79results about How to "Accurate flow measurement" patented technology

A system and method for controlling a flow of a fluid using a multi-mode control algorithm is described. The method includes disengaging and engaging a feedback control loop that controls a valve of the mass flow controller based upon a rate of pressure change of the fluid. The method also includes calculating a valve position of the valve based on pressure measurements when the feedback control loop has been disengaged and characterization data that characterizes the mass flow controller, and determining, when the feedback control loop is first re-engaged, a difference between a measured flow rate and a flow set point. An adjustment to the characterization data is applied based upon the difference to improve an accuracy of the calculation of the valve position when the feedback control loop is disengaged again.

An ultrasonic wave transmitting and receiving unit includes: a piezoelectric member supporting plate; an acoustic matching member fixed to one surface of the piezoelectric member supporting plate; a piezoelectric member fixed to the other surface. Moreover, the ultrasonic wave transmitting and receiving unit includes: an insulating vibration suppressing member integrally formed in such a manner as to cover the piezoelectric member and the piezoelectric member supporting plate, wherein the insulating vibration suppressing member has a hole reaching the piezoelectric member supporting plate.

The invention discloses a method for calculating steam admission enthalpy of an air-cooling condenser of a direct air-cooling unit. The method specifically includes the first step of measuring the flow of condensed water entering a deaerator, the steam leakage flow of a front shaft seal and a rear shaft seal of a high pressure cylinder and the steam leakage flow of a front shaft seal and a rear shaft seal of an intermediate pressure cylinder, the steam admission flow of a low pressure shaft seal, the steam leakage flow of a steam admission valve rod of the high pressure cylinder and the steam leakage flow of a steam admission valve rod of the intermediate pressure cylinder, and the flow of seal water entering a feed pump; the second step of calculating the steam extraction flow, the water feed flow, the main steam flow, the high pressure cylinder exhaust steam flow and the reheat steam flow from the first section to the fourth section according to energy balance and mass balance of a high pressure heater and the deaerator; the third step of calculating the steam extraction flow from the fifth section to the seventh section according to heat balance and mass balance of a low pressure heater, and calculating exhaust steam energy and exhaust steam flow of the lower pressure cylinder of a turbine according to energy balance and mass balance of the turbine; the fourth step of calculating exhaust steam enthalpy of the low pressure cylinder, namely, the steam admission enthalpy of the air-cooling condenser, and enabling the steam admission enthalpy to serve as a benchmark for calculating heat load of the air-cooling condenser. The measuring results can be more accurate.

A measuring passage includes: an inflow aperture opening onto a vicinity of an end portion of a surface of a main body portion that is perpendicular to a direction of flow of a main flow of a measured fluid so as to be facing upstream; and an outflow aperture opening onto an end surface of the main body portion in a direction of projection. A first passage extends from the inflow aperture in the direction of flow of the main flow to a first bend portion, a second passage extends from the first bend portion so as to be perpendicular to the direction of flow of the main flow toward the circuit housing portion to a second bend portion, a third passage extends from the second bend portion in the direction of flow of the main flow to a third bend portion, a fourth passage extends from the third bend portion in a direction that is perpendicular to the direction of flow of the main flow in a direction away from the circuit housing portion, and a fifth passage extends from the fourth bend portion in a reverse direction to the direction of flow A of the main flow and is connected to the outflow aperture.

The related verification method for pressure-difference measurement device comprises: 1) given static pressure P and pressure difference deltaP, calculating the strain volume deltaV and the travel deltaH of fine-tuning pitons (5, 6) connected between high and low pressure room (2, 3); 2) controlling pitons movement by deltaH to change gas volume in (2, 3) and produce real pressure difference deltaP' determined by real deltaH'; 3) when deltaH = deltaH' and deltaP = deltaP', acting the measurement device (1) to complete one-time verification. This invention satisfies JJG882-2004 standard, fit to any P and deltaP, and needs no special requirement for environment.

There is a need for providing a flow sensor with metal film resistor that improves detection sensitivity using a metal film for a resistance heat detector and a resistance temperature detector. The flow sensor with metal film resistor is structured to form a resistance heat detector, a resistance temperature detector for resistance heat detector for measuring temperature of the resistance heat detector, an upstream resistance temperature detector, a downstream resistance temperature detector, and an air resistance temperature detector on a silicon substrate. Plural floating-island insulators are provided for the resistance heat detector and within wiring thereof.

An electromagnetic flow meter for measuring flow rate of a fluid passing therethrough includes a conduit defining a fluid inlet, a fluid outlet and a measuring section positioned between the inlet and the outlet. The flow meter also includes a single coil for generating a magnetic field across the measuring section and electrodes for detecting induced electrical potential due to the fluid passage. The flow meter also includes means for conditioning the flow through the measuring section. The combination of the single coil and the flow conditioning means provides a flow meter with a desired level of accuracy. The single coil and the electrodes may be arranged so that the integral of a weight function, which defines the sensitivity of the flow meter to fluid velocity through different parts of the measuring section, over the first half of a measuring section closest to the coil is between 0.4 and 1.3 times the integral of the weight function over the other half of the measuring section.

The purpose of the invention is improving the environment-tolerated performance for the matching layer in a supersonic wave transceiver and maintaining the transceiving characteristic of the supersonic wave transceiver. The supersonic wave transceiver of the invention and the piezoelectrics (4) which is arranged at the top inner surface of a metal columnar shell (2) have the electronically-connecting state; and the top of the supersonic wave transceiver in the sealing state is arranged with the vocal matching layer (5) formed by the porous bodies for improving the sensibility for receiving the supersonic wave; the supersonic wave transceiver (1) has a protective cover (7) for covering the lateral wall periphery of the metal columnar shell (2) and the vocal matching layer (5); the top of the protective cover (7) can form the shielding potion for avoiding the destroy of the vocal matching layer (5) in the range of stated opening area which can assure the area of the relevant vocal matching layer (5).

A flow cassette has a housing with an inlet and an outlet and a passage therebetween. The flow cassette also has a temperature sensor disposed within the passage and configured to measure the temperature of a fluid flowing through the passage, a flow rate sensor disposed within the passage and configured to measure a flow rate of the fluid flowing through the passage, and a processor coupled to the temperature sensor and flow rate sensor. The processor is configured to accept measurements of temperature and flow rate from the temperature sensor and flow rate sensor, respectively, and provide a compensated flow rate.

A flow rate measurement device includes a turbulence reduction component having opening portions and disposed between a measurement channel and a pair of hole portions across which a pair of ultrasonic transceivers are disposed from the measurement channel. The pair of opening portions of the turbulence reduction component each have frame pieces which are substantially identical in width. This makes it possible to reduce, with small attenuation of ultrasound, the occurrence of turbulence that is attributable to entrained flows in the pair of hole portions and is a cause of measurement error, thereby ensuring measurement accuracy.

A blood treatment apparatus, including a blood treatment unit configured to receive untreated blood and fresh blood treatment fluid, and emit treated blood and used blood treatment fluid, a pair of fluid pumps configured to pass blood treatment fluid through the blood treatment unit, a pair of blood pumps configured to extract untreated blood from a blood source, pass extracted blood through the blood treatment unit and deliver treated blood to a target vessel, each blood pump including a pump chamber and a flexible member separating the pumping chamber into a first blood accumulating container and a second working fluid accumulating container where the flexible member is configured to vary a volume relationship between the first and the second accumulation containers. A control unit and a measuring device are configured to emit a feedback signal indicative of the amount of working fluid received into, or discharged from at least one of the second accumulation containers whereby the pumped mass or volume of working fluid is determined by the control unit at an arbitrary position of the flexible member.

A Coriolis effect device includes a housing defining an interior chamber having a central axis, an inlet, an outlet, a leading disc and a trailing disc. Each disc is supported for oscillatory movement within the interior chamber of the housing. The leading disc defines a leading flow path in fluid communication with the inlet and interior chamber, wherein a portion of the leading flow path extends radially with respect to the central axis. The trailing disc is axially spaced from the leading disc. The trailing disc defines a trailing flow path in fluid communication with the interior chamber and the outlet, wherein a portion of the trailing flow path extends radially with respect to the central axis. A phase difference between leading and trailing oscillating signals picked up from the disc movement can be used to determine a mass flow rate of fluid passing from the inlet to the outlet.

A portable apparatus for adding a dechlorination agent into a fluid stream prior to discharge and a method for treatment of chlorinated water. The portable apparatus can connect in any part of a fluid flow system. A bypass is provided such that a controlled portion of the fluid stream is diverted to a dechlorination agent. The dechlorination agent dissolves in the bypassed fluid flow. The bypassed, dechlorination agent enriched fluid re-enters and mixes with the fluid flow that was not bypassed. As the two streams mix, the total flow receives the required amount of dechlorination before being discharged into the environment. A valve controls proportional flow of the fluid stream through the bypass.

The present invention is one that suppresses crosstalk caused by switching means adapted to switch transmission/reception between ultrasonic transceivers that are paired, and provided with: a first ultrasonic transceiver and a second ultrasonic transceiver; a transmission circuit that generates a transmission signal for vibrating the first ultrasonic transceiver or the second ultrasonic transceiver; a reception circuit that senses a reception signal from the first ultrasonic transceiver or the second ultrasonic transceiver; first transmission amplifying means adapted to amplify the transmission signal to the first ultrasonic transceiver; first reception amplifying means adapted to amplify a reception signal from the first ultrasonic transceiver; second transmission amplifying means adapted to amplify the transmission signal to the second ultrasonic transceiver; and second reception amplifying means adapted to amplify a reception signal from the second ultrasonic transceiver.

An oxygen therapy monitoring device includes an oscillation chamber with in a gas flow path adapted to pass a gas flow from a source to a breathing interface for a person. The oscillation chamber induces an oscillation in the gas flow that varies as a function of a flow rate of the gas flow. A measurement arrangement measures the oscillation induced in the gas flow and determines the flow rate on the basis of the oscillation that is measured.

To find the propagation time of an ultrasonic wave, a difference occurs between the waveforms received upstream and downstream in a portion where the reception amplitude is comparatively large and it is prevented from being detected as an error of the propagation time. A reception signal is amplified in a reception unit 35 and reception point storage units 38 store the most recent reception point data in a plurality of storage sections in order until the signal level becomes a predetermined value (Vref). An average value of the two zero crossing points before and after the signal level becomes Vref can be adopted as a reception point, the propagation time with a small error of up and down offset, etc., is measured, and it is made possible to realize power saving operation by shortening the measurement time.