Abstract: An arrangement for measuring the true position of a diaphragm within a diaphragm valve assembly utilizes a thin conductive element disposed in the valve between the diaphragm membrane and the actuator. The conductive element and the valve body are then used as the plates of a parallel plate capacitor, where the measured capacitance will vary as a function of the position of the diaphragm mambrane, having a first value when the diaphragm is in the “open” position and a second value when the diaphragm is in the “closed” position. Position values between the “open” and “closed” positions can also be determined, as well as the presence of different fluids within the valve body when the valve is in the “open” position.

Abstract: An apparatus for testing hydraulic pressure relief valves has a fixture body with an internal cavity sized to receive the valve completely within the fixture body. A closure may be secured to the body to seal the valve within the cavity. The apparatus further includes inlet and outlet ports for providing a flow of high-pressure hydraulic fluid though the cavity, and a pressure port for coupling pressure monitoring instrumentation to the cavity. When a valve is installed within the apparatus and the inlet is coupled to a source of high-pressure hydraulic fluid, the actuation pressure of the valve may be determined by monitoring the instrumentation.

Abstract: A sump draining apparatus having an pressure transducer engaged in a receptacle that is in turn engaged in an open-ended collar of a housing. The receptacle and thus the pressure transducer is slideable in the axial direction into and out of the open-ended collar. The housing is generally cylindrical and contains a pump and motor, each of which has a generally cylindrical shape and is axially stacked in the housing. A cord having a vent and electrical leads for the pressure transducer is releasably engaged via a cord restraint at one end portion of the housing and the pressure transducer is releasably engaged in the receptacle in the open-ended collar at the other end of the housing. The receptacle and sensor may be removed, serviced, and/or replaced without the housing being opened and without the pump and motor being removed.

Abstract: A sensor component that may be used in conjunction with a filter module may include a plurality of sensor packages. The latter, in turn, may incorporate one or more micro-electromechanical systems (MEMS) sensors to measure various characteristics of fluid flow and filtration. A single sensor component may be adapted to measure the pressure, temperature, flow rate, differential pressure, conductivity, viscosity, pH level, etc. of the fluid at an upstream and a downstream location. Sensor measurements may be obtained continuously in order to monitor and indicate fluid conditions, including the use of a warning mechanism to indicate an out-of-range condition when the measurements fall outside of pre-set limits. Depending on the application and the fluid being filtered, data, including measurement data, may be transmitted through electrical connections or wirelessly. In wireless configurations, a sleep-mode may be included to maximize the life of local power supplies.

Abstract: A system and method for measuring fluid flow rate in a system where fluid is pumped, such as a gas monitoring instrument where gas is pumped from a space such as a room or enclosure through a conduit to a sensor. The flow of gas through a pump is determined by measuring motor back-e.m.f. which is proportional to motor speed. In a system where motor speed is regulated by pulse width modulation of the motor drive voltage, the back-e.m.f. is sampled during intervals between the drive pulses applied to the motor, and in a further aspect the sampling is done at selected, spaced-apart or infrequent intervals such as once for every ten or once for every hundred motor drive pulses. Advantageously, in an instrument that uses a microprocessor and analog-to-digital converter to measure gas-concentration, the same microprocessor and converter can provide the PWM control of the pump, in response to the back-e.m.f. generated by the pump motor between the drive pulses.

Abstract: A method and system for determining the actuating pressure of a servo cylinder that is actuated by pressurized fluid. The actuation displacement of the servo cylinder is obtained from a sensor or other device. A pressure sensor measures inflow pressure at one point of a pressurized fluid line supplying the servo cylinder. The actuating pressure is determined based on the inflow pressure and the change in the actuation displacement of the servo cylinder.

Abstract: A valve arrangement for use in a fire suppression sprinkler system includes a valve member for controlling the flow of a fluid. The valve member has a housing having an inlet and an outlet. The valve member defines a first configuration selectively permitting an unrestricted flow from the inlet to the outlet, and a second configuration selectively permitting a restricted flow from the inlet to the outlet. The valve member includes a first ball member and a second ball member disposed within the housing.

Abstract: The invention relates to a method for determining the current filling level of a liquid, preferably a calibrating, quality control, or cleaning fluid, or waste water, in a container, for example of an analyzer, where an immersion pipe is dipped into the liquid in the container to be filled or drained. The immersion pipe is connected to a pumping device via a tube system. The pressure p in the tube system is measured and increased, starting from the ambient pressure p0, until a first discontinuous pressure change occurs at pressure p1 due to the liquid column in the immersion pipe being forced out of the pipe, and/or the pressure p in the tube system is decreased until the liquid column in the immersion pipe reaches a change in cross-section of the immersion pipe, which change is situated above the maximum filling level of the liquid, such that a second discontinuous pressure change occurs at pressure p2 due to the liquid column reaching the change in cross-section.

Abstract: A method of determining flow through a valve includes determining a first differential pressure across the valve. The valve is bypassed and a second differential pressure is determined across the valve. A flow decision is determined for the valve based on comparison of the first and second differential pressures. A method of testing a relief valve in a reduced pressure backflow preventer assembly includes determining a first differential pressure across an upstream check valve during a no flow condition. The upstream check valve is bypassed for the purpose of opening a relief valve, and a zone vent is opened.

Abstract: A method for calibrating hydraulic actuators includes installing an actuator in a test stand and performing an electrical signal sweep to obtain a series of pressure values. Based on desired pressure values, signals yielding unwanted pressure values are removed and the remaining signal values and pressure values are stored in a central database as a look-up table for the actuator. Multiple actuators are then assembled to form a module assembly. The customized look-up tables for the actuators forming the module assembly are retrieved from the database. Based on those tables, signals are applied to the actuators to determine if the pressure values fall within specified tolerance windows. If the pressure values fall within the specified tolerance windows, the customized look-up tables are stored in the memory of a vehicle electronics package. If not, the signals are adjusted so that the pressure values fall within the specified windows, and the adjusted customized look-up tables are then stored in the memory.

Abstract: A method for determining whether a centrifugal pump is degraded as operating outside of acceptable operating limits and includes the steps of determining a motor torque/TDH relationship over a range of speeds for minimum and maximum flow rates and at least at two other intermediate flow rates, sensing and measuring at least another pump value selected from a differential pressure across the pump, a pump discharge pressure or pump flow, to provide an output pump value and comparing said value with said determined relationship values to provide an indication as to whether said pump has degraded.

Abstract: In the method for the determination of the pressure (p) in and/or of the through-flow (Q) of a liquid through a pump having at least one magnetic bearing for the axial journaling of the pump rotor (1), axial forces act on the rotor (1) of the pump during operation. The axial forces which act on the rotor are utilised for the determination of the pressure (p) and/or of the through-flow (Q).

Abstract: A method is provided for measuring a pressure of a hydraulic fluid that is supplied from a hydraulic fluid control device (1) to a operation device (6). The method includes measurement of a first pressure (Pm) and a second pressure (Pa). The first pressure is the pressure of the hydraulic fluid within a first flow path (P3 to P8) connecting a pressure control unit (3) and the operation device. The second pressure is the pressure of the hydraulic fluid within a second flow path (P11, P12) connecting an accumulator (22) and the pressure control unit. Then, a stabilization time (T) is determined. The stabilization time is the time when a pressure gradient per unit time of the second pressure become to be smaller than a predetermined value. Thereafter, a pressure (Pw) of the hydraulic fluid at the operation device is determined based on the first pressure that is measured at the stabilization time or at a time immediately after the stabilization time.

Abstract: A system for calibrating the fill times of clutches using a pressure transducer service tool includes attaching the tool to an electronic controller on the vehicle and the a clutch hydraulic fluid line, signaling the controller to calibrate the clutch, then removing the service tool. The tool is sequentially moved from one clutch hydraulic line to another to calibrate several clutches. A single service tool with several transducers and a means of switching between them may also be used. The process is automated and the controller signals the user when to make the various connections. The operator then signals the controller when the connections have been made and calibration commences automatically.

Abstract: The present invention is directed towards an apparatus for testing hydraulic components. The apparatus includes a test fixture for housing a hydraulic component to be tested, a first fluid reservoir containing fluid substantially free of contaminants, contaminant monitoring and pressure monitoring systems for monitoring the respective contaminants at, and the pressure drop across, the inlet and the outlet of the test fixture. The apparatus includes a plurality of second fluid reservoirs. Each second fluid reservoir can contain a slurry consisting of a known volume of fluid mixed with a charge of contaminants of known mass and can discharge this contaminant slurry into the inlet of the test fixture. Each second reservoir can be filled with fluid from the first fluid reservoir. One second reservoir can discharge its contaminant slurry into the inlet of the test fixture while one or more other second reservoirs receives fluid from the first reservoir.

Abstract: A method for monitoring the performance of internal pumps in a plant in which a coolant is driven through plural internal pumps, said method comprising measuring the pump motor power input to the motor driving said pump; estimating the power input to said pump motor during a test performed outside said plant corresponding to the pump speed and the pump flow measured within said plant; computing a pump motor input power ratio based on said measured value and said estimated value; and detecting the variation in the performance of said internal pumps.

Abstract: A system for calibrating the fill times of clutches using a pressure transducer service tool includes attaching the tool to an electronic controller on the vehicle and the a clutch hydraulic fluid line, signaling the controller to calibrate the clutch, then removing the service tool. The tool is sequentially moved from one clutch hydraulic line to another to calibrate several clutches. A single service tool with several transducers and a means of switching between them may also be used. The process is automated and the controller signals the user when to make the various connections. The operator then signals the controller when the connections have been made and calibration commences automatically.

Abstract: A self-contained system to continuously monitor a mechanism used to process, control or regulate fluid flow or pressure and provide a continuing indication of the status or condition of the monitored mechanism. A specific form of the invention employs a low frequency sonic-to-electrical transducer that monitors opening and closing of a disk-type steam trap. The detected sonic signal is processed and sent to a microprocessor that is programmed to develop a time-based, baseline data set representative of normal operation of the steam trap in the environment in which it operates. The baseline data set is compared with the data from on-line operations of the steam trap. As the environment and the steam trap operation change during normal on-line operations, the baseline data set is updated to change with the changing environment and the changing steam trap operation.

Abstract: A method for determining the suction pressure of a centrifugal pump including the steps of determining pump torque and pump discharge pressure at at least two different speeds, forming a first order wave curve as a straight line using said pump torque and pump discharge and determining suction pressure from the y axis intercept of said line.

Abstract: A centrifugal pump for transporting fluid with a housing, an impeller and a plurality of pressure sensors. Disposed within the housing is a volute section defined by a circumferential path through which a fluid may travel, a discharge section tangentially, aligned and in fluid communication with the volute section such that a flowpath is defined by fluid flowing from the volute section and through the discharge section; and a volute lip section defining a bifurcation point between the circumferential path and the discharge section. The plurality of pressure sensors are disposed within the volute section of the housing, and are spaced apart from one another such that pressure difference reading taken between each exhibit a substantially linear relationship with fluid flow rates to ensure accurate flow rate measurement.

Abstract: A diagnostic system for a valve (2) that can be actuated by a position controller via a drive. The diagnostic system includes a device (14) provided for recording, storing, and evaluating, body sound spectra on the valve. In order to enable a valve to be diagnosed in a particularly reliable manner, a body sound spectrum which is recorded when the intact valve (2) is slightly open is stored in the device (14) provided for recording, storing, and evaluating, whereby the valve can be closed for diagnostic purposes and the resemblance of the recorded body sound spectrum to the stored body sound spectrum is used as a criterion for evaluating a non-sealing condition of the valve.

Abstract: A retrofittable valve monitor provides an input to an electrical circuit to indicate a fully closed position of a ball valve. A magnetically permeable object attached to the ball valve lever handle actuates a magnetic reed switch in a proximity sensor when the ball valve is moved to the fully closed position. A bracket which fits between the ball valve body and the ball valve lever handle is held in place by the ball valve locking nut so the proximity sensor is held in proper alignment to be actuated by the magnetically permeable object. The actuated reed switch provides an input to a switched electrical circuit.

Abstract: A method and system for determining the actuating pressure of a servo cylinder that is actuated by pressurized fluid. The actuation displacement of the servo cylinder is obtained from a sensor or other device. A pressure sensor measures inflow pressure at one point of a pressurized fluid line supplying the servo cylinder. The actuating pressure is determined based on the inflow pressure and the change in the actuation displacement of the servo cylinder.

Abstract: A retrofittable valve monitor provides an input to an electrical circuit to indicate a fully closed position of a ball valve. A magnetically permeable object attached to the ball valve lever handle actuates a magnetic reed switch in a proximity sensor when the ball valve is moved to the fully closed position. A bracket which fits between the ball valve body and the ball valve lever handle is held in place by the ball valve locking nut so the proximity sensor is held in proper alignment to be actuated by the magnetically permeable object. The actuated reed switch provides an input to a switched electrical circuit.

Abstract: A system for measuring the distance of a hydraulic movement including an engine supplying power, a hydraulic cylinder for supplying hydraulic movement, and a pump coupled to the hydraulic cylinder for providing hydraulic fluid to the hydraulic cylinder. A power take off is coupled to the engine and supplies power from the engine to the pump. A measuring device measures the amount of fluid provide to the hydraulic cylinder by counting engine revolutions enabling a determination of the distance of the movement.

Abstract: A method for checking the operational readiness of a valve determines at least one measured value for a valve-specific parameter and compares it with a previously fixed value. The measured value is determined in a cold and unpressurized state of the valve and is compared with a value that is determined analytically from a function model of the valve, for the valve-specific parameter. An upper and a lower limiting value which are fixed for this analytically determined value are assigned to states of the valve that are still tolerable (design reserve). It is indicated that the valve is operationally ready when the measured value is between the upper and the lower limiting value.

Abstract: A combined alarm test and drain device for a fire protection sprinkler system is disclosed. The apparatus is based on a globe valve and has certain specific modifications for the purposes of draining the system and allowing for flow through a specifically sized orifice under conditions simulating the flow through a sprinkler head having the same orifice size. Fluid flow through the apparatus occurs alternatively under a first set of conditions in a system alarm test mode of operation of the apparatus, and under a second set of conditions in a system fluid drainage mode of operation of the apparatus. A combination of mechanical and hydraulic forces are utilized to control opening and closing of the valve in both the alarm test and system fluid drainage modes of operation. The mechanical force is provided by a spring and the hydraulic force is provided by a fluid pressure differential.

Abstract: A method and system for determining pump cavitation is disclosed. In accordance with the principle of the invention, changes in dynamic fluid pressure within a pump are monitored and compared to a determined cavitation alarm pressure. The determined cavitation pressure is determined as a known percentage of a known non-cavitation pressure. Fluid cavitation is determined when the change in dynamic fluid pressure falls below the determined cavitation alarm pressure. In a further aspect of the invention, a remaining mechanical seal operational life can be determined by maintaining a total time of fluid cavitation and reducing the expected life by the known operational time of the pump and the time the pump is in cavitation.

Abstract: Piezoelectric transducer assemblies that are useful for the monitoring of the gas output from a gas driven pump, wherein the assembly is not an integral part of the input or output flow stream of the material being pumped, but is used to monitor the exhaust gas flow of the gas driven pump.

Abstract: A method for monitoring the performance of internal pumps in a plant in which a coolant is driven through plural internal pumps, said method comprising measuring the pump motor power input to the motor driving said pump; estimating the power input to said pump motor during a test performed outside said plant corresponding to the pump speed and the pump flow measured within said plant; computing a pump motor input power ratio based on said measured value and said estimated value; and detecting the variation in the performance of said internal pumps.

Abstract: A rotating plug (4) is installed in a body (1) and can be in different positions in which two lateral drillings come in front of the orifices corresponding to the body (1) or a sampling orifice (18) in front of which a flask is placed. The fluid to be sampled is circulated so that it fills a chamber (12) delimited by the rotating plug (4), and the rotating plug is then turned until one of its drillings is facing the sampling orifice (18) and a piston (11) delimiting the chamber (12) is pushed in to extract the required quantity of the sample. This device is simple and has an excellent seal.

Abstract: A method and system for determining pump cavitation is disclosed. In accordance with the principle of the invention, changes in dynamic fluid pressure within a pump are monitored and compared to a determined cavitation alarm pressure. The determined cavitation pressure is determined as a known percentage of a known non-cavitation pressure. Fluid cavitation is determined when the change in dynamic fluid pressure falls below the determined cavitation alarm pressure. In a further aspect of the invention, a remaining mechanical seal operational life can be determined by maintaining a total time of fluid cavitation and reducing the expected life by the known operational time of the pump and the time the pump is in cavitation.

Abstract: The present invention provides a method and apparatus for detecting a status of a valve, the valve being connected to a fluid circuit. The method includes the steps of establishing an expected value of a characteristic of the fluid of the fluid circuit, determining an actual value of the fluid characteristic of the fluid circuit, and determining a valve status in response to the actual value, and the expected value.

Abstract: A method and apparatus statistically determines estimates of one or more process control loop parameters, such as bearing friction, seal friction, total friction, dead band, dead time, oscillation, shaft windup or backlash associated with a device or a control loop within a process control environment. The method and apparatus measures one or more signals within a process control loop when the process control loop is connected on-line within a process control environment, stores the measured signal as signal data and then performs one of a number of statistical analyses on the stored signal data to determine the desired parameter estimate.

Abstract: Improved methods and systems are provided for detecting surge bleed valve faults and analyzing the performance of surge bleed valves in gas turbines. The method includes monitoring the rates of rotation of an engine fan and an engine gas generator in a gas turbine engine. While so doing, a valve status change signal is transmitted to a surge bleed valve in the gas turbine engine. The difference between the two monitored rates of rotation is determined. A surge bleed valve fault signal is generated if the difference between the two monitored rates of rotation does not change by at least a predetermined amount immediately following transmission of the valve status change signal to the surge bleed valve.

Abstract: A method and apparatus for determining the efficiency of a liquid pump using air as a test medium. The method includes determining the total power output of the pump operated on air and determining the input power necessary to operate the pump on air. The input power is corrected for power differences resulting from operation of the pump on air rather than a liquid to obtain a corrected power input. The corrected power input is then divided into the power output to determine pump efficiency. The apparatus for performing the method includes a liquid pump arrangement temporarily connected to a bearing arrangement. The bearing arrangement is designed to support only the static load of the pump and the dynamic loads generated by operating the pump on air. This allows a bearing housing to be used that is smaller in size and less expensive to use. In addition, because the pump is operated on air, the components for feeding the air are less expensive as is the medium itself.

Abstract: An apparatus for testing the ability of a filter to filter contaminants, by automatically controlling and/or monitoring various parameters, including the following, among others: the flow of fluid through a test filter; the rate of injection of contaminants upstream of the test filter; the variation in the flow of fluid through the test filter; contaminant particle count upstream and downstream of the test filter; vibration of the test filter; temperature of the fluid flowing through the test filter; and the pressure drop across the test filter.

Abstract: A hydraulic cylinder monitoring apparatus of a type having a tube with a first end and a second end and a removable first cap member for selectively closing the first end of the tube, the first cap member having a first opening therein. A second cap member is welded to the other end of said tube, the second cap having a second opening therein. A piston is sealingly disposed within the tube for movement between a first and a second position between the first and second ends of the tube. A rod is operatively attached to the piston and extends from the piston and through the first opening in the first cap member whereby the piston and rod can move together between the first and second positions. A first hydraulic fluid port extends into the tube adjacent said one end of the tube. A second hydraulic fluid port extends into the tube adjacent the second end of the tube. A supplemental cap is removably attached to the second cap member, the supplemental cap having a passageway therein.

Abstract: A method and an arrangement for testing valve disks of ceramic charge cycle valves for internal-combustion engines is provided. Two stressing rollers are pressed against a radially outer section of a valve seat side of the valve and a third stressing roller is provided against the other side of the valve intermediate the other two stressing rollers.

Abstract: A partial stroke testing system for online testing of emergency shut-off valve, said system is designed for implementation on an emergency shut-off valve with a main solenoid with manual reset, main solenoid valve, quick exhaust valve and a pneumatic actuator connected to a source of pressurized air supply for opening and closing the said emergency shut-off valve and the said shut-off valve normally movable between a fully open and fully closed position. The system also include control means programmed into the plant emergency shutdown system controller for initiating electrical signal for initiating a test and for enhancing the bleed rate from the said pneumatic actuator in the event of a emergency trip signal. Test means for testing the said emergency shut-off valve without fully closing the emergency shut-off valve in response to signal from the said control means is included in the system.

Abstract: A partial stroke testing system for online testing of emergency shut-off valve, said system is designed for implementation on an emergency shut-off valve with a main solenoid with manual reset, main solenoid valve, quick exhaust valve and a pneumatic actuator connected to a source of pressurized air supply for opening and closing the said emergency shut-off valve and the said shut-off valve normally movable between a fully open and fully closed position. The system also include control means programmed into the plant emergency shutdown system controller for initiating electrical signal for initiating a test and for enhancing the bleed rate from the said pneumatic actuator in the event of a emergency trip signal. Test means for testing the said emergency shut-off valve without fully closing the emergency shut-off valve in response to signal from the said control means is included in the system.

Abstract: A sign of abnormality of a valve apparatus during its operation is grasped, an abnormal position and a portion requiring repair are specified, a range of inspection of an electric valve is limited and the degree of the sign of abnormality is judged without touching at all the valve apparatus. A driving force sensor provided to a driving portion of a valve apparatus is connected to a diagnosing apparatus, an energy sensor for detecting feed energy to the driving portion and a vibration sensor for detecting vibration of the valve apparatus are provisionally fitted to the valve apparatus. A data conversion unit converts the detection signals outputted from these three kinds of sensors to predetermined signals.

Abstract: A drug pump testing system and method comprise a pump control module having tube engaging members, with the pump control module coupled to a calibration cassette. The calibration cassette houses a reservoir bag comprising a fluid chamber and a collection area. The fluid chamber contains a known test volume prior to the initiation of the test cycle. The fluid chamber of the reservoir bag is coupled with a tube leading to the collection area, and the tube is positioned along the calibration cassette for occlusion by the tube engaging members of the pump control module. The reservoir bag comprises a fluid chamber and a collection area. The cassette can be a dual purpose cassette which tests sensors on the pump control module and also tests the accuracy of the pump control module.

Abstract: A position sensor and a method for sensing a position of a moveable member includes at least first and second deflectable members arranged so as to allow the moveable member to pass therebetween and cause the at least first and second moveable members to deflect in proportion to the position of the moveable member relative to the first and second deflectable members. In one example of the present invention, the deflectable members are cantilever-mounted members extending in generally the same direction. The amount of resultant deflection is measured by any suitable means. For example, each deflectable member may have a Wheatstone bridge provided thereon acting as a strain gauge in a known manner, such that the strain detected is proportional to the amount of deflection. In a particular example of the present invention, some of the elements of a first Wheatstone bridge are provided on the first deflectable member and some are provided on the second deflectable member.

Abstract: Operation of an electrically operated valve is calibrated by applying a gradually increasing electric current to the valve. While that is occurring pressure at either the inlet or outlet of the valve is measured to detect when the valve opens. When the valve opens the level of the electric current then being applied to the valve is employed to determine an initial current level to use subsequently whenever the valve is to be opened.

Abstract: A compressor for processing a compressor gas is provided. A performance map is provided that comprises a plurality of performance curves showing head and flow conditions at various compressor speeds. The performance curves terminate at one end at surge points. Also provided is a processing and calculating unit interfaced with the compressor, for measuring performance parameters of the compressor necessary to determine actual head and flow conditions of the compressor at a given processor speed and for performing calculations. The compressor map performance curves are converted into deviation curves, where the deviation curves represent deviations from the surge point at the head and flow conditions. The deviation curves are merged into a universal compressor curve with a merge-function to within a pre-defined tolerance. Imaginary map head and flow values are calculated using the universal compressor curve, merge-function, deviation curves, and performance curves at the compressor speed.

Abstract: The present invention aims to permit an easy and reliable predicting of abnormality of a solenoid valve before failure, by detecting operating times of the solenoid valve and discriminating, from the operating times, whether the changeover operation thereof is normal or abnormal.

Abstract: Systems and methods are discussed that monitor wear in seat materials of a valve. One aspect of the present invention includes a system. The system includes sensors to sense the open/closed status of the valve within a desired range. The system also includes a set of counters to count each time the desired range is adjusted to characterize the valve as having the open/closed status if the valve was not within the desired range. The count of each counter is indicative of wear in seat materials of the valve. Another aspect of the present invention includes a method. The method includes determining an open/closed status of the valve within a desired range, and adjusting adaptively the desired range so as to characterize the valve as having the open/closed status if the valve was not within the desired range. Each iteration of adjusting is indicative of wear in seat materials of the valve.

Abstract: A sensor for detecting contact of a fluid delivery probe with a fluid surface and for detecting fluid flow through the probe includes a first electrode disposed along a fluid flow path of the probe upstream from a distal tip of the probe and a second electrode longitudinally spaced and electrically isolated from the first electrode and disposed at the distal tip of the probe. An oscillating signal is transmitted through the first electrode, and at least a portion of the signal is received through the second electrode. Through changes in the received signal due to the distal tip of the probe coming into contact with a fluid surface or due to fluid flow through the conduit between the first and second electrodes, fluid surface contact and fluid flow can be detected. A pressure sensor can be employed to monitor internal fluid pressure within the fluid conduit of the fluid delivery probe as a secondary, redundant means for detecting fluid flow through the conduit.

Abstract: A test device and a process for determining the accuracy of positive displacement gear pumps includes hydraulic cylinders which are fluidly connected to the output fluid flow(s) from a test pump. Each outlet flow is directed to a separate hydraulic cylinder. The test pump is driven by a motor for a preset number of revolutions. The length of stroke of the piston in each hydraulic cylinder is then determined, which corresponds to the volume of fluid provided from each pump outlet during the revolution of the gears in the pump. It can then be determined if the volumetric accuracy and efficiency of the pump is within acceptable limits.