50results about "Fluid pressure measurement by thermal means" patented technology

A heat conduction-type sensor corrects (calibrate) effects of a temperature of a measurement target fluid and a type of the fluid on a measurement value in measurement of a flow velocity, a mass flow, or an atmospheric pressure. Also provided is a thermal flow sensor and a thermal barometric sensor with this correcting function, high sensitivity, simple configuration, and low cost. At least two thin films that are thermally separated from a substrate through the same cavity are provided, one thin film comprises a heater and a temperature sensor, and the other thin film comprises at least one temperature sensor, the temperature sensors being thin-film thermocouples. The thin film is arranged in proximity so that it is heated only through the measurement target fluid by heating of the heater. A calibration circuit calculates and compares quantities concerning heat transfer coefficients of a standard fluid and the unknown measurement target fluid.

A detector for monitoring the low levels of differential pressures and the rate of mass flow rate of gas (air, e.g.) in a duct. The sensor's temperature is maintained at a constant gradient above temperature of the flowing gas, typically 4-7° C. higher. The detector consists of two thermally decoupled sensors—one is the air temperature sensor and the other is a temperature sensor coupled to a heater. The sensors are connected to an electronic servo circuit that controls electric power supplied to the heater. The sensors are positioned outside of the air duct and coupled to the duct via a relatively thin sensing tube protruding inside the duct. The end of the tube has an opening facing downstream of the gas flow, thus being exposed to a static gas pressure. The detector can be employed in fuel burners of the HVAC systems, internal combustion engines, medical equipment to control flow of anesthetic gases, in the security systems to monitor minute changes in air pressure resulted from opening and closing of doors and windows in a protected facility.

A detector for monitoring the low levels of differential pressures and the rate of mass flow rate of gas (air, e.g.) in a duct. The sensor's temperature is maintained at a constant gradient above temperature of the flowing gas, typically 4-7° C. higher. The detector consists of two thermally decoupled sensors—one is the air temperature sensor and the other is a temperature sensor coupled to a heater. The sensors are connected to an electronic servo circuit that controls electric power supplied to the heater. The sensors are positioned outside of the air duct and coupled to the duct via a relatively thin sensing tube protruding inside the duct. The end of the tube has an opening facing downstream of the gas flow, thus being exposed to a static gas pressure. The detector can be employed in fuel burners of the HVAC systems, internal combustion engines, medical equipment to control flow of anesthetic gases, in the security systems to monitor minute changes in air pressure resulted from opening and closing of doors and windows in a protected facility.

Testing apparatus and method for testing compressed gas dispensing stations where a back pressure regulator is used to imitate filling of receiving vessels without the need for receiving vessels. A mass flow sensor measures the mass of compressed gas dispensed to the testing apparatus, and a controller calculates the pressure for the back pressure regulator to imitate filling of a receiving vessel.

A device for measuring a pressure of a gas in a pollution control or energy storage system, including: a housing including an inlet and an outlet; a compound disposed inside the housing and configured to absorb at least one portion of gas entering the housing through the inlet, the non-absorbed portion of gas exiting the housing via the outlet; at least one sensor configured to measure a temperature of the compound; a processing unit configured to determine the pressure of the gas by using the temperature measurement from the sensor and a predefined pressure / temperature ratio.

A physical quantity sensor includes: a diaphragm that can deflect and deform; a peripheral wall portion that is disposed around the diaphragm and has a thickness increasing in a direction away from the diaphragm; a deflection amount sensor that detects a deflection amount of the diaphragm; and a temperature sensor that is disposed in the peripheral wall portion.

The design and manufacture method of a pressure sensor utilizing thermal field sensing with a thermal isolated membrane of a diaphragm structure is disclosed in the present invention. This device is made with silicon micromachining (a.k.a. MEMS, Micro Electro Mechanical Systems) process for applications of pressure measurement with large dynamic range, high accuracy and high stability during temperature variation. This device is applicable for all types of pressure metrology. The said thermal field pressure sensing device operates with thermistors on a membrane of the diaphragm structure made of silicon nitride with a heat isolation cavity underneath or a single side thermal isolated silicon nitride membrane with a reference cavity. This device can be seamlessly integrated with a thermal flow sensor with the same process.

A heat conduction type barometric sensor has high sensitivity and high accuracy that has simple structure and circuit configuration and can measure a barometric pressure in the range of a very low barometric pressure to ≧1 atm using one sensor chip. The sensor includes a cantilever-shaped thin film provided with a thin-film temperature sensor, a heating element, and an excitation element. The excitation element utilizes warpage and bending based on a difference in thermal expansion between two main layers constituting the thin film during intermittent heating by a thin-film heater as the heating element. The two main layers are a silicon layer and a thermally oxidized film of silicon which are significantly different from each other in the coefficient of thermal expansion. A circuit in which the sensitivity is enhanced by the integration of a seebeck current for a predetermined period of time can be also provided.

The invention relates to a pressure measuring device and method, in particular to a non-contact pressure measuring device and method, which are suitable for pressure measurement of a gas cylinder module in a rocket attitude and orbit control power system and are also generally suitable for other pressure containers with pressure measurement requirements. The technical problems that the sealing reliability and safety of an original structure are reduced and long-term pressure monitoring is not facilitated in the prior art are solved. The non-contact pressure measuring devicecomprises a cable, ademodulator, a strain sensor and a temperature sensor, wherein the strain sensor and the temperature sensor are respectively adhered to the outer surface of the pressure-bearing shell of the gas cylinder module to be measured; the strain sensor and the temperature sensor are connected with the demodulator through the cable; and the demodulator is provided with a calibration value input equipmentinterface. The method is carried out by using the device.

The invention discloses a method for inversion of sea surface air pressure by MWTS-II and MWHTS fusion. The method comprises the following steps: establishing a brightness temperature matching pair ofMWTS-II observation brightness temperature and MWHTS observation brightness temperature in time and space; establishing a matching data set of the brightness temperature matching pair and the sea surface air pressure in time and space, and forming an analysis data set and a verification data set; training a BP neural network by utilizing the analysis data set, and sorting contribution of the observation brightness temperature of each channel to inversion of sea surface air pressure according to a training result; increasing the observation brightness temperatures of the channels one by one according to the descending order of the contribution of the observation brightness temperature of each channel to inversion of the sea surface air pressure, training a BP neural network, and an optimalchannel combination for inversion of the sea surface air pressure by MWTS-II and MWHTS fusion can be established according to the training result. Compared with a single satellite-borne microwave radiometer for inversion of the sea surface air pressure, the method can acquire higher inversion precision, and is simple and easy to operate.

The invention discloses a method for testing the sensitivity of MWTS-II to sea surface air pressure based on natural atmosphere, and belongs to the technical field of microwave remote sensing. The method comprises the following steps of: establishing a matching data set of MWTS-II observation brightness temperature and a natural atmosphere data set, and establishing a clear sky matching data set;calculating an MWTS-II channel weight function based on the clear sky matching data set, and respectively establishing a clear sky adjustment data set for each channel of the MWTS-II according to thedistribution rule of atmospheric layers where the peak value of the weight function of each channel of the MWTS-II is located; according to the atmospheric layers where the peak value of the weight function of each channel of the MWTS-II is located, based on the clear sky adjustment data sets, respectively establishing a test data set for testing the sea surface air pressure sensitivity for each channel of the MWTS-II; as for each channel of the MWTS-II, respectively establishing the change relation of the observation brightness temperature of each channel of the MWTS-II along with the sea surface air pressure, and completing the sensitivity test of the MWTS-II on the sea surface air pressure. According to the method, the change relation of the observation brightness temperature of each channel of the MWTS-II along with the sea surface air pressure can be reflected more truly, the sensitivity of the sea surface air pressure can be tested more accurately, and the operation is simple andeasy to implement.

An apparatus and a method for measuring an altitude of a terminal which can correct an altitude error according to temporal and spatial changes are provided. The apparatus includes an atmospheric pressure measuring unit for measuring an atmospheric pressure from a barometer included in the terminal, a position determiner for measuring position information of the terminal, and a controller for, when a reference atmospheric pressure reception period is not generated, predicting a current reference atmospheric pressure by using previously received reference atmospheric pressures and measuring a current altitude by using the predicted reference atmospheric pressure and the measured atmospheric pressure.

A testing apparatus and method for testing compressed gas dispensing stations are provided, wherein a back pressure regulator is used to imitate filling of receiving vessels without the need for receiving vessels. A mass flow sensor measures the mass of compressed gas dispensed to the testing apparatus, and a controller calculates the pressure for the back pressure regulator to imitate filling ofa receiving vessel.

The invention provides a device and method for measuring continuous distribution of pore pressure and a quantitative evaluation method for tensile stress, belonging to the field of solid-phase output control of deep high-pressure gas wells. The device includes a cylinder body, a thermal imaging instrument, a compressor, a gas tank and data acquisition system, the inlet of the cylinder is provided with a gas inlet pressure sensor, the gas outlet is provided with a gas outlet pressure sensor, the gas inlet pressure sensor, the gas outlet pressure sensor, the flow sensor and the thermal imaging instrument are all connected to the data acquisition system through a data line connect. This method starts from the method of accurately predicting pore pressure, and considers the tensile stress caused by poroelasticity and fluid drag at the same time, and finally obtains the accurate radial tensile stress. Based on the tensile failure criterion, the solid phase production conditions are guaranteed Accurate prediction, obtaining continuous pore pressure distribution equations from experiments, ensures the accuracy of tensile stress calculation.

The invention discloses a constant-temperature type hot-film shear stress micro-sensor closed-loop feedback control system, and belongs to the field of sensor measuring instruments. The adopted technical scheme of the invention comprises a hardware circuit design and an algorithm design of the hot-film shear stress micro-sensor closed-loop feedback control system. The hardware circuit is formed bya fixed resistor1, a flexible hot-film shear stress micro-sensor 4, a simulation operational amplifier 6, an instrument operational amplifier 7, a simulation multiplier 8, a microcontroller 9, and alow-noise amplifier 10. The algorithm design comprises threshold setting, design of an integration link and design of a proportion link. According to the constant-temperature type hot-film shear stress micro-sensor closed-loop feedback control system, through the design form of four-wire system measurement of the sensor resistance, the measuring error caused by a lead wire resistance of the hot-film shear stress micro-sensor is greatly reduced, and the calibration difficulty of the hot-film shear stress micro-sensor in a practical application process is reduced; besides, through dynamic and real-time adjustment of the algorithm of the microcontroller 9, the problems that according to a conventional design scheme, a self-excitation state is entered due to large-range change of the flow velocity of a flow field, and normal operation is failed are avoided.

The invention belongs to the field of ultrahigh pressure detection and relates to a pressure detection method based on a metastable phase rare-earth nickel-based oxide. According to the pressure detection method, a rare-earth nickel-based oxide with a thermodynamic metastable phase structure is used as a pressure sensitive material in a pressure detector; and pressure measurement in a high-pressure and ultrahigh-pressure spectral range is realized by utilizing a characteristic that the rare-earth nickel-based oxide changes sensitively along with pressure in the high-pressure and ultrahigh-pressure range and the relation of the change of resistivity and a resistance temperature coefficient along with pressure. Compared with previous pressure measuring methods, the method can realize pressure measurement in the spectral range, and realize the cross validation of pressure measurement in the high-pressure and ultrahigh-pressure range through the comprehensive characterization of the resistivity and a resistance temperature change rate, thereby greatly improving pressure measurement precision in the high-pressure range. The method of the invention can be further applied to the aspects of high-pressure detection, deep sea pressure measurement, geological pressure measurement and the like.