Abstract: Apparatus for switching a fluid stream, either gaseous or liquid, between a first path and a second path is disclosed. A pair of enclosures are formed by two depressions in a first plate (each depression having an inlet and an outlet) and an elastomeric diaphragm covering the depressions. The diaphragm is held in place by a second plate having a first control inlet opposite one depression and a second control inlet opposite the other depression. A fluid to be switched is connected into the inlets of the first plate in common. By alternately applying a control fluid to one control inlet and then the other of the second plate, the fluid to be switched is switched from one outlet to the other by the diaphragm alternately being deformed into one depression and then the other by the control fluid so as to seal the inlet and outlet and, thereby, block the flow of fluid therethrough from the inlet to the outlet.

Abstract: An improved electrode for use in oxygen determination is disclosed. Interference from carbon dioxide is eliminated by combining an improved electrolyte with means for permitting rapid electrolyte movement into and out of the space between the cathode and the membrane covering the cathode to maintain the pH of the electrolyte in the space substantially constant. The electrolyte consists of a KCl solution containing KOH of from 0.1 to 2%.

Abstract: An improvement to a misfire monitor sensing lean-roll in an internal combustion engine by comparing the rate of change in O.sub.2 in the exhaust gases with respect to time against a limit is disclosed. In the preferred embodiment, the sensed O.sub.2 level in the exhaust is used as an input to rescaling means which automatically normalizes the values used in the comparison to a standard range. Normalization is accomplished alternately by rescaling the rate of change value, rescaling the limit value used, or diluting the exhaust gases sampled to the level of a "standard" air blown engine to which the comparison limit is scaled.

Abstract: Exhaust gas diagnostic apparatus capable of use on both catalytic converter equipped and non-catalytic converter equipped motor vehicles is disclosed. A fast response oxygen analyzer is coupled with means for differentiating the signal output of the oxygen analyzer. In this manner, both the quantity and rate of change of oxygen in the exhaust gas is made available to apparatus included therein for indicating and/or alarming quantity and rate of change values outside preset limits. The apparatus is particularly directed to the detection of an engine misfire condition. The apparatus disclosed permits diagnosing problems without disconnecting the air injector system (if present) or having a port prior to the catalytic converter. As it alarms on transients, it is independent of the steady state oxygen level.

Abstract: A semiconductor material is doped or alloyed under vacuum with an impurity by thermal decomposition and by sedimentation resulting from centrifugal force. The doping material is alternatively applied by evaporation before being subjected to centrifugal force and may be heated up to the melting point before completion of the centrifugal action. A centrifuge is provided having a thermal insulating layer between the outer wall of a rotor and a support for basic semiconductor material to be doped. The doping impurity material to be evaporated onto the basic solid state material is placed in the center of the centrifuge rotor.

Abstract: A set point adjust mechanism is disclosed for use with process controllers to manually adjust the set point value and simultaneously change the set point value indicated. The set point adjust mechanism includes a manually actuable thumbwheel and an idler wheel mounted in contact with each other on a slider. Thumb pressure on the thumbwheel causes the slider to move so that the idler wheel contacts an indicator drive wheel. The set point value source, usually a potentiometer, is connected to the indicator drive wheel which also drives a belt that positions a pointer with respect to a scale. The pointer and scale provide the set point indication. When the pointer hits a pointer stop, or for any other reason resists motion, further rotation of the thumbwheel causes the idler wheel to move to engage a mechanical stop to prevent further thumb pressure from causing dislocation between the indicated set point value and the set point value source.

Abstract: An amplifier capable of operation in four modes singly or in combinations is disclosed. The modes are: DC amplification mode, AC amplification mode, suppressed baseline mode, and offset correction mode. In the DC amplification mode, the amplifier operates as a conventional DC amplifier. In the suppressed baseline mode, the outputs of the input and output amplifiers are connected back to their input stages through a long time constant integrator resulting in the suppression of any DC output voltage. In the AC amplification mode an RC decoupling network is inserted in the inputs to the input amplifier means to pass AC signals and reject DC components. In the offset correction mode, the inputs of the input and isolator amplifier means are shorted to create zero differential at the summing junctions thereof. Any offset voltage present at the output of the input amplifier means or output amplifier means is suppressed by means of integrated feedback to the input stage of the input and output amplifier means.

Abstract: Improved apparatus for bringing a fluid in a process stream in contact with a sensor is disclosed. The present invention uses the kinetic energy of the process fluid to convey some of the fluid to and from the sensor, as opposed to the prior art practice of inserting the sensor itself into the process fluid stream. A nozzle is placed into the process fluid stream facing into the direction of flow. A small portion of the flowing process fluid is trapped by the nozzle and some of its kinetic energy is converted to pressure. This pressure causes a flow from the nozzle into a conduit through an open valve to the sensor. The fluid continues past the sensor and returns to the process fluid stream through the same valve. In one embodiment, the path for incoming fluid and exiting fluid are separate paths. In a second embodiment, the incoming fluid and exiting fluid exist coaxially.

Abstract: Method and apparatus for generating a sweep signal for the oscilloscope of an engine ignition analyzer, employing a lock loop with phase detector, integrator and voltage controlled oscillator. The oscillator provides a ramp voltage for use as a sweep signal. A feedback circuit provides a feedback signal to the input of the phase detector when the ramp voltage reaches a predetermined value for phase comparison with a reference signal related in time to an engine ignition event. The intetrator output controls the slope of the ramp voltage. When the two input signals to the phase detector are out of phase, the slope of the ramp voltage is changed via the integrator to reduce the phase difference. The ramp voltage provides a sweep signal of substantially constant length while the engine speed varies over the range of idling to full speed.

Abstract: A timing control circuit for a strobe lamp for use in adjusting the timing of an internal combustion engine. A circuit which provides for retarding lamp triggering for setting ignition advance and for advancing lamp triggering for setting ignition retard. A circuit providing for advance and retard selection, the amount of advance or retard, and zero degree triggering for engines with various numbers of cylinders. A circuit with a ramp voltage synchronized with engine timing, a reference voltage for setting the amount of advance or retard, and a comparator which provides a triggering signal for the lamp when the ramp and reference voltages match.

Abstract: An automobile engine ignition analyzer with engine performance displayed on an oscilloscope. Circuitry for providing timing indicia on the oscilloscope trace in the form of high intensity spots or gaps, with the time intervals between indicia maintained constant as engine speed varies. A pickup for coupling the engine ignition pulse to a pulse shaping circuit which provides an output pulse related in time to the ignition pulse, and an oscillator started by the output pulse and providing a train of pulses at predetermined intervals, typically one millisecond, with the pulse train connected to the oscilloscope beam intensity control for blanking or intensifying the beam as desired.