Abstract: A small volume prover is disclosed which is compact and capable of obtaining highly reliable measurement, keeping a highly accurate base volume without being affected by temperature and pressure of fluid to be measured.The prover includes a cylindrical outer housing having a fluid inlet and a fluid outlet spaced apart from each other, a cylindrical measuring conduit having both open ends and first and second sets of fluid ports radially made in a wall thereof and coaxially mounted within the outer housing and an annular wall mounted between the outer housing and the measuring conduit at the position between the measuring conduit open end and the first set of ports thereof to form an upstream annular passage and a downstream annular passage. During proving preparation a piston is restrained by a piston actuator provided in the outlet-side end of the outer housing to permit the fluid to pass through the annular passage.

Abstract: A flowmeter proving apparatus for obtaining a reliable flow meter factor in a short time, using a flow-meter having a non-uniform pulse output with a small volume power. The flowmeter to be proved is connected in series with a small volume prover, using a by-pass valve. A CPU calculates irregularities of meter pulse spacing, determines the repeatability for a proving run from the number of counted meter pulses and a function given by the meter pulse number and the meter pulse space irregularity. The CPU then computes the proving pass number N.sub.p necessary for obtaining the required repeatability by substituting the repeatability value into another predetermined function.

Abstract: A heat-conductive stream pipe has an upstream side and a downstream side temperature-sensing element having resistance wires wound round the pipe at a certain distance there-between to assure that there will be no thermal influence with each other. A control means controls a bridge circuit including a ground point at one end and a connecting point at the other end of each of the temperature-sensing elements so as to keep the temperature difference between the upstream side and the downstream side temperature-sensing elements at a constant level. An adjustable auxiliary heater is placed on the stream pipe at the downstream side near the downstream side temperature-sensing element. The mass flow of the fluid is determined by the voltage measured at the connecting point of the downstream side temperature-sensing element.

Abstract: A vortex flowmeter wherein a main body and a fitting plate with a by-pass are integrally formed with each other and the fitting plate placed an an outlet of a passage of small diameter and of a constant section extending from an inlet of a large diameter with a continuous contraction. The passage in the main body includes a vortex generator and a vortex sensing means for detecting a vortex produced by the vortex's generator. The by-pass line is composed of a plurality of round through-holes arranged in a circular portion of the fitting plate.

Abstract: A calorimeter comprises a laminar flow type flowmeter for measuring the volume of flow of a fuel gas as a value proportional to the difference between the pressures of the laminar flow elements and a stream pipe serially connected to the laminar flow type flowmeter to create a laminar flow therethrough. The stream pipe is provided with a heating means, a temperature sensing means for detecting the difference between the temperatures of the fuel's flow to and from the stream pipe portion heated by the heating means, and a thermal-type flowmeter for measuring a mass flow proportional to the differential temperature sensed. A computer unit calculates the outflow pressure and the volume of flow of the fuel gas in its normal state from the measured values of the absolute pressure, the differential pressure and the temperature of the fuel gas flowing into the laminar flow-type flowmeter and calculates the calorific value of the fuel gas as a value that is negatively proportional to the differential pressure.

Abstract: A vortex flow meter having a vortex generator comprises a plurality of vortex generating elements installed in a fluid passage perpendicular to the fluids flow. An upstream-side vortex generating element and a downstream-side vortex generating element are both arranged in parallel at a predetermined interval therebetween in the direction of the fluid's flow. Zero to plural flat plates are arranged in parallel at equal intervals between both vortex generating elements. The representative length portions of the vortex generating elements are located respectively on the surfaces opposed to each other. The frequency ratio of the vortexes generated, when independently arranged, are 0.7 to 0.9 on the standard basis of the upstream-side vortex generating element.

Abstract: An ultrasonic fuel injection nozzle comprises a generator for generating ultrasonic vibrations, a vibrator secured to the ultrasonic vibration generator and a valve for supplying fuel to the vibrator. The vibrator is secured to the ultrasonic vibration generator at one end and is formed with a cavity in its other end portion for atomizing fuel therein. The vibrator has a fuel passage communicating with the interior of the cavity. A valve is provided for normally closing the passage and for opening the passage to discharge an amount of fuel depending upon the passage opening duration. A fuel atomizing portion serves to reduce the discharged fuel to minute particles through the effect of ultrasonic vibrations.

Abstract: A Karman vortex flow meter comprises a vortex generating post 4 disposed in a fluid conduit 1, a plurality of ultrasonic wave transmitters 6a, 6b provided in a wall of the conduit downstream of the post, and an ultrasonic wave receiver 8 provided in a wall of the conduit opposing the transmitters. The transmitters are either juxtaposed at a horizontal sectional face of the conduit and generated ultrasonic waves simultaneously toward the receiver, or they are provided in series in an axial direction of the conduit while the receiver is provided opposite the transmitter on the downstream side. In the latter embodiment the transmitters are connected to a change-over circuit which switches from the downstream transmitter to the upstream one when the detected frequency of the Karman vortex streets in the fluid exceeds a predetermined value.

Abstract: The present invention relates to an elastic tubing pump and more particularly to an elastic tubing pump. The pump has an elastic tube communicating with a liquid supply source, a pressing means for pressing at least two points of a section of the elastic tube to seal the liquid therein, a driving means for pushing the pressing means in one direction of the elastic tube, a locking means for firmly holding the elastic tube from being moved by the pressing means, a shifting means for unlocking the locking means according to the driving operations of the driving means and for advancing the elastic tube by the length of its compressed section. The driving means can accelerate to compensate for the possible decrease in the liquid's flow through the tube during a time of shifting the elastic tube by one section's length.

Abstract: A vortex flow meter having a vortex generator comprises a plurality of vortex generating elements installed in a fluid passage perpendicular to the fluid's flow. An upstream-side vortex generating element and a downstream-side vortex generating element are both arranged in parallel at a predetermined interval therebetween in the direction of the fluid's flow. Zero to plural flat plates are arranged in parallel at equal intervals between both vortex generating elements. The representative length portions of the vortex generating elements are located respectively on the surfaces opposed to each other. The frequency ratio of the vortexes generated, when independently arranged, are 0.7 to 0.9 on the standard basis of the upstream-side vortex generating element.

Abstract: A vortex flow meter having a vortex generator comprises a plurality of vortex generating elements installed in a fluid passage perpendicular to the fluid's flow. An upstream-side vortex generating element and a downstream-side vortex generating element are both arranged in parallel at a predetermined interval therebetween in the direction of the fluid's flow. Zero to plural flat plates are arranged in parallel at equal intervals between both vortex generating elements. The representative length portions of the vortex generating elements are located respectively on the surfaces opposed to each other. The frequency ratio of the vortexes generated, when independently arranged, are 0.7 to 0.9 on the standard basis of the upstream-side vortex generating element.

Abstract: A vortex flow meter is comprised of a vortex generator provided in a fluid to be measured and a tube member installed in a direction intersecting with it at the downstream side. The tube member includes at least a couple of holes arranged at intervals of predetermined distances in the direction of the shaft. A pressure variation due to the Karman vortex created by the vortex generator is applied to the fluid in the tube member through the above-mentioned holes. A detector for sensing the pressure variation is installed in the tube member. The number of Karman vortexes is counted by the pressure variation detector.

Abstract: A vortex flow meter includes a bluff body which sheds a vortex train when a fluid flowing in a conduit moves therepast, the vortex train developing a delicate pressure variation in proportion to a flow rate of the fluid. The flow meter detects the flow rate by sensing the pressure variation and then converting it into an electric signal by means of a piezoelectric element or the like. A pressure sensor is detachably mounted in a pressure sensing chamber, which is defined in an internal space of the bluff body, and comprises a pressure receiving plate displaceable in response to the pressure variation, a sensor member such as a piezoelectric element for converting the displacement into an electric signal. The pressure receiving plate is arranged such that major part thereof is located in the conduit, while major part of the sensor member is located in a wall of the conduit and the outside thereof.

Abstract: A vortex flow meter includes a vibration sensing element having a sensor responsive to an external vibration and a sensor responsive to a vortex train at vertically opposite ends thereof. The sensing element is fixed to a conduit fulcrumed at an intermediate portion thereof. A vortex shedding member is integrally and oscillatably mounted in a lower portion of the sensing element. The flow meter can be assembled merely by being positioned in the conduit and, due to an integral structure, it is effectively applicable even to small diameter conduits through which fluids flow at very small flow rates. In a path along which leads from a sensor responsive to pressure variations due to vortex trains are routed to a transducer box, vibration of the transducer box is prevented from reaching the sensor via the leads, thereby rendering the flow meter less susceptive to externally derived vibrations.

Abstract: In a vortex flow meter for measuring a varying flow rate of a fluid through a conduit, an oscillation compensating apparatus is constructed to remove undesirable externally derived oscillation noise which is applied to the flow meter. An elongate vortex shedding member extends into the conduit through part of its wall. The shedding member forms a shedding portion inside the conduit and a compensating portion outside the conduit. The shedding portion carries a first oscillation sensor therewith and the compensating portion, a second oscillation sensor. The first sensor is sensitive to an oscillation component caused in the shedding portion by a vortex train shed in the conduit, and an externally derived oscillation noise component. The second sensor is sensitive to the noise component only. All these sensed components are combined to cancel the oscillation noise so that only the oscillation component in the shedding portion is picked up.

Abstract: A piezoelectric sensor for measuring an external force is disclosed which is accommodated in a cassette through a sealing member and provided with a pair of electrodes which are respectively bonded to opposite sides of a piezoelectric element. A masking strip made of a highly insulative material covers the whole area of and end face of the piezoelectric element, which is exposed to the outside of the sensor, and a desired width of an end face of each of the electrodes adjacent to the end face of the piezoelectric element. This maintains a high resistance between the electrodes having the piezoelectric element therebetween and thereby promotes accurate measurement without being effected by changes in the resistance of the sealing member due to temperature variation. The sensor is effectively applicable to a vortex flow meter.

Abstract: A fluid conduit with a rectangular cross-section is divided into two parallel conduits. A vortex generating rod is disposed perpendicularly to the flow direction in one of the conduits. An ultrasonic wave is directed perpendicularly across the conduit to detect the Karman vortex streets. A sound absorbing material is located along the portion of the conduit wall where the ultrasonic waves exist for preventing the formation of standing waves.

Abstract: A gaseous fluid flow meter utilizing a Karman vortex street has a conduit having opposed flat walls and through which a gaseous fluid to be measured flows, a vortex generating member disposed perpendicularly to the direction of flow of the fluid to generate the Karman vortex street downstream thereof, a vortex detector disposed on the conduit and having a transmitter in one flat wall for transmitting a continuous ultrasonic wave across the Karman vortex street and a receiver in the other flat wall positioned opposite the ultrasonic wave transmitter in a direction perpendicular to the direction of the flow of the gaseous fluid through the conduit for receiving the continuous ultrasonic wave to detect the changes in phase of the ultrasonic wave indicating the number of vortices of the Karman vortex street generated in a unit time, and a sound absorbing material on only the portion of the inner surfaces of the flat walls of the conduit around the transmitter and around the receiver and extending sufficiently far

Abstract: The present invention relates to a positive displacement flow meter having a pair of rotors to be rotatably engaged with each other which are provided with tooth profile curves of a cycloid and of a trochoid.Since the tooth profile of one rotor is equal to that of the other rotor, transmission of energy between the two rotors is uniform, and wear of teeth of the two rotors being reduced.