Abstract: A cylinder stroke determination system and a method of determining a stroke of a cylinder are provided. The system includes a cylinder having a rod and a barrel, a sensing cylinder configured to operate with the cylinder, and a processor. The sensing cylinder includes a sensing cylinder base coupled to the barrel of the cylinder, a sensing cylinder rod coupled to the connecting portion of the rod of the cylinder, a photon emitter coupled to the sensing cylinder base and configured to emit a photon toward a photon target disposed at the sensing cylinder rod, and a photon receiver coupled to the sensing cylinder base and configured to receive the photon reflected from the photon target. The processor is configured to determine a stroke of the cylinder based on a time of flight of the photon from the photon emitter to the photon receiver.

Abstract: A positive displacement metering system measures the rate of travel of a free piston in a cylinder of known volume to determine the flow rate of a fluid out of the cylinder. The system may also measure and record the inlet and outlet pressures or the differential pressure between the fluid inlet and outlet. The control program positions a four-way valve which may function as an adjustable metering orifice in response to the measured flow rate and/or changes in the inlet and outlet pressures to achieve the desired flow rate. At the end of each stroke, the four-way valve is repositioned to reverse fluid flow through the metering cylinder. The system may revise the valve position settings for both forward and reverse strokes based on the measured time required for a full stroke of the piston within the cylinder at a certain valve position or a measured rate of movement of the free piston.

Abstract: Provided is a calibration method for flowmeters in a blood dialysis system, whereby highly accurate calibration can be performed even by omitting a reference flowmeter not directly relating to dialysis therapy. This calibration method comprises: while preventing outflow into a blood channel in a blood purifier, supplying a liquid to a channel, said channel passing through an inflow flowmeter and an outflow flowmeter; and then calibrating the inflow flowmeter and the outflow flowmeter correction whereby, at the time of liquid supply, a value measured by the outflow flowmeter is equalized to a value measured by inflow flowmeter.

Abstract: An ultrasonic displacement measurement system for hydraulic accumulators (3) has a movable separating element (5) separating two media chambers (9, 11) from each other in a media-tight manner within a housing (7). One media chamber (9) holds a compressible fluid or an incompressible fluid. The other media chamber (11) holds a compressible working gas. The particular position of the movable separating element (5) within the housing (7) can be detected by an ultrasonic sensor (13) that performs the position detection of the separating element (5) on the side of the media chamber (11) having the compressible fluid. A method for ultrasonic displacement measurement uses that system.

Abstract: A small volume prover apparatus and method for precisely measuring the displaced volume of a fluid. A precision bore cylinder and a piston can be configured with a valve arrangement in order to permit fluid to pass through an annular passage when the piston travels from one position to an opposite position. A magnetized forcer connected to the piston and a magnetic drive chamber configured to produce linear motion of said magnetized forcer are operably connected to the piston in order to move the piston from one position to the other.

Abstract: An apparatus having a transducer configured to generate acoustic energy, a buffer rod with a first end and a second end, the transducer in contact with the first end, a cylinder configured to define a volume, the second end of the buffer rod abutting the cylinder; and a piston within the cylinder.

Abstract: Apparatus for flow prover precisely measures the volume and the flow rate of a fluid through a cylinder. The prover includes a piston within a cylinder supporting a shaft extending longitudinally through the cylinder, which cylinder receives and discharges the fluid by translation of the piston from the fluid receiving end to the fluid discharging end. Motive means draws the shaft and piston toward the fluid receiving end of the cylinder. Travel of the piston in the direction from the fluid receiving end to the fluid discharging end of the cylinder is sensed at discrete locations to provide an indication of the volume of fluid therebetween and the related flow rate. Each of a plurality of emitter/detector modules provides piston position sensing signals reflective of the volume and rate of fluid flowing through the cylinder. A switch bar rigidly and permanently fixes the position of the emitter/detector modules with respect to the piston and with respect to one another.

Abstract: A master verification assembly includes a plurality of plunger devices. Each of the plunger devices includes a piston that is axially moveable between a raised position and a depressed position. When placed in a washing assembly, each of the plunger devices is aligned with a nozzle. The nozzles dispense a cleaning fluid under pressure. An axial force applied by the dispensed cleaning fluid depresses the pistons into the depressed position, whereupon the pistons disposed in the depressed position are axially secured in an indicator position. Upon removal of the master verification assembly from the washing assembly, depressed pistons in the indicator position indicate proper function of the nozzles, whereas pistons disposed in the raised position indicate improperly functioning nozzles.

Abstract: Disclosed is a bi-directional piston displacement type volumetric fluid flow rate delivery and metering system (calibration standard) and operational method for calibration of fluid flowmeters. The present invention provides reduced uncertainty of delivered volumetric fluid flow rate at meters under test relative to the uncertainty of volumetric fluid flow rate at meters under test provided by prior art bi-directional piston displacement type volumetric fluid flow rate standards given the same nominal cylinder diameters and working fluid and equal dimensional, timing and temperature measurement uncertainties by employing a plurality of metering pistons and cylinders to minimize the connecting volume piping between the metering piston cylinder outlet and meters under test, providing open access to one side of each metering piston to accomplish installation of temperature probes through the pistons into the working fluid and by operational method which minimizes the connecting volume to standard volume ratio.

Abstract: The present disclosure presents several embodiments for metering devices some of which also have pumping capability. The devices utilize one or more pistons located within a cylindrical rotor. As the cylindrical rotor is turned by a suitable torque/power source, a first face of each piston is exposed to an inlet supplying a fluid to be metered. The piston is then moved within the associated channel or bore within the rotor, allowing the volume of the channel to be filled with fluid. The continuing rotation of the rotor then removes the piston from the fluid supply and moves the channel through an angular displacement. The piston is then moved—either through applied power for active pistons or the force of the fluid supply for passive pistons—in the opposite direction, forcing the fluid out of the channel. In this way, a precise amount of fluid can be metered from each channel.