conduit to be measured. The face of the solid body which is in contact with the test fluid is plane with no cavities, crevices, holes, projections, restricted channels, or the like. The electrodes for conductivity or pH measurement are cleanly formed of glass or stainless steel or other suitable material and have no surfaces which might result in contamination or the collection therein of dirt and the like.

Abstract: A simplified system for practical use in the measurement of specific ion concentrations. A probe for introduction into a fluid stream to measure the ion concentration thereof and said probe comprising an ion sensitive electrode for immersion in a fluid stream in combination with an annular elongated electrode having a noble metal, such as one of the platinum group of metals, on an end surface thereof for immersion in the fluid stream. The combination of the ion sensitive electrode, and the annular elongated electrode having an end thereof with the noble metal is placed in the fluid stream to be measured and is electrically connected to a measurement and/or indicating instruments.

Abstract: A system for coupling electrical power to a rotary shaft without mechanically contacting the shaft includes a stationary transformer primary core positioned adjacent but spaced from the shaft so that the shaft forms part of a complete magnetic flex path for the core, and an insulated conductor mounted directly upon the shaft in the form of a winding which is positioned to be inductively associated with the transformer primary.

Abstract: A circuit for measuring the PH of fluids includes a coaxial symmetrical probe having a PH probe surrounded by a reference probe; the conductor on which the PH signal passes from the probe to the control panel is within a shield to which is applied the PH voltage; and the differential amplifiers which receive and process the PH and reference signals are mounted on a conductive surface to which is applied the PH voltage.

Abstract: A circuit for monitoring the conductivity of a solution has a conductivity cell with a grounded cell electrode that is operated at a distance from the reading station. A shielded cable houses the signal carrying conductors and the free end of the cable shield is purposely not grounded.

Abstract: A circuit for indicating the ratio of an unknown part value to a known part value, or the percentage error between an unknown part value and a known part value, or the direct value of an electrical part to be measured, has a first operational amplifier for developing a voltage proportional to the ratio of an unknown part value to a known part value and a second operational amplifier for subtracting a predetermined amount from said ratio voltage so that the resultant output from said second amplifier provides the desired percentage error of the unknown part value to that of known part value.

Abstract: A conductivity cell for measuring the conductivity of a liquid comprising a pair of spaced apart electrodes insulated from each other. The proper spacing of the electrodes is provided by a washer formed of insulating material and it is strong, rigid and highly stable chemically and mechanically and is substantially unaffected by wide temperature variations. A single electric conducting element extends through the cell and at one end is electrically fixed to one of the electrodes. The single electric conducting element is adjustable to maintain the two electrodes and insulating washer in proper position. A protective and insulating shield is provided for detachable connection to the conductivity cell to protect the electrodes.

Abstract: A circuit for monitoring the conductivity of a solution has a four probe conductivity cell which is supplied by a constant current source to provide a signal proportional to the conductivity. A thermistor is connected in the feedback circuit of an operational amplifier and responds to temperature changes in the solution to change the gain of the amplifier and maintain the circuit output at a predetermined level.

Abstract: A system for determining the resistance of an electrolyte into which a conductivity probe is immersed, the system including a thermistor network, a probe or conductivity cell, and amplifiers all of which are so combined that the changes in electrolyte concentrations causing variations in resistance are measured with corrections being made for electrolyte temperature variation. The probe and thermistor networks control the feedback of the amplifier, and the probe and thermistor networks being arranged to adjust the output whereby the signal is in true proportion to conductivity.