The application provides an electrical system with online sampling and check function and its check method for high-voltage and medium-voltage electrical equipment, including electrical equipment, gas density relay, gas density sensor, temperature regulation mechanism, online check contact signal sampling unit and intelligent control unit. The temperature rise and fall of the temperature compensation element of the gas density relay is regulated through the temperature regulation mechanism to enable the contact action of the gas density relay of electrical equipment. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site, which greatly improves the reliability of the power grid and the work efficiency, and reduces the O&M cost. At the same time, it also realizes the mutual self-inspection between gas density relay and gas density sensor, and further realizes the maintenance-free.

The application provides an electrical system with online sampling and check function and its check method for high-voltage and medium-voltage electrical equipment, including electrical equipment, gas density relay, gas density sensor, temperature regulation mechanism, online check contact signal sampling unit and intelligent control unit. The temperature rise and fall of the temperature compensation element of the gas density relay is regulated through the temperature regulation mechanism to enable the contact action of the gas density relay of electrical equipment. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site, which greatly improves the reliability of the power grid and the work efficiency, and reduces the O&M cost. At the same time, it also realizes the mutual self-inspection between gas density relay and gas density sensor, and further realizes the maintenance-free.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on a head-curve relation characterizing the centrifugal pump. The head-curve relation relates the fuel density to the rotational frequency, the flow rate, and pressures at the two different points or the differential pressure between the two different points.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on a head-curve relation characterizing the centrifugal pump. The head-curve relation relates the fuel density to the rotational frequency, the flow rate, and pressures at the two different points or the differential pressure between the two different points.

A viscometer includes first and second capillaries and a valve. In a first state, the valve connects the second capillary to a first fluid injector via the first capillary. In a second state, the valve connects the second capillary to a second fluid injector. A controller receives data indicative of respective pressure drops within the first and second capillaries, and generates a pressure ratio signal therefrom. The controller analyzes the pressure ratio signal to determine an end of a transition between a first equilibrium when the valve is in the first state, and a second equilibrium when the valve is in the second state. The controller defines a measurement window based on the transition end, and therein determines a viscosity of the second fluid based on the pressure ratio signal. The first fluid is a solvent, and the second fluid is a solution of a same solvent and a solute.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on an empirically-determined head-curve relation corresponding to the centrifugal pump. The head-curve relation is empirically determined during a characterization phase. The empirically-determined head-curve relation relates the density of the aircraft fuel to the rotational frequency, the flow rate, and the pressures at the two different points.

Apparatus and associated methods relate to simultaneously pumping and measuring density of an aircraft fuel. The aircraft fuel is pumped by a centrifugal pump having an impeller. A rotational frequency of the impeller is determined while the centrifugal pump is pumping the aircraft fuel. Flow rate of the aircraft fuel through the centrifugal pump is sensed. Pressure of the aircraft fuel is measured at two different points within or across the centrifugal pump or a differential pressure is measured between the two different points while the centrifugal pump is pumping the aircraft fuel. Density of the aircraft fuel is determined based on an empirically-determined head-curve relation corresponding to the centrifugal pump. The head-curve relation is empirically determined during a characterization phase. The empirically-determined head-curve relation relates the density of the aircraft fuel to the rotational frequency, the flow rate, and the pressures at the two different points.

The application provides a gas density relay with online self-check function and its check method, which are used for high voltage and medium-voltage electrical equipment. The gas density relay includes a gas density relay body, a first pressure sensor, a temperature sensor, a force measuring sensor, a driving contact action mechanism and an intelligent control unit. The driving contact action mechanism is configured to directly or indirectly drive the signal action mechanism of the gas density relay body to displacement, so that the gas density relay body will have contact signal action. The intelligent control unit will detect the alarm and/or blocking contact signal action value and/or return value of the gas density relay body according to the density value when the contact acts. Checking the gas density relay can be completed without maintainer coming to the site, which improves the reliability of the power grid, improves the efficiency, reduces the operation and maintenance cost, and can implement the maintenance free of the gas density relay.

The application provides a modification of gas density relay, a gas density relay with online self-check function and its check method for high-voltage and medium-voltage electrical equipment. The gas density relay includes a gas density relay body, a gas density sensor, a pressure regulating mechanism, a valve, an online check contact signal sampling unit and an intelligent control unit. The pressure is increased or decreased by the pressure regulating mechanism to enable the contact action of the gas density relay body. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value of the gas density relay body according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site. It has remote reading function to realize free maintenance and significantly improve the reliability of the power grid and the work efficiency, as well as reduces the O&M cost.

The application provides a modification of gas density relay, a gas density relay with online self-check function and its check method for high-voltage and medium-voltage electrical equipment. The gas density relay includes a gas density relay body, a gas density sensor, a pressure regulating mechanism, a valve, an online check contact signal sampling unit and an intelligent control unit. The pressure is increased or decreased by the pressure regulating mechanism to enable the contact action of the gas density relay body. The contact action is transmitted to the intelligent control unit through the online check contact signal sampling unit. The intelligent control unit detects the alarm and/or blocking contact signal operating value and/or return value of the gas density relay body according to the density value of the contact action; the check of the gas density relay can be completed without maintenance personnel on site. It has remote reading function to realize free maintenance and significantly improve the reliability of the power grid and the work efficiency, as well as reduces the O&M cost.