1612results about "Level indicators by pressure measurement" patented technology

A method of treating a tissue site is provided. The method includes applying a reduced pressure to a tissue site with a reduced pressure source. A source pressure is monitored at the reduced pressure source, and a differential pressure is determined between the source pressure and the desired tissue site pressure. If a blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a first maximum differential pressure. If no blockage is present between the reduced pressure source and the tissue site, the differential pressure is limited to a second maximum differential pressure.

A reduced pressure treatment system is provided that includes a canister that is fluidly connected to a tissue site and is configured to receive fluid drawn from the tissue site under the influence of a reduced pressure. A reduced pressure source provides the reduced pressure and is fluidly connected to the tissue site by a fluid communication path, which may include a source conduit, the canister, and a target conduit. A sensing device communicates with the source conduit and is configured to sense a pressure in the source conduit. A valve communicates with the source conduit and is configured to vent the reduced pressure. A processing unit communicates with the sensing device and the valve and is configured to open the valve for a selected amount of time, determine a decay of reduced pressure, and determine a fill status of the canister based on the decay of reduced pressure.

A method and apparatus for remote laser-based detection of gas at levels exceeding natural background levels preferably utilizing wavelength modulated tunable diode laser absorption spectroscopy. In a preferred embodiment, background gas and noise are estimated using statistical moving average and variance calculations. Gas concentration length measurements resulting from the spectroscopy are preferably compared in real-time or near-real-time to the sum of the background and noise estimates and an alarm limit to detect gas presence of concern. Gas levels exceeding this detection threshold are preferably indicated by a prolonged output tone with a pitch indicative of the magnitude of the gas measurement, and gas levels below the detection threshold are preferably indicated by silence.

An improved pressure activated control apparatus is provided for sensing fluid pressure and triggering one or more switches in response to the fluid pressure, as desired. The apparatus is designed to be placed within a fluid of a reservoir. The apparatus includes a first resilient member, such as a pliable rolling diaphragm or bellofram, having an outer surface exposed to the fluid and responsive to the fluid pressure. The pressure activated control apparatus includes a second resilient member, such as a spring with a chosen spring constant, k, that provides a biasing force against the diaphragm that is opposite the fluid pressure. A transducer is operative to monitor changes in pressure of gases within the apparatus causes by movement of the diaphragm. A controller is responsive to the transducer and selectable fluid level thresholds to activate pumps and/or valves for adjusting the level of the fluid in the reservoir.

System for monitoring oil level and detecting leaks in power transformers, reactors, current and potential transformers, high voltage bushings and the like, notably for a system that through the use of sensors and other electronic components measures and monitors transformers and similar equipment in real time, filled with insulating oil, with greater precision and without need for floats or mobile mechanical parts, while presenting countless facilities in the sense of making level monitoring more reliable and safer, highlighting the level error calculations, oil leak detection alarm, excess oil detection alarm during the equipment filling process and calculation of tendencies of evolution for levels among other facilities.

A system and method for performing tissue therapy may include applying a reduced pressure to a tissue site of a patient. A fluid parameter associated with applying a reduced pressureto the tissue site may be sensed. An audible fluid leak location sound may be generated in response to sensing the fluid parameter. The audible fluid leak location sound may be altered in response to sensing that the fluid parameter changes. By altering the audible fluid leak location sound in response to sensing a change of the fluid parameter, a clinician may detect location of a fluid leak at the drape by applying force to the drape. The force applied to the drape may be a clinician pressing a finger onto an edge of the drape.

Fluid supply systems for storage and dispensing of chemical reagents and compositions, e.g., high purity liquid reagents and chemical mechanical polishing compositions used to manufacture microelectronic device products, having capability for detection of an empty or near-empty condition when the contained liquid is at or approaching depletion during dispensing operation. Fluid delivery systems employing empty detect arrangements are described, including pressure transducer monitoring of dispensed material intermediate the supply package and a servo-hydraulic dispense pump, or monitoring of dispenser chamber replenishment times in a dispenser being replenished on a cyclic schedule to flow material from the dispenser to a downstream tool utilizing the dispensed material.

Articles and methods for measuring weight of a liquid in a disposable bag bioreactor are presented. In certain embodiments, bioreactor systems described herein include a supported container (e.g., a flexible bag in a reusable housing) for containing a liquid, and at least two pressure indicating sensors operatively associated with the container. A first pressure indicating sensor can be placed near the bottom of the container to measure the total downward force within the container, including the liquid head in the container and the gas pressure above the liquid. The second pressure indicating sensor can be placed near the top of the container to measure only the pressure at the top of or above the liquid. Signals from the pressure indicating sensors can be directed to a control system that receives the signals and calculates a difference between the signals. This difference can be used to determine a volume or a weight of the liquid in the container. Advantageously, real-time weight measurements can be obtained while the system is in operation and continuous flow processes can be monitored. Moreover, in some embodiments, the pressure indicating sensors are isolated from contact with any fluid (e.g., liquid) in the container and, therefore, do not require cleaning after processing of each batch of reactants. Contamination of the process fluid by contact with the pressure indicating sensors can also be avoided.

A hydrogen storage tank for containing solid-state hydrogen storage media, and method for determining the hydrogen fill level in the tank. The tank has at least one compartment for storing the storage media, passages for transporting hydrogen gas to and from the compartment, and a heat distribution system for establishing a substantially uniform temperature in the storage media. A look-up table is generated for the tank that relates hydrogen pressure changes in the tank versus hydrogen fill levels in the tank as a function of temperature. The tank is filled to full capacity by adsorbing hydrogen on the storage media. Thereafter, hydrogen is released from the storage media for a time period during which there is a substantially constant demand on the tank, the change in pressure of the released hydrogen gas is measured, and the look-up table is applied to determine the hydrogen fill level in the tank.

Systems and methods may be provided for monitoring a fuel level of a vehicle. The fuel may be a gaseous fuel, such as natural gas. An electronic control unit may be able to receive a signal from one or more sensors. The electronic control unit may provide a command to drive a fuel gauge to display the fuel level. The electronic control unit may determine the gauge command based on the received signal and a filling compensation scheme. The electronic control unit may be initialized through a user interface. A filling compensation scheme may be selected during initialization. The electronic control unit may be capable of communicating various sensors, gauges, devices, controls and/or other ECUs of varying specifications.

First and second elongated flexible insulated substrates have patterns of resistive liquid level sensor sections along the substrate lengths, each pattern comprising printable resistive ink of the same resistivity (ohms-squared), wherein the patterns can be simultaneously printed upon each substrate to save manufacturing costs. The substrates can be separated by an elongated spacer that couples longitudinal edges of the facing substrates together with an appropriate adhesive. Alternatively, the facing substrates can be folded along a central fold line to form a first longitudinal edge and adhesively joined along a second longitudinal edge opposite the first longitudinal edge. The flexibility of the substrates enables the low manufacturing cost liquid level sensors to be positioned in for example in a highly irregularly shaped vehicle fuel tank. Also, sections of varying lengths to be cut from the rolls on demand by users to form customized lengths of liquid level sensors for numerous applications.

A bedside apparatus and method designed to collect and monitor liquids output from a catheterized patient including an electronic unit and one of a plurality of defined disposable collecting and measuring rigid vessels that may differ in shape and size. Each defined vessel has at least one inlet to connect to a catheter outputting liquid from a patient in order to collect the liquid in the defined vessel. The defined vessel has at least one outlet valve to control draining of liquid from the vessel. An electronic unit has a configuration to receive the defined vessel and to securely mount and hold the defined vessel in a fixed relationship. The electronic unit further has a liquid level sensing device located in juxtaposition to the defined vessel to sense the level of liquid contained in the vessel.

A system for providing different versions of a modularly structured apparatus for determining a physical process quantity, wherein at least two devices to be generated from the system are based on different measuring principles, including a number sensor units (41-48), each sensor unit being designed for detecting a determined physical measuring quantity and for converting said measuring quantity into an electrical measuring signal, wherein at least two of the sensor units are distinguished from each other by their underlying measuring principles; at least one evaluation unit (10), adapted to connect to the sensor units, for evaluating and generating a process quantity signal representing the physical process quantity from the measuring signal of a sensor unit; at least one output unit (13) for outputting the process quantity signal; at least one voltage supply unit (16); and at least one housing unit (22-24) configured to accommodate at least the evaluation unit.

An apparatus for sensing a fluid level that, in one embodiment, is adapted to fit the threads of a fill pipe or vent cap in a storage tank. A first (or upper) part of the assembly is secured in an upper portion of the tank (such as is provided at a threaded vent opening) and includes components to permit sensing pressure at a first location. A second (lower) portion of the assembly sensing pressure at a second location is disposed in a weighted casing. The second portion is coupled to the first portion through a cable that carries a section of tubing. Circuitry disposed in the second portion receives a pressure indication from the upper portion through the tubing, and detects a fluid pressure at both the upper and lower portion of the tank. The difference between the two pressures is indicative of fluid level. This level is then sent back up to the electronics assembly in the first (upper) portion. The electronics assembly can contain a microprocessor and a radio transmitter, such as a cellular or other wireless data network transmitter, to report the fluid level to a remote station such as operated by a fuel supplier. In more particular aspects, the reports of fluid levels can be delayed until periods of significantly less change in fluid level or an indication that use of the tank as stopped, to save battery life.

Fuel gauges for fuel supplies for fuel cells are disclosed. Each fuel gauge has a property that is readable by an electrical circuit. These properties are related to the remaining fuel in the fuel supplies. These properties include, but are not limited to, electrical capacitance, magnetic, semi-conducting resistance, bi-metal resistance, and oscillating magnetic field. These fuel gauges are functional at any fuel supply orientation.

The invention relates to a fiber grating osmotic pressure sensor with low measuring range, comprising a tubular bracket, a housing, a first bragg fiber grating, a second bragg fiber grating, an undulatory mebrane and a specially shaped mebrane, wherein the tubular bracket is in water-tight seal with the housing, the first bragg fiber grating and the second bragg fiber grating are connected in series with each other, and the edges of the undulatory mebrane and the specially shaped mebrane are fixedly arranged on both ends of the tubular bracket; the centers of the undulatory mebrane and the specially shaped mebrane are respectively fixedly arranged on both ends of a connecting rod on which a platform is arranged, the circular undulatory mebrane and the specially shaped mebrane are in water-tight seal with the joint part of the tubular bracket, and the tubular bracket is in water-tight seal with the joint part of the housing; and an adjustable bracket is arranged on the tubular bracket, the joint part of the first bragg fiber grating and the second bragg fiber grating is supported by one end of the adjustable bracket, the adjustable bracket causes the first bragg fiber grating to be in the state of free suspension, and the second bragg fiber grating is fixedly arranged between the other end of the adjustable bracket and the platform in a pre-tight way and is connected with an externally connected optical cable. The invention is mainly used for the detection of low pressure.

According to an exemplary embodiment, the present technique relates to a fuel sensor for determining operational fuel level (h_new) in a fuel tank (14). In the exemplary embodiment, an isolated airspace (44) is created. By monitoring the pressure conditions in the isolated airspace 44 as well as the pressure and temperature conditions in the remainder (42) of the tank (14), the operational fuel level (h_new) may be determined.

The invention discloses an optical fiber F-P pressure sensor and a pressure liquid level sensing device thereof, relating to a type of pressure sensor. The structure of the sensor is that: a pressure film box/plate provided with pressure injection holes is arranged at the center and connected with the periphery of the opening of a supporting member in a sealing way; the center of the bottom of the supporting member is provided with optical fixing holes and pressure balancing holes, and the optical fixing holes are connected with conductive optical fiber; and an extrinsic F-P cavity is arranged between the end face of the conductive optical fiber and the central plane of the pressure film box/plate. The sensor features simple structure, small volume, convenient mounting, high pressure resolution and is very suitable for measuring requirement of small range and high precision; sensitive elements can be replaced conveniently to adapt to the different measuring requirements; the cost is lower and no special demands for light source wavelength exists; the invention is applicable to computation of storage quantity of small chemical liquid and oil stock tank, chemical/oil stock and transportation tank vehicle and other various types of liquid/gas stock and transportation equipment.