Abstract: There has been provided an improved switching circuit for an oscillographic apparatus wherein a determining wave form signal is compared with a reference level signal to provide a trigger control signal. The trigger control signal, a low level signal, is selectively gated to produce a signal in response, selectively, to the negative slope comparison or the positive slope comparison. The last-mentioned signal is then used to produce a trigger signal to trigger a sweep signal generator for the oscillographic apparatus.

Abstract: A high performance magnetic tape transport and tape cartridge. The cartridge includes coplanar hubs carrying tape rolls rotatable about fixed axes. The transport includes a pair of capstans, each mounted on its own carriage assembly with its own drive motor. The capstans have a high friction surface. The carriage assemblies are spring biased with equal force toward the front of the cartridge. When the cartridge is inserted in the transport, the capstans drivingly engage the peripheries of the tape rolls, and magnetic transducer heads in the transport engage the front face of a span of tape between the rolls. The capstan motors are driven by a servo control system. The servo system provides fully bi-directional operation, highly accurate speed control, and unprecedented tension control, both across the transducer head and in the takeup roll.

Abstract: A display apparatus is provided whereby a constant intensity of record is obtained notwithstanding substantial changes in the linear speed of the record member. The cathode ray sweep frequency is maintained at a constant rate commensurate with the highest speed of the record member. As the speed of the record member is reduced by a given factor, the number of scans of the cathode ray beam which are unblanked are reduced by the same factor.

Abstract: A high performance magnetic tape transport and tape cartridge. The cartridge includes coplanar hubs carrying tape rolls on fixed axes, a brake system which urges each hub in a direction to tension the tape when the cartridge is removed from the transport, and a pair of doors which completely enclose the front face of the cartridge when the cartridge is out of the transport and automatically open to expose the entire front face of the cartridge when it is inserted in the transport. The transport includes a pair of capstans, each mounted on its own carriage assembly with its own drive motor. The capstans have a high friction surface. The carriage assemblies are spring biased with equal force toward the front of the cartridge. When the cartridge is inserted in the transport, the capstans drivingly engage the peripheries of the tape rolls, and magnetic transducer heads in the transport engage the front face of a span of tape between the rolls.

Abstract: The recorder includes a heated stylus which is positioned across a heat-sensitive chart by a servo motor to make the stylus position follow the value of an input signal applied to a servo balancing comparing and driving circuit for the motor. A switching circuit, actuated by the pulse signal output of a pulse generator, interconnects the stylus heater, a capacitor, and a source of capacitor charging energy. The switching circuit alternately charges the capacitor from the source and discharges the capacitor into the stylus heater. This causes the stylus to produce a recorded trace on the chart having an intensity which is substantially independent of the resistance of the stylus heater over a given resistance range.

Abstract: In a twin tube recording CRT system, apparatus is provided for accurately aligning the line scan trace of the two tubes with respect to each other. The positioning voltage applied to the vertical deflection plates of the two tubes is compared in a comparator network. When a substantial identity of the compared signals is detected by the comparator network, suitable indicating devices, such as LED's, are actuated to indicate the proper alignment, without the need for visual reference to the face of the tubes. There is also provided an interrelated skew correction circuit for the two tubes wherein a sample-and-hold circuit samples the skew correction signal for the first tube at a selected point in the sweep thereof. That sampled signal is superimposed on the skew correction signal for the second tube, to effect an offset of that skew correction signal by the amount of the sampled signal of the first tube skew correction signal.

Abstract: A process controller which has at least a derivative control mode includes a comparison amplifier wherein a measured variable signal is compared with a set-point signal to produce an error signal. An auxiliary control circuit including a signal level change detector is connected to detect changes in the set-point signal. During intervals of constant set-point signal, the primary control circuit operates normally. Upon the occurrence of a change in the set-point signal, the change is detected by the auxiliary control circuit and produces an auxiliary control signal which is applied to momentarily inhibit the operation of the derivative control function of the controller.

Abstract: In a gas chromatograph assembly, a heat conducting block of relatively large mass has a plurality of cavities formed therein. One cavity houses the chromatographic column; another cavity, extending into close proximity to the first, houses a temperature sensing element; and a third cavity houses a heater. This assembly is secured to a heat transmitting base to which is also secured an explosion-proof housing which houses a detector block. The entire assembly is covered with insulation and the heater block maintains the chromatographic column and the detector block at substantially the same temperature.

Abstract: A spectrometer for monitoring a gaseous mixture detects one or more component gases of interest by converting the spectrum of the mixture at certain discrete wavelengths to binary numbers which are correlated with a stored series of binary numbers corresponding to the spectrum of a component gas of interest at the same wavelengths.

Abstract: A trace locator for identifying in a visual display the position on a recording medium of a recorded trace representing an input signal in a multi-trace recorder. The trace position may be displayed without a movement of the recording medium to enable the possible trace to be located and positioned by observing the visual display. The visual display is sequentially advanced by successive clock signals until a predetermined amplitude of an input signal to be displayed is reached. The trace location is displayed for a preset period of time after which the display is cleared prior to a subsequent display of the trace location for either the same input signal or another input signal.

Abstract: A guide for a printed circuit board has a base portion which is mounted adjacent to a printed circuit board edge connector and a guide portion hinged on the fixed portion and having a longitudinal groove for guiding a longitudinal edge of a printed circuit board to introduce a printed wiring connection edge of the board into an edge connector located adjacent to the base portion while the hinged interconnection allows the guide portion to be selectively rotated during the absence of a printed circuit board in the guide portion to cover the edge connector.

Abstract: A rotary control valve has a plug in the form of a cup shaped shell mounted on a bracket which is rotatable about an axis orthogonal to and offset from the central axis of a ring seat. This plug is connected to the rotatable actuating bracket by means of a threaded pin and nut so that the plug position can be adjusted with respect to the ring seat. Proper adjustment of the pin and nut allows the plug to be mounted in a fixed position on the bracket and enables the plug to be brought into and out of fluid tight sealing engagement with the ring seat without any bending or deformation taking place in the actuating bracket. The obtaining of this desired tight sealing engagement is aided by displacing the bracket axis from the plug center of curvature in the direction of the position occupied by the plug when in its sealing position, and by making the plug position adjustable along the bracket axis.

Abstract: A line scan cathode ray tube (CRT) recorder generates a hard copy record of a curve from stored data representing the X-Y coordinates of a series of sample points along the curve. The curve may be described mathematically by a multi-valued function. One pass of the recording media past a linear sweeping CRT beam records the entire curve in a predetermined number of recording sweeps. The distance (.DELTA.X and .DELTA.Y, respectively) between each and every X.sub.n, Y.sub.n and the next successive stored sample point X.sub.n+1, Y.sub.n+1 is determined prior to each recording sweep of the beam and these distances, .DELTA.X and .DELTA.Y, are divided by a predetermined number to give a factor interpolating the distance between successively stored data points (X.sub.n and X.sub.n+1 and Y.sub.n and Y.sub.n+1).

Abstract: A solid state pH measuring electrode having the pH measuring electrode structure formed by successive layers on an insulating substrate with an outer pH sensitive glass layer being deposited on a supporting solid electrolyte layer by RF sputtering. The reference electrode is similarly formed by depositing an outer layer of glass onto a supporting solid electrolyte layer by RF sputtering with the temperature expansion of the glass and supporting solid electrolyte structure being selected to produce a differential expansion causing random cracking of the glass layer during temperature cycling of the reference electrode. A combination structure is provided wherein the pH measuring electrode and the reference electrode are formed on opposite sides of the same electrically insulating substrate with a thermal compensating element being included in the integrated package.

Abstract: A solid state pH measuring electrode having the pH measuring electrode structure formed by successive layers on an insulating substrate with an outer pH sensitive glass layer being deposited on a supporting solid electrolyte layer by RF sputtering. The reference electrode is similarly formed by depositing an outer layer of glass onto a supporting solid electrolyte layer by RF sputtering with the temperature expansion of the glass and supporting solid electrolyte structure being selected to produce a differential expansion causing random cracking of the glass layer during temperature cycling of the reference electrode. A combination structure is provided wherein the pH measuring electrode and the reference electrode are formed on opposite sides of the same electrically insulating substrate with a thermal compensating element being included in the integrated package.

Abstract: A rotary control valve has a flexible cup-shaped diaphragm ring seat positioned within a valve chamber that has an annular seating lip portion on inner opposite side portions thereof. An annular outer portion of the diaphragm ring is retained against an annular wall of the chamber by an outer portion of a retaining ring member that is longitudinally adjustable along the inner wall of the chamber. The retaining ring has an inner rigid portion that provides a hard seat surface against which one of the annular lips is compressed into sealing, fluid tight engagement as a spherical plug of the rotary valve is simultaneously brought into sealing fluid tight engagement with the other lip. The fluid acting on an inlet side of the valve is applied by way of openings in an annular intermediate portion of the retaining member to the diaphragm ring in a direction that allows the plug and diaphragm ring to make good fluid tight engagement with one another.

Abstract: A digital computer monitoring and restart circuit monitors the presence of periodic output signals from the digital computer by a missing pulse detector. When the detector senses a missing output signal from the computer, it indicates this detection operation by an output signal representation of the fact that the computer is not operating. In response to this output signal a restart pulse is generated by a restart pulse generator and is applied to the computer to restart the computer and to reset the monitoring circuit. Concurrently, a 5-second timer circuit is started. While the timer circuit is operating over its 5-second interval, if the monitoring circuit produces another output signal indicating that the computer is not operating, the 5-second timer is stopped and another restart operation is not attempted.

Abstract: A reel motor drive system using a first and a second signal for comparing an error signal derived from a tape tension sensing transducer with a respective polarity of separate positive and negative repetitive ramp signals. Each comparator produces an output signal as a series of constant frequency, duty cycle modulated pulses having a duration equal to the time that the error signal is greater than the ramp signal being compared thereto. These pulses are used as drive signals to a reel motor through a motor power amplifier and are used to develop mutually exclusive steering signals for selecting a motor drive direction by means of a steering logic circuit. The steering signals are also applied to the motor power amplifier to select a current path through the reel motor corresponding to the desired motor drive direction.

Abstract: A differential pressure to electrical signal transmitter has a pair of barrier diaphragms and one or two central control diaphragms located between the barrier diaphragms. A chamber on the outside of one barrier diaphragm is pressurized with a first fluid, and a chamber on the outside of the other barrier diaphragm is pressurized with a second fluid. First chambers between one of the barrier diaphragms and the control diaphragm, and a first length of capillary tubing connected between the first chambers and one chamber of a remotely located sensor capsule, are filled with a first incompressible fill liquid. Second chambers between the other barrier diaphragm and the control diaphragm, and a second length of capillary tubing connected between the second chambers and another chamber of the sensor capsule, are filled with a second incompressible fill liquid.

Abstract: A communication system for repeating a data signal received on one input/output line onto one or more other input/output lines while inhibiting the data signal repetition on the input/output line having input data being received thereon. The first bit of the incoming data signal is detected to generate a control signal for a line selector latch. The line selector latch latches in response to the control signal with the appropriate incoming line identification stored therein. This stored line identification is used to control a multiplexer which selects the corresponding one of a plurality of input signal detectors connected to respective input-output lines to supply an input signal to a signal repeater. The stored line identification also generates an inhibit signal to inhibit operation of a line output driver associated with the input/output line on which the incoming data was detected.