Abstract: An air flow measurement device includes a connector conduit for the air flow having a transverse restrictor plate located therein with a plurality of uniform and uniformly spaced apertures extending therethrough. The restrictor plate is maintained in the connector conduit by a pair of sleeves each of which includes on its interior diameter a plurality of angularly spaced passages and on its outer diameter a circumferential groove communicating with the passages. A pair of valves are mounted through the wall of the connector conduit for communication with the circumferential grooves so that a differential pressure meter may be connected to the valves to measure the difference in pressure upstream and downstream of the restrictor plate to thereby determine the flow rate. The sleeves may be made in two identical pieces to form the passages and grooves, and additional smoothing screens may be positioned upstream and downstream of the restrictor plate by further identical sleeve pieces.

Abstract: A circuit for generating a linear current proportional to the displacement of the movable member of a transducer receives an undetermined supply voltage from a monitoring circuit which has a relatively high internal resistance. The circuit is provided with two parallel current paths with one path including a resistive potentiometer strip and other path including a transistor and resistor connected in series. The movable member of the transducer has an electrical contact member attached thereto with the contact member having one end making contact with the resistive potentiometer strip and with the other end thereof making contact with a conductive strip which is connected to the gate of the transistor so that the current drawn by the circuit will be linearly related to the movement of the movable member.

Abstract: A gas flow meter includes a cylinder closed at its upper end and slidably supported within a bearing ring. The cylinder side wall is provided with openings. A gas flow is directed into the interior of the cylinder which causes it to rise with respect to the bearing ring and permitting the gas to flow out of the area of the openings exposed above the bearing. During a constant flow of gas through the cylinder the flow rate can be measured by the distance which the cylinder has moved upwardly as indicated on a fixed marker positioned adjacent to the cylinder. An electrical signal is also provided by means of an electrical sensor positioned axially within the cylinder.

Abstract: An improvement in the test for air leaks of an air pressurized telephone cable is disclosed. The cable is of the type wherein a number of individually insulated conducting electrical strands are surrounded by a protective plastic tubing impermeable to water and maintained dry under air pressure. The cable is typically buried. The improvement comprises a capillary flow controller for the introduction of trace gas, such as helium into the cable. The trace gas is introduced into the system at a pressure exceeding twice and preferably 10 times the ambient dry air pressure within the cable. The capillary introduces the high pressure trace gas to the interior of the cable by leaking a relatively constant volume flow rate to a discharge chamber.

Abstract: A calorimetric load for very high microwave power at very high frequencies is formed by a metallic, cylindrical chamber into which the wave-guide carrying the power opens. Inside the metallic cylinder is a coaxial dielectric cylinder, with a space between full of circulating wave-absorbing fluid such as water. The incoming wave may be in a higher-order mode. To make it disperse rapidly into the absorbing fluid, a conical reflector is located inside the dielectric cylinder to reflect the wave outward.

Abstract: Apparatus for processing a composite noise signal containing sonic and ultrasonic components generally in a frequency range of about 20 Hz-100 KHz to make audible both components of the signal includes a heterodyne circuit operable in response to a rectangular wave local oscillator signal to produce output signals which are within the frequency range of human hearing.

Abstract: A transducer unit comprised of a pair of transducers coupled together in a manner such that the offsets, drifts and the like of the circuit elements of one transducer are opposed by and cancelled out by the circuit elements of the other transducer. The transducers can be in the form of Wheatstone bridges and each of the branches of the bridge contains a circuit element of each transducer, respectively, the circuit elements of the branches of the transducer unit being in opposition to each other so as to cancel out the effects due to temperature, acceleration, aging and the like.

Abstract: An improved flow meter has a vertical chamber of relatively constant cross-section. In this chamber a float resides having a corss-section only slightly less than the cross-section of the chamber. Fluid is introduced at the bottom of the chamber and flows to the top of the chamber. The chamber top is provided with relief port outletting through a chamber throttle value. Similarly, a passage through the float has a float throttle valve. The chamber throttle valve controls the back pressure on the float and provides adjustability to the lifting of the float at various pressure levels. The throttle valve provides adjustability to the range of flow to which positioning of the float responds. A series of apertures configured along the sides of the chamber open as the float moves upwardly in response to increasing fluid pressure in the chamber below the float. The flow meter is digitally sensitive on an analog basis to changes in flow.

Abstract: A sensor for use on the front end of a flexible, resilient probe for use in an underground duct of the type which contains one or more current-carrying cables. The sensor is provided with a signal generating device for detecting a particular operating condition of a cable in the duct when the sensor moves through the duct adjacent to the cable. In one embodiment of the sensor, acoustical signals are sensed by a crystal when such acoustical signals originate from a leak in the pressurized sheath surrounding the cable. In another embodiment of the sensor, a coil senses the magnetic field surrounding the cable so that electrical shorts occurring in the cable can be monitored. In a third embodiment of the sensor, a heat detector is provided so that the sensor can detect hot spots in a duct.

Abstract: A circuit having a transducer which normally provides a non-linear output as a function of a stimulus to which the transducer is responsive. The circuit is provided with a feedback resistor from at least one of a pair of output terminals coupled to the transducer, and the feedback resistor is coupled to the power input of the transducer. Any change in the output voltage will cause a current change through the transducer, and this current change has a linearizing effect on the output voltage. The circuit is especially adapted for use with a Wheatstone bridge having a power amplifier coupled to the input thereof and a differential amplifier coupled to the output thereof. In such a case, a pair of feedback resistors couple the output terminals of the differential amplifier with the input terminals of the power amplifier.

Abstract: A differential amplifier suitable for use with a transducer network, such as a Wheatstone bridge, for measuring small signal voltages while eliminating common mode voltage contributions applied to the input of the amplifier. A potentiometer is connected across the output terminals of a pair of amplifiers whose positive input terminals receive the common mode voltage components and induced signal voltages from the transducer network. The shiftable terminal of the potentiometer is connected to the negative input terminals of one of the two amplifiers and adjusted to control the gain of the amplifier pair. The output signals of the differential amplifier are proportional to the induced signal voltages and devoid of the common mode voltage.

Abstract: A duct probe having a coaxial cable is provided to advance a microphone through an underground or other duct containing a cable in a pressurized sheath for sensing fluid leaks in the sheath. The coaxial cable is embedded in a resilient fiberglass rod of one-piece construction. The rod is sufficiently flexible so that it can be wound onto and unwound from a reel having a cage-like configuration. A stationary base is provided to rotatably mount the reel, and the base is provided with a length measuring device responsive to the movement of the duct probe as it is unwound from the reel so that the distance by which the duct probe penetrates a duct can be determined. At the outer end of the rod, a microphone is mounted for sensing the sounds caused by a fluid leak in the pressurized sheath in the duct.

Abstract: Multi-component motions between two parts are sensed by this apparatus which comprises a first conductive element and a plurality of second conductive elements with a frame connected to the first and second elements to hold them closely spaced from each other but not in electrical contact. An electric oscillator is connected between the first element and the second elements to apply an oscillating signal between the first element and each of the second elements. A sensing circuit is connected to each of the second elements to separately detect changes in the protential between the first element and each of the second elements as the two parts are moved relative to each other and to produce a first set of separate electrical signals representative of such changes in the potential.

Abstract: A remote volume flow meter is disclosed in which a variable density optical filter attached to a moving diaphragm indicates flow by filter position. The diaphragm has a hole, which hole travels along a needle. The needle is mounted to the housing via a needle stem. Excursion of the diaphragm at the hole occurs against a spring force. Upon movement against this spring force the diaphragm hole sees a changing area defined by the needle. Typically, the needle is of overall cylindrical configuration with one or more linearly tapering grooves extending from one end of the needle to another end of the needle. These grooves taper from a small interruption of the cylindrical cross-section at the low mass flow rate end of the needle to a large interruption of the cylindrical cross-section of the needle at the high mass flow rate end of the needle. Centrally of the needle and protruding to the high flow rate end of the needle there is provided a threaded adjustment needle.

Abstract: A pair of spaced apart grooves are machined in a plate in correspondence with the movement of a patient's left and right condyles relative to the sockets in which they move. A third groove is also machined in the same plate, equally spaced and remote from the pair of grooves, in correspondence with the minimal separation of the patient's mandibular and maxillary teeth at various lateral and anterior positions. The plate is then attached to a cast of the patient's maxillary teeth and is mounted in an articulator frame on rigid posts which slide in the machined grooves of the plate as the plate is manually moved, thereby reproducing movements corresponding to the patient's closure pathway and condylar topography.

Abstract: A gas analyzer is disclosed which responds to the resonant absorption or emission spectrum of a specific gas by producing an acoustic resonance in a chamber containing a sample of that gas, and which measures the amount of that emission or absorption by measuring the stength of that acoustic resonance, e.g., the maximum periodic pressure, velocity or density achieved. In the preferred embodiment, a light beam is modulated periodically at the acoustical resonance frequency of a closed chamber which contains an optically dense sample of the gas of interest. The light beam is introduced into the chamber through a window transparent to the radiation in the spectral band of interest and located at a position in the chamber which can support a pressure maximum during acoustical resonance of the gas within the chamber. Periodic heating of the absorbing gas by the periodically modulated light beam incident on the gas then causes a cyclic expansion, movement, and pressure within the gas.

Abstract: A self-calibrating radiometer comprising a block having a front surface for receiving incident radiation flux, an identically configured rear surface for receiving internally applied heat and a midportion for thermally insulating the rear surface from the front surface, the front surface being capable of absorbing as heat substantially all radiation flux incident thereupon and capable of reradiating substantially all of the absorbed heat, and the rear surface being capable of radiating substantially all heat applied thereto, a thermocouple configuration for sensing the heat radiated by each of the front and rear surfaces, an indicator for indicating any difference in the sensed heat, a heating element for applying enough heat to the rear surface so that no difference in heat radiated by the front and rear surfaces is indicated by the indicator, and a measuring circuit for measuring the heat applied to the rear surface, such measurement being indicative of the radiant flux incident on the front surface.

Abstract: An apparatus is disclosed for regulating the flow of solution from a fluid reservoir to the vein of a patient. All of the embodiments of the present invention include a first fluid chamber having an inlet and a discharge port and means disposed within a first fluid chamber for maintaining the level of solution therein between upper and lower levels. In all of the embodiments of the present invention, an upper and lower valve seat is provided within the first chamber which interacts with a float or floats contained therein to from two valve mechanisms which maintain a constant rate of flow of solution independent of the initial height or variations in height of solution contained within the reservoir during its depletion. In two of the embodiments of the present invention, a second fluid chamber is coupled to the first fluid chamber by means of a drip chamber which permits the visual counting of the rate of flow of solution from the first chamber to the second fluid chamber.

Abstract: High efficiency, multi-dimensional thin film vacuum tubes suitable for use in high temperature, high radiation environments are described. The tubes are fabricated by placing, as by photolithographic techniques, such as are used in solid state integrated circuits, thin film electrode members in selected arrays on facing interior wall surfaces of an alumina substrate envelope. Cathode members are formed using thin films of triple carbonate. The photoresist used in photolithography aids in activation of the cathodes by carbonizing and reacting with the reduced carbonates when heated in vacuum during forming. The finely powdered triple carbonate is mixed with the photoresist used to delineate the cathode locations in the conventional solid state photolithographic manner. Upon high temperature forming (1000.degree. C) the barium, etc. is formed at the surface. Anode and grid members are formed using thin films of refractory metal.

Abstract: A non-dispersive gas analyzing apparatus is described having a first chamber for containing a first gas, the density of which it is desired to determine. A source of radiant energy is provided for passing radiant energy through the first chamber. Modulation means are provided for modulating the radiant energy passing through the first chamber by modulating the volume of the chamber at the acoustic resonance frequency of the first gas and the chamber. Signal generating means including a second chamber for containing a gas which is heated by radiant energy emerging from the first chamber and a microphonic means responsive to the resulting pressurization in the second chamber is provided for generating a signal having a frequency and amplitude corresponding to the modulation of the radiant energy in the first chamber.