Abstract: A positive verification of fluid flow from a reservoir through a metering pump is provided by monitoring the downstream fluid pressure fluctuations caused in the fluid conduit by inserting a pressure sustaining valve in it. A pressure switch or similar device coacts with a pulse timer to monitor the periodic pressure fluctuations in the conduit. A lapse in the periodic pressure fluctuations for a specified time allows the timer to activate an alarm signal.

Abstract: A particle analyzing apparatus having sample liquid pressurizing means for pressurizing sample liquid containing therein particles to be examined and supplying it to a portion to be examined, sheath liquid pressurizing means for pressurizing sheath liquid and supplying it to the portion to be examined in such a manner as to surround the sample liquid, a pressure sensor provided in the flow path of the sheath liquid between the sheath liquid pressurizing means and the portion to be examined, pressure control means for controlling the pressure value of the sheath liquid pressurizing means so that the output of the pressure sensor becomes constant, and means for applying light to the portion to be examined and photometering light emitted from the particles to be examined to thereby effect particle analysis.

Abstract: A detection system is provided for sensing a malfunction of a valve having an outlet connected to an end of a first pipe through which pressurized fluid may be flowed in a downstream direction away from the valve. The system includes a bypass pipe connected at its opposite ends to the first pipe and operative to bypass a portion of the fluid flow therethrough around a predetermined section thereof. A housing is interiorly divided by a flexible diaphragm into first and second opposite chambers which are respectively communicated with the first pipe section and the bypass pipe, the diaphragm being spring-biased toward the second chamber. The diaphragm housing cooperates with check valves and orifices connected in the two pipes to create and maintain a negative pressure in the first pipe section in response to closure of the valve during pressurized flow through the first pipe. A pressure switch senses the negative pressure and transmits a signal indicative thereof to a computer.

Abstract: A vacuum-attraction holding device includes a holding base having an attracting surface, for holding a substrate thereon; a suction passageway formed in the base, for supplying a vacuum to the holding base to attract the substrate to the attracting surface; and a pressure sensor provided in the base and being communicated with the suction passageway.

Abstract: A fluid flow rate responsive signal generator includes moveable members which, in part, define a pair of paths for the flow of fluid. A first of the moveable members is a shuttle which supports a magnetic field generator, the shuttle being displaced toward a proximity switch in response to fluid flow. The second moveable member functions as a valve which, when in the open condition, allows flow to bypass the flow path in which the shuttle is disposed. The bypass flow path control valve member will be automatically positioned as a function of the dynamic flow conditions and may be either normally closed or prepositioned to define a minimum bypass flow path area.

Abstract: An ultra low pressure flow sensor consisting of a support gasket defining a flow way and having a thin, pliable membrane extending thereacross with right angle slits formed totally across the flow way portion. An electrical conductor strip is then bonded across each pair of opposing quadrants of the membrane in continuous connection to an electrical indicator circuit. The conductor strip across each pair of membranes is centrally notched to a preselected depth of cut thereby to adjust the flow pressure break strength.

Abstract: A fluid flow sensor for use with a fluid circulating system to indicate a predetermined rate of fluid flow therethrough, fluid flow sensor comprises a hollow fluid flow sensor body including a lower flow detection chamber and an upper fluid flow chamber formed therein and a float movable between a lower and upper position disposed within the hollow fluid flow sensor body, a float position sensing device including logic circuitry to selectively generate a first and second signal disposed adjacent the lower portion of the lower flow detection chamber and a float limit disposed within the upper fluid flow chamber, the float being disposed adjacent the float position sensing device when in the first position when fluid flow through the fluid flow sensor is less than the predetermined rate of fluid flow whereby the float position sensing device generates the first signal to indicate fluid flow of less than the predetermined rate and when the fluid flow through the fluid flow sensor equals or exceeds the predetermi

Abstract: The present invention is related to the fluid flow sensing and switching device installed in an air-conditioning system, particularly in a heat exchanger, which has a hollow body or housing to accommodate a metallic sensing member with a pair of conductive terminals extending out thereof, while it is further sealed by resin. A ring member is slidably mounted with a pair of legs extending downwardly from the hollow body, which is positioned facing the fluid flow, so as to activate the metallic sensing means and further to control a compressor connected with the system.

Abstract: An apparatus and method for detecting pressure and occlusion in a fluid line is for use with a fluid line being operated upon by a positive displacement, peristaltic pump having several cam follower fingers pressing against the fluid line fluid through the line peristaltically. A sensor follower finger is mounted to the cam shaft of the pump among the other peristaltic fingers in order to cyclicly press against the fluid line and displace the fluid line by a predetermined amount as the cam shaft rotates. The sensor follower finger includes a strain gauge mounted on the sensor finger to generate a signal indicating the degree of force being applied by the sensor finger against the tubing, and a signal processor which receives this force signal and determines the pressure within the fluid line based upon the signal. The signal processor determines the existence of an occlusion based on the signal and provides an alarm if an occlusion is determined.

Abstract: An oil filter for filtering oil is combined with a differential pressure indicator with temperature compensation. The differential pressure indicator has a spool assembly slidably disposed in a spool insertion cylinder in axially confronting relation to a terminal which is connected through a warning lamp to a battery. The spool assembly comprises a spool body disposed for axial sliding movement in the spool insertion cylinder, a contact member disposed for axial sliding movement in the spool body and having a contact pin movable out of one of the spool body, and a spring of a shape-memory alloy, restorable to a memorized shape when the oil is in a predetermined temperature range, for biasing the contact member to move the contact pin out of the spool body towards the terminal. When a differential pressure in excess of a predetermined level is developed in the oil and applied to the spool assembly, the differential pressure acts to move the spool assembly towards the terminal.

Abstract: A medical gas alarm system is provided which includes a sensor unit pneumatically connected to a medical gas supply line and a switch connected to a valve in the supply line for detecting the open condition of the valve. In the event either the sensor detects a high pressure or low pressure condition in the supply line or the switch is activated by closing of the valve, an alarm signal is received by an alarm module and an alarm is activated. The alarm may be visual, audible or both. During normal operations, the alarm module displays both a system on condition and a digital display indicating the pressure in the supply line.

Abstract: A flow sensor for detecting the absence of a minimum fluid flow in a sprinkler system. The fluid acts upon a vane positioned in the fluid path. Movement of the vane controls the position of a slider. The slider's surface has reflective and non-reflective ends which, in response to the vane's movement, reflect or absorb light from a light emission and detection means. The voltages from the light emission and detection means are monitored for indications of the fluid flow. The sensor uses a two wire signal transmitting system.

Abstract: Control system for measuring/detecting transient fluid flow in a positive displacement pump lubrication system using time-differential pressure measurements. A pressure-actuated transducer for a captive oil column in the injection circuit imparts a proportional voltage signal to an electronically differentiating high pass filter, rendering it independent of any base line steady-state component. The resultant signal is fed into a comparator used to discriminate rates of pressure change against a preset reference level, thereby sensing transient spike pressures covering a wide range of adjustable frequencies and pump displacement strokes to thereby confirm required lubrication flow. The same transducer voltage signal transmitted during a steady-state portion of the pump cycle between injections is monitored for high and low set points such as incident to downstream blockage or system leakage.

Abstract: A restricted flow alert for use in the access arm of the main clean-out plug location in a commercial or residential sewage system includes a diaphragm which moves in response to the presence of to close a switch and actuate an alarm. A pneumatic time delay prevents the alarm from being actuated in response to transient flow conditions in the sewer line and allows operation of the alarm at any physical orientation relative to the axis of the body of the restricted flow alert.

Abstract: A method and apparatus to evaluate the performance of an implanted medication delivery device such as pumps and ports is described. In the case of a pump, the system measures ambient pressure and obtains two pressure measurements from the implanted device. One of these measurements is device reservoir pressure and the other is based on a disturbance pulse injected into the system at a point downstream of the reservoir. Based on those measurements and input calibration data, an expected flow rate is determined. The expected flow rate together with device refill data is in turn used to determine a normalized flow rate for the in-vivo device. Determinations are then made as to the performance of the reservoir, its pump and the condition of the outlet catheter without explant of the device. In the case of a port, the system measures the catheter resistance based on decay time of a disturbance pulse.

Abstract: The invention is an electronic monitor for monitoring the pressure of in fluid circuitry and governing the shutdown in such mechanisms as dynamometers. The monitor has two pressure switches at every point in the fluid circuitry where pressure is sampled, and has a monitor circuit responding to signals from the switches to selectively energize lights indicating the status of the fluid circuitry. The monitor has a circuit for shutting down the dynamometers and other equipment when pressure falls below a predetermined threshold at one of the pressure monitoring points. The monitor also has a circuit for detecting which of the points is first to experience a fall in pressure below the threshold when the fluid circuitry as a whole is losing pressure.

Abstract: A rupturable fluid flow indicator and a rupture disk assembly including the indicator are provided. The indicator is comprised of a rupturable member adapted to be clamped across a fluid flow passageway having at least one opening formed therein for weakening a portion of the member. An electric current conductor adapted to be electrically connected in an alarm circuit is attached across the weakened portion of the rupturable member whereby when the member ruptures as a result of fluid pressure exerted thereon, the conductor also ruptures.

Abstract: In a particle counting system for sensing and counting particles, a sample fluid is drawn through an orifice from a sample chamber into a substantially enclosed fluid passage at a selected rate sufficient to maintain the pressure in the substantially closed fluid passage at a predetermined pressure level if the orifice and the substantially closed fluid passage are free from leaks and clogs. A sensor detects the actual pressure in the substantially closed fluid passage. The actual pressure is compared to the predetermined pressure level to identify clogs or leaks in the particle counting system. If a clog is identified, an automatic clog removal sequence is inititiated for dislodging or otherwise removing the clog from the particle counting system. The particle counting system is tested to determine if the clog has indeed been removed.

Abstract: An apparatus for determining the rate of discharge from a nozzle for spraying an aqueous solution of hydrogen peroxide comprises a pressure sensor for detecting the internal pressure of a pipe for supplying the solution to the nozzle under elevated pressure, and means for determining the rate of discharge from the pressure detected by the pressure sensor and the predetermined relationship of the discharge rate of the nozzle with the internal pressure of the pipe.

Abstract: A flow sensor for detecting the absence of a minimum fluid flow in a sprinkler system. The fluid acts upon a vane positioned in the fluid path. Movement of the vane controls the position of a slider. The slider's surface has reflective and nonreflective ends which, in response to the vane's movement reflect or absorb light from a light emission and detection means. The voltages from the light emission and detection means are monitored for indications of the fluid flow. The sensor uses a two wire signal transmitting system.

Abstract: A device and system for detecting the existance of fluid flow from a fluid source to a pipeline includes a cylinder with an inlet at a first end and a lateral outlet. A piston in the cylinder is moveable from a no-flow position abutting the first end in which it is maintained by a spring, to a flow position in which the piston at least partly opens the lateral outlet, by fluid flowing from the inlet to the lateral outlet. A magnetic switch detects the no-flow position of the piston, and actuates a radio transmitter to send a no-flow condition alarm. The device is used to detect interruptions in the supply of additives to oil and gas pipelines.

Abstract: The invention discloses a method and an apparatus for explosion protection of plants, pipelines and the like by monitoring chronologically successive values of the system pressure in the potentially explosive area and by comparing these values with a predetermined pressure threshold, where the exceeding of this pressure threshold is used as a triggering criterion for initiating explosion protection provisions. According to the invention, instead of predetermining a constant value as the pressure threshold, the pressure threshold is updated continuously in accordance with the system pressure prevailing at that time. As a result, the pressure threshold can be set with a smaller safety margin above the system pressure than before. Brightness and temperature thresholds may also be used singly, or together with pressure in any combination in continuous value monitoring.

Abstract: A method and solid-state electronic flowmeter with no moving parts is provided for monitoring instantaneous and/or accumulated fluid flow. A preferred application for the method and flowmeter is the measurement of the total volume of filtered fluid in a fluid treatment system as an indication of end of life for a filter therein. The flowmeter employs a solid-state transducer which senses differential pressure generated by a flow restriction such as a venturi which varies depending on a rate of flow. The transducer output in integrated over time to provide a representation of total fluid flow through the filter. The meter is preferably compact and battery-powered to facilitate ease of installation and use. Battery power is conserved by periodically energizing the transducer during idle periods and by periodically energizing the end of life indicator during and end of life condition.

Abstract: A system and method for alerting a crew member if his anti-G system is not at the proper pressure during a flight. Flight condition sensors and an anti-G suit pressure sensor input data to a computer controller. The controller selects a pressure for protecting the crew member against blackout based on the input and data stored. The controller generates a signal to change the pressure in the anti-G suit to the selected pressure. The controller monitors the pressure status of the anti-G suit and rate of pressure change over time after the signal is generated. If the anti-G suit does not reach the selected pressure within a selected time, an alarm is provided to the crew member. Early warning, caution or failure alarms are generated if the suit does begin to inflate immediately or if it fails to reach a threshold pressure after a threshold time.

Abstract: An air sampling and alarm control system for detecting the presence of a toxic contaminant in the atmosphere and for providing an audible alarm when insufficient gas flow is present in the system to adequately test for the presence of the contaminant. The alarm control is provided by a pressure switch which is electrically connected in circuit with an audible alarm and pneumatically connected in circuit with the gas flow line connecting the sampling pump to the sampling detector.

Abstract: The apparatus is of the kind comprising a flow detector supplying, in the absence of flow, a stop down signal for the pump, a pressure detector supplying, for a predetermined minimum value of the pressure, a start up signal for the pump, and impeller means for the pressure detector, and is featured by the fact that the pressure detector comprises a movable part (1, 2) which is integral with a membrane (3) closing a cavity (3b) communicating with the hydraulic network, and a fixed part (4, 5) arranged in the apparatus body at the displacement position of the movable part (1, 2), the impeller means for the movable part of the pressure detector are constituted of a spring (8) mounted between the said movable part (1, 2) and the apparatus body (9), the flow detector comprising a part (6, 7) which is movable in the vertical direction and performs the function of gravity closing valve, and a fixed part (4, 5) which is arranged in the apparatus body.

Abstract: The ratio of the pressure change across a portion of the ventilation system of a hydrogen cooled electric power generator to the pressure increase across a reference blower, preferably the purity blower, is compared to a base ratio to generate an alarm when the difference in ratios exceeds a predetermined amount indicative of a failure within the ventilation system.

Abstract: Monitoring a room is accomplished by measurement of air pressure where air passage resistance between a secured room and an outside atmosphere is measured and an alarm actuated, if the air passage resistance drops below a predetermined value. Evaluation of typical air pressure fluctuations in a frequency range between 0.01 Hz and 10 Hz is advantageous. The air pressure resistance may be determined by difference measurements of air pressure fluctuations in the outside atmosphere and the secured room, or as a singular process wherein a connecting tube is provided between the room to be secured and the outside atmosphere, where air movements varying as a function of air pressure fluctuations are measured. Devices for the carrying out of the process are described. The devices and the process provide a simple and cost effective alarm system that operates reliably and is secure against outwitting and sabotage.

Abstract: A gas flow indicator comprises a housing defining a cylindrical flow passage having axially spaced first and second ends. A cylindrical piston member having first and second terminal ends and an exterior diameter which is substantially less than the diameter of the passage is axially positioned in the passage with its first terminal end facing the first end of the passage. The piston is mounted for sliding movement from a first position adjacent the first end of the passage to a second position adjacent the second end of the passage when gas flow through the passage exceeds a predetermined level. A flow passageway extends through the piston member from an inlet adjacent the first terminal end to a flow control outlet orifice spaced axially from the first terminal end.

Abstract: A pressure-biased, temperature sensor means utilizing a cooperating pair of aligned bellows operators in a chamber communicating with a fluid to a reference pressure. One of the bellows is responsive to an elevated temperature of a fluid coolant system and the second bellows, which communicates with the fluid coolant system, is responsive to a decrease in fluid pressure. The aligned bellows cooperate to move a switch actuation means to close a switch thereby completing a signal circuit and energizing a signal means.

Abstract: An excessive gas flow detector has a probe in which an electrode and immediately surrounding part of an insulating sleeve are protected by a shielding ring surrounding the electrode from direct impingement of spray carried by gas sweeping down into a well under excessive gas flow conditions. A test unit for plugging into a socket of the detector gives an indication on light emitting diodes of whether there is an excessive or normal gas flow through the detector.

Abstract: A pressure-biased, temperature sensor means utilizing a cooperating pair of aligned bellows operators in a chamber communicating with a fluid system. One of the bellows expanding in response to an elevated temperature of said fluid and the second bellows expanding in response to a decrease in fluid pressure. Both of the bellows operate to move a diaphragm operator to close a switch means in a signal circuit thereby completing the circuit and energizing a signal means.

Abstract: By providing a pressure responsive actuator in controlled actuating engagement with a latch mechanism in which a spring-loaded indicator is securely retained, with said indicator being movable from a non-visible, retained position to a visible, released position in response to pressure exceeding a desired level, a unique, precision constructed pressure sensor and indicator is achieved. In the preferred embodiment, the latch mechanism comprises a plurality of elongated, resilient, spring-biased locking fingers, with the locking fingers being controllably disengaged from the indicator in response to the movement of the pressure responsive actuator. In addition, the present invention is also quickly and easily manually reset, thereby further enhancing the usability of the present invention.

Abstract: An element placed within a cotton conveying duct of a cotton harvester above the air discharge jet is shaped to shed cotton and supports a vacuum opening which communicates with a simple differential pressure switch through a vacuum conduit. The aspiration effect of normal air flow over the opening provides a vacuum in the conduit which maintains the switch open, but if air velocity in the duct drops below a preselected value due to a plug, low fan speed or faulty hose, the vacuum decreases and the switch closes to energize a warning device.

Abstract: A pressure-temperature sensor for monitoring a fluid system for an over-temperature, an under-pressure or an over-pressure condition. The sensor includes a bellows operator enclosed in a fluid-filled housing with a normally-closed, first switch means and a normally-open second switch means. A diaphragm operator and a bellows are responsive to changes in temperature and pressure to, respectively, operate the first and second switches to indicate an over-temperature, an under-pressure or an over-pressure condition.

Abstract: A pressure-biased, temperature sensor for monitoring a fluid system for either an over-temperature or under-pressure condition. The sensor includes a bellows operator immersed in the fluid of a coolant system. The bellows operator expands in response to changes above a predetermined temperature or below a predetermined pressure to complete a signal circuit and energize a signal means.

Abstract: This device periodically isolates a sample of a beverage in production and determines the level of Carbon Dioxide present in the sample by the pressure temperature method. This system eliminates the overpressure in the line and then computes the carbonation level in the beverage to the same precision as standard laboratory instruments. The line pressure is often higher than the equilibrium pressure in the finished container by a significant factor (1.5 to 2) and is also fluctuating. By properly equilibriating the sample before testing these problems are eliminated.

Abstract: IA purge block is disclosed in which inlet, process, purge and vent ports are series connected in a ring or bridge. The channel or passageway connecting the inlet and purge ports comprises a flow sensor. The impedance to gas flow of each channel is different from the others. The impedances are chosen such that improper operating conditions cause an imbalance in the flow which is detected by the flow sensor. During normal operation of the system in which the purge block is used, the flow sensor acts as an excess flow detector by comparing the flow through itself with the flow through a parallel, but more restrictive, path within the purge block.

Abstract: In combination with a blood reservoir, a blood volume detecting apparatus is used to ensure safe operation of the reservoir which includes a conduit in fluid communication with a lower part of said blood reservoir, a diaphragm associated with the other end of the conduit and movable by a differential hydraulic pressure applied by the blood through the conduit, and means for detecting the swelling and contracting movement of the diaphragm.

Abstract: A safety device for the conductive-fluid circulation system of an ink-jet printer consists of a sensor and an associated electronic circuit inserted between an ink-drop recovery trough and a recirculating pump. The level of turbulence of the fluid flow within a pipe segment of insulating material located between two conductive pipe segments is determined by the sensor by measuring the variation in conductivity in relation to variations in cross-sectional area of fluid within the insulating pipe segment and by delivering a control logic signal.

Abstract: A sewer line backup detection device and alarm are provided which can be installed in place of the cleanout access cap in a conventional sewer line. The device comprises a housing having male connecting threads adapted to fit standard female receptacles which have been used in the past to provide cleanout access to sewer lines, the housing containing alarm means or alarm transmitting means actuated by a pneumatic switch. The pneumatic switch is actuated by a flexible diaphragm which is fitted snugly onto the lower end of the housing which extends into the sewer line. In the event of a blockage of the sewer line, the blocked material exerts pressure on the flexible diaphragm which closes the pneumatic switch thereby setting off an alarm, either locally or at a remote location such as the dwelling from which the sewer line exhausts. The alarm system is utilized especially advantageously in combination with a detention tank located in the basement or lower level of a high rise building.

Abstract: A warning means for a safety valve of a hydraulic power unit and a hydraulic power unit having the same for use in a lifting jack, a vehicle lift, or the like, are disclosed. When an overload is given to a cylinder chamber of a hydraulic power unit, a safety valve is automatically opened so as to release an oil in the overloaded cylinder chamber back to an oil tank. When the safety valve is opened, a warning means switches on a caution buzzer and a caution lamp to appeal the overload to the senses of eyesight and hearing of a human being in order to prevent an accident to be followed previously. The warning means comprises a reed switch and a magnet adapted to be moved by the oil passed through the safety valve.

Abstract: Inhalation therapy apparatus comprises a mouthpiece through which air is to be inhaled and provides a pneumatic signal related to the volume of air inhaled. The pneumatic signal is transduced to electrical information and provides visual indicia to be observed by the patient to encourage the patient's performance. One row of lights indicates a desired level of inhalation to be attained, while a parallel row of lights indicates the inhalation actually attained. A step wise visual configuration also is provided encouraging the patient to increase his inhalation step by step. A visual display is also provided of the total number of attempts or inhalations, and also the number of times that the desired volume is attained.

Abstract: An engine oil pressure monitor includes an engine oil pressure sensor and an engine speed sensor. A plurality of pressure alarm values are generated to correspond to designated distinct ranges of engine speed. One of the alarm values is selected according to which engine speed range contains the sensed engine speed. An alarm signal is generated when the sensed pressure falls below the alarm value. The alarm is disabled when the engine speed falls below a minimum non-zero engine speed and is disabled unless the pressure failure condition persists for at least a predetermined time period.

Abstract: A vehicle, such as an agricultural tractor, includes a hydraulic assist-type transmission with fluid control and lubricating circuits. A monitoring system senses the fluid pressure in the lubricating circuit, the hydraulic fluid temperature and the engine speed. The sensed pressure is compared to a temperature and engine speed-compensated alarm value. Alarm signals are generated when the sensed pressure is continuously below the alarm value for a certain period. The alarm is disabled when the engine speed falls below a non-zero threshold level.

Abstract: A device for indicating the flow of gases includes a vertically extending conduit section in which is disposed a ball. The ball seats on a lower seat at zero or minimum gas flow, and on an upper seat at maximum sensed gas flow. The upper seat is configured to permit essentially unrestricted gas flow when the ball is seated on it.Electrical means are associated with either the bottom seat and/or the top seat and co-acts with the ball to sense either minimum gas flow or maximum gas flow, and generate a signal responsive thereto.

Abstract: A pressure transducer, such as a microphone, is placed in proximity to the blades of a fan, such as a fan used to cool electronic equipment. As each blade passes the transducer, a pressure wave is generated that is converted into an electrical pulse by the transducer. Circuitry responsive to those pulses signals an alarm if the fan is not operating properly.

Abstract: A control device in an anesthetic administering system which senses the dangerous condition of nitrous oxide flowing to the patient's breathing mask in the absence of oxygen flow to the mask and provides a warning signal so the condition is known and, thus, is correctable.

Abstract: A control system for a fume hood, wherein limit switches sense the position of the sash, and pressure and light sensors monitor pressure changes in the fume hood and ambient light. A low volume fan continously draws air through the fume hood. When the sash is opened the high volume fan is actuated. Air flow is monitored as the sash position is changed; and an alarm system is actuated when an unsafe condition exists.

Abstract: A system for sensing flow faults in a membrane system for intravenous fluid introduction is provided. A scanner is pulsed to generate reflected energy signals representative of the position of a membrane within a chamber. The scanner is pulsed both before and after the membrane is commanded to move within the chamber. The signals are then compared by an electronic circuit to determine the difference between them. If there exists a sufficiently large difference between the signals, this indicates that the membrane is moving in response to the command signals and the system is functioning properly. If there exists little or no difference between the signals, this indicates that there is a flow fault in the system, and an alarm is sounded.