Abstract: There is provided a method for adapting a commercially available relational database management system for a microcomputer so that it has the ability to access foreign data such as real time data for the examination and processing of that data by the DBMS. In this connection the operating system being used in the computer is provided with a kernel which has a driver which simulates for the DBMS a standard file format for the foreign data that is to be obtained. The information itself is obtained by a server activated by the driver. The server gets the foreign information and passes it back for the simulated file so that the simulated file can be addressed by the normal DBMS queries or commands.

Abstract: An improved expendable oxygen sensor particularly useful for measuring the dissolved oxygen content of an aluminum killed, high silicon steel bath is disclosed. The device has the typical closed end tube of solid electrolyte containing oxygen reference material, but differs from previous sensors in that a shield is provided which protects the solid electrolyte from being in contact with the bath until the solid electrolyte has had a chance to heat up more closely to the temperature of the steel. This shield, in one form, consists of a closed end tube positioned to surround the solid electrolyte and spaced from the solid electrolyte in order to prevent erroneous outputs from the sensor due to oxidation of the shield material.

Abstract: This invention provides a method for producing header mounted sensors, such as a chemically sensitive ISFET structures, which comprises steps which include providing a plurality of electrochemically sensitive ISFET sites on a semiconductor substrate with a source region, a drain region and an electrochemically sensitive gate region on the front of said substrate with contacts for said regions on the back of the substrate. A glass carrier, such as borosilicate glass is provided for the substrate. The carrier has a hole in it to maintain uncovered the contact areas of the ISFET sites and the carrier also has leads to provide electrical access to the area of the holes from the edges of the carrier. The substrate is electrostatically bonded to the glass carrier at the periphery of each of the ISFET sites and the boundaries of the individual ISFET sites are V-groove etched to form isolated individual silicon mesas each representing an individual ISFET structure.

Abstract: An improvement is provided for printer such as the dot matrix or thermal type, in which the printhead is stepped across the paper over a multicolor ribbon supplied from a pivotally mounted cartridge and transported through a plane between the line of traverse of the printhead and the surface of the paper. The ribbon is guided by guiding surfaces positioned on each side of the printhead, close to the printhead, and mounted to move with the printhead across the paper so that the guide surfaces will guide the path the ribbon takes to one which passes between the printhead and the paper with the guide being moveable in steps in a direction normal to the traverse of the printhead and parallel to the plane of the ribbon so as to position a selected color band of the ribbon under the printhead to select the color to be printed as the printhead traverses the paper.

Abstract: In analog multiplexers using solid state multiplexing relays and having a shunt capacitor circuit across each input channel as part of a filter for normal mode noise, common mode noise is rejected by opening the shunt capacitor circuit in at least the selected channel and preferably all channels during the switching cycle of each channel for a full cycle of the a.c. line frequency, the opening spanning the deselection time for the selected channel and the selection time for the next channel.

Abstract: A method for operating a dot-matrix printer to allow printing in the accelerating and decelerating regions of the carriage traverse, which comprises the steps of: firing the wires for registration at the present position of the carriage and stepping the carriage by energization of a stepper motor driving the carriage for the period required to complete the step when accelerating the carriage or the period required to brake the carriage when decelerating the carriage. These times will decrease as the carriage accelerates to the desired velocity and will increase as the carriage decelerates from the desired velocity.

Abstract: A multipoint recorder with a slow effective chart speed is operated to provide good visibility for the most recent record. A number of consecutive values for each point are scanned and stored. These values are recorded by a high speed printing mechanism during a first period of the recording cycle after which the chart is advanced forward for the remaining period of the recording cycle to a point which makes that record easily visible. At the end of the recording cycle the chart is retracted to start the next printing period with the printing mechanism at a point which corresponds to that required make the record look like a continuous line and to provide the desired time scale along the chart. To accomplish this the cycle time is coordinated to the chart speed and the number of consecutive scans recorded during each recording cycle.

Abstract: The invention provides an electronic horn for an alarm circuits of the type in which the d.c. power supply for the horn will be of a particular polarity to indicate an alarm condition. The circuit provides a piezo sounder connected across the terminals of the power supply, an inductor connected in parallel with the piezo sounder to form a tank circuit therewith and current modifying means connected in series with the tank circuit to modify the current through the tank circuit in response to the output of an R/S flip-flop which is periodically set by a clock signal at a frequency corresponding to the frequency desired for the fundamental audible tones of the sounder. The duration of the clock output pulse which makes the modifying means conductive must be such that the capacitance of the sounder is charged by the supply before the output of the clock permits a change of state in the flip-flop to make the modifying means nonconductive.

Abstract: A strobe light circuit is provided for flashing a strobe flash unit at a desired frequency. An inductor is repetitively connected and disconnected across a d.c. power line by a switch means so that energy is stored in the inductor during the period when the circuit is complete. The flash unit and a capacitor are connected in parallel so that the capacitor can discharge its stored energy to the flash unit when the voltage across the capacitor exceeds the threshold firing voltage of the flash unit. The parallel combination of the flash unit and the capacitor is in turn connected in series with a diode, and the resulting series circuit is connected across the inductor with the diode being connected in polarity such that current will not flow from the power line through the flash unit or the capacitor.

Abstract: A control for the fuel input to a once-through boiler connected to supply steam through a throttle valve to a turbine-generator so that the rate of energy delivery to the boiler matches the rate of energy demand on the boiler as represented by demand signal. The fuel control involves comparing a demand signal indicative of the desired energy output rate for boiler with a signal indicative of the heat released to the furnace of the boiler and controlling the fuel input rate with a proportional and integral controller so that the fuel feed rate, such as coal feeder speed, is controlled so as to bring the signals into equality. The heat release signal is obtained by first calculating a lagged value of a quantity which corresponds to boiler output, such as steam flow or turbine first stage pressure, divided by fuel feed rate, such as feeder speed. That lagged quantity is then multiplied by a quantity corresponding to the value of the fuel feed rate.

Abstract: Compensation for the temperature sensitivity of the output of a potentiometrically operated ISFET probe whose drain-source voltage and drain-source current are held constant is provided by using a Nernstian temperature correction of the difference between the ISFET output and the isopotential voltage of the probe and offsetting the resulting difference by the isopotential pIon value. An ISFET/NISFET pair provides a cancellation of variations due to manufacturing.

Abstract: There is provided a system for measuring a selected ion in a solution so as to avoid noise pickup from AC parasitic currents and measurement offset from DC parasitic currents, such as are frequently found in pH measurements on low conductivity grounded solutions like high purity water. The system in one form has an operational amplifier with an ion selective electrode connected to its inverting input, a counter electrode connected to its output, and circuit common connected to the non-inverting input, so that the potential of the ion selective electrode is continuously driven to circuit common. The reference electrode of the system is connected to a high impedance measuring circuit for measuring the voltage level of that electrode with reference to circuit common as a measure of the concentration of the selected ion in the solution.

Abstract: A variable capacitor, which may be a humidity sensitive capacitor, and a fixed reference capacitor are connected at a node. The node is clamped at a reference potential during a first phase of a two phase measuring cycle as the variable capacitor is charged to a fixed voltage and the fixed capacitor is charged to a feedback voltage. The node is unclamped during the second phase and the capacitors are connected in a series loop to allow a redistribution of the charge in the capacitors or force a reversal of that charge with a voltage source. The deviation of the node from its reference potential after charge redistribution occurs is used as input to a feedback circuit which integrates that deviation over a number of cycles until it provides a feedback voltage of magnitude sufficient to cause the node deviation to be reduced to zero. A second reference capacitor can be supplied to provide an offset.

Abstract: A circuit for measuring the conductivity of a solution by applying a known ac current source across a pair of electrodes in the solution and utilizing an analog-to-digital dual slope converter, such as those of the integrated circuit type which include capacitor sampling of the signal input, for conversion of the ac voltage drop across the electrodes. The circuit includes means for synchronizing the ac current to the clock to time the sampling so that the same polarity of signal input is always obtained. Where the known ac current source consists of switching the sense of the electrode connections to a combination of a dc source in series with a known resistor, used for supplying the reference input to the converter, a dc signal input, instead of ac, obtained by including the voltage drop of the switch with the drop across the electrodes in the signal sampled. With this arrangement, higher cell constants can be used to minimize the effect of the voltage drop across the switch.

Abstract: The square root insertion circuit of this invention has an operational amplifier circuit with a multiplying circuit of the voltage-time product type in its negative feedback path. The multiplying circuit is connected so that the time factor is proportional to the amplifier output signal and the voltage factor is also proportional to the amplifier output signal. Thus, the multiplying circuit acts as a squaring circuit to cause the output signal of the amplifier to be directly related to the square root of its input signal.

Abstract: There is provided an expendable device for use with a standard immersion sensor for a molten metal bath to simultaneously hold a standard immersion sampler in juxtaposition to the sensor when the sensor is in its protective sleeve at the end of a lance ready for immersion into the bath. This device provides another expendable heat insulating protective sleeve for accepting in its end the sampler with means being provided for maintaining a side by side relationship between the sampler sleeve and the sensor sleeve during immersion. This combination may advantageously have a vent pipe extending between the sleeves to allow air displaced from the sampler by influx of the sample to vent to a region above the molten metal bath by way of a passage in the sensor sleeve.

Abstract: A method and apparatus for carrying out the control of a process using a distributed process controller wherein each controller receives during consecutive time slots of a scan cycle inputs from the process representing measured values of process variables to be controlled by the control loops of the system. Control is provided by the use of a preselected algorithm in each of the slots with the output of that algorithm being used to control certain of the loops or to provide input to another slot or to a control program. Control programs which can be written by the user are run sequentially in the background to provide additional loops of control or inputs to the slots so that the number of algorithms which can be used is increased without drastically increasing the equipment required.

Abstract: Apparatus for optically multiplexing the signals of several optical sensors when those sensors are of the type which utilize a single light input optical fiber for each sensor to send light to the sensor from a central monitoring station and a single signal output optical fiber for each sensor to communicate the light output of the sensor back to a single receiver in a central monitoring station. There is provided means which will sequentially introduce a predetermined amount of light flux into the sensors and thereby produce signal outputs from those sensors indicative of the magnitude of the quantities being measured. There is also provided means to communicate those outputs to a single common optical receiver.

Abstract: A photoelastic transducer is constructed with a photoelastic element receiving a 45.degree. polarized light beam with a wave plate providing a 90.degree. phase displacement in its orthogonal components. The element has reflective surface coatings to produce multiple internal reflections so as to lengthen the optical path, and increase the sensitivity of the unit. Analysis of the orthogonal outputs can be according to the difference divided by the sum with one of the outputs being multiplied by the ratio of the D.C. component of the other output to its D.C. component, for the purpose of compensating for changes in tramsmission of the two signals.

Abstract: A hydraulic control system is provided, including first and second bidirectional fluid actuated motors adapted to travel a predetermined amount in each direction. A directional control valve is placed in fluid communication with a supply of high pressure, hydraulic fluid and a reservoir and has a first operating position for directing the supply of fluid to the motors in a first direction of flow and a second operating position for directing the supply of fluid to the motors in a direction of flow opposite to the first direction of flow. A combination sequence and regeneration valve is in continuous fluid communication with the supply and the second motor for preventing the operation of the second motor until the first motor has reached its limit of travel and for regenerating fluid from one side of the second motor to the other side when the first motor has reached its limit of travel and the control valve is in its second operating position.