Abstract: A transducer housing assembly for an ultrasonic flowmeter made by an injection molding having a pair of pedestals for supporting the transducers at a specific angle while acoustically isolating the transducers from each other and providing an air backing for the transducers to improve the sensitivity of the transducer assembly.

Abstract: A preamplifier circuit for a voltage measuring instrument which provides for noninteracting span and zero adjustments. Two voltage follower circuits are used. The first produces a current through the output resistor of the preamplifier proportional to the voltage being measured while the second produces a current through the output resistor proportional to a fixed reference voltage. For both amplifiers, the proportionality is adjustable by a potentiometer which modifies the feedback on the first amplifier and the part of the reference used as input to the second amplifier.

Abstract: An ultrasonic Doppler flowmeter for measuring flowing fluid by reflection of sonic waves from particles in the fluid is provided with a discriminating circuit including a comparator amplifier connected to the received signal that produces a zero-flow output from the flowmeter when the signal received by the receiving means is produced by vibration of the reflecting particles in a zero-flow condition.

Abstract: A boiler control system for boilers fired by solid fuels wherein the fuels are carried through the combustion zone of the boiler on a traveling grate and wherein the air flow for combustion as supplied to the undergrate region utilizes a control of the fuel rate from a deviation of the outlet pressure from the desired value with the control of the air flow to the undergrate region maintained generally in proportion to the steam flow from the boiler with the proportionality being biased from the deviation of the outlet pressure from its desired value.

Abstract: An expendable phase change detector device is provided with an initial coating on the twisted wire forming the thermocouple junction which is, in turn, covered by a refractory coating during the manufacture of the device. The initial coating responds to an increased temperature to ablate the refractory coating from the thermocouple junction when molten metal is poured into the device.

Abstract: A control system is provided for turbines in the utility part of an industrial plant using cogeneration so that control is maintained over the relative quantities of steam supplied to a common steam header from both the back pressure and the extraction turbines where the header supplies process steam at a predetermined pressure. The steam flow from a stage of the extraction turbine is controlled to maintain the header pressure at its desired value. The steam flow thus controlled is measured and a control means is provided to control the steam flow from a back pressure turbine supplying the same header so as to maintain a predetermined relationship between the two steam flows while maintaining electrical generation from the generators driven by the turbine at a maximum consistent with maintenance of an adequate control range for the header pressure control.

Abstract: A rectangular sample cell for use in the measurement of the light scattered from an incident light beam in three mutually orthogonal directions is constructed with a prism having its base optically in contact with the sample along a side of the cell. Two other faces of the prism are oriented at equal angles to the base so that those faces pass orthogonal components of the light scattered at 90.degree. from the axis of the incident beam. The other orthogonal component is formed by the forward scattered light.

Abstract: Apparatus for wiping the optical window of a sample cell in a turbidimeter or other particle measuring instrument for analyzing a liquid sample. The wiping apparatus is operated by the pressure of the source of supply of the liquid sample and avoids the necessity of liquid seal bearings.

Abstract: Boiler outlet temperature in a sliding pressure operation is controlled in a routine way by varying the fluid or heat distribution in the boiler. The effect a change in pressure has on steam temperature is anticipated by supplying a feedforward signal to the temperature control system from drum pressure so as to minimize temperature variations at the boiler outlet.

Abstract: A resistance thermometer probe assembly is constructed by locating a header assembly in the end of a cylindrical sleeve. The header is constructed as a stack of discs. The disc exposed to the environment is of stainless steel and the disc supporting the thin film resistance thermometer chip is of ceramic. A copper disc is brazed between the ceramic and the stainless steel to accommodate the different thermal coefficients of expansion. Nail-head pins are brazed to a thick film deposit on the exposed face of the ceramic disc and the resistance thermometer chip is connected electrically between the pins.

Abstract: There is provided a method for measuring a parameter whose value is calculable as an integral with time of a function of at least one variable so as to make possible the use of a microprocessor when measurements of such variables are desired. The variable is sampled periodically at a frequency asynchronous with the wave form which the variable follows and then there is periodically calculated the value of the function by summing the values for the function determined by the samples taken during the time between the calculations, thus determining the desired integral.

Abstract: An expendable immersion thermocouple having a cup-shaped body member for supporting the thermocouple and providing a cavity into which a refractory cement is poured to secure the thermocouple in place. The refractory cement is nonhomogeneous and has a surface region which is substantially composed of a high temperature refractory material such as alumina.

Abstract: A method and means for controlling the throttle pressure of a fuel fired drum type boiler by controlling the fuel input to the boiler so as to equalize the boiler demand, calculated as the product of a quantity proportional to the rate of energy output from the boiler at the existing throttle pressure times the ratio of the desired throttle pressure to the existing throttle pressure, and the heat released to the boiler by the fuel, calculated as the sum of a quantity proportional to boiler output and the measured rate of change of drum pressure.

Abstract: An ultrasonic Doppler flowmeter in which the transmitting and receiving transducers are located in a head that is secured to the outer surface of a pipe through which the fluid to be measured flows. The head includes a thermistor responding to the temperature of the head to temperature-compensate the flow indication of the flowmeter. The Doppler-shifted received frequency is added to the transmitted frequency and the envelope of the resulting signal detected and amplified. The Doppler signal is shaped and used to switch on a current source for a fixed time interval at a rate dependent upon the Doppler frequency. The thermistor located in the transducer head varies, in accordance with temperature, the magnitude of the switched current. The switched current is integrated and used to supply the signal to the output meter.

Abstract: In a power distribution system comprising interconnected distribution areas which includes a jointly owned unit, that jointly owned unit is controlled to allocate regulating outputs for the areas participating in the joint ownership in accordance with the percentage of ownership, the amount and direction of change in generation requested by the participating areas and the rate limited capability of the unit.

Abstract: The displacement of the diaphragm in a differential pressure sensor of the differential capacitor type produces an output signal substantially linearly related to the displacement. The capacitors are charged in parallel from a constant current source for a fixed period of time and discharged through separate discharge circuits for another fixed period of time. An integrating differential amplifier connected to the two capacitors as they discharge produces an output signal related to the area between the two discharge curves which is substantially linearly related to the extent of displacement of the diaphragm of the differential pressure sensor. The output from the amplifier is used to control the current output from the device.

Abstract: The membrane of an ion selective electrode is tested for damage while it is being used for continuous measurement by sending a test current through the electrode system and measuring the voltage change produced. If the voltage change does not reach the value expected with an intact high resistance electrode, a defective electrode is indicated. A reverse current of the same magnitude and duration is then sent through the electrode system.

Abstract: An ultrasonic Doppler flowmeter is provided with a frequency-to-voltage converter comprising a pair of interconnected filp-flops triggered by the Doppler frequency and a submultiple of the transmission frequency which produces a series of output pulses having a repetition rate determined by the Doppler frequency and a pulse duration inversely related to the frequency of transmission of the ultrasonic transmitter.

Abstract: An expendable immersion thermocouple having a ceramic body member and a plastic tailpiece for supporting the thermocouple and producing a cavity into which a refractory cement is poured to secure the thermocouple in place. The tailpiece is provided with axially-extending resilient arms with enlarged end portions to serve as latching devices to temporarily hold the tailpiece to the ceramic body.

Abstract: Control of the throttle pressure in a drum boiler-turbine system is accomplished by controlling the rate of fuel feed with a cascade control system. When fuel feed cannot be directly measured, but is computed from boiler output, the controllers in the system are decoupled to prevent their interaction. The primary control responds to throttle pressure deviation to produce a heat release demand signal which is compared to the calculated heat release. A signal produced by summing components of the heat release calculation, namely steam flow and rate of change of drum pressure, is used to cancel out any contribution to the input to the primary controller by changes in throttle pressure resulting from disturbances in the fuel feed, which disturbances will be corrected by the secondary or fuel feed controller.