The invention relates to a flow-rate measurement assembly for measuring a flow rate of a medium (2) through a measurement pipe (3), comprising at least one differential-pressure producer (4), which is located in the measurement pipe (3) and which effects a drop in the media pressure, which drop depends upon the flow rate, and comprising a differential-pressure measurement transducer (5) for providing a differential-pressure measurement signal (22), which depends upon the difference between the high-pressure-side media pressure and the low-pressure-side media pressure, wherein the difference is a measure of the flow rate of the medium (2), wherein the evaluating unit (10) is designed to determine a relationship between the differential-pressure measurement signal (22) and a characteristic parameter of a fluctuation of the differential-pressure measurement signal (22), to judge the determination of a monotonically decreasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter to be an indication of a clogged high-pressure line (6), and to judge the determination of a monotonically increasing relationship between the differential-pressure measurement signal (22) and the characteristic parameter, the monotonically increasing relationship of which is significantly stronger than the monotonically increasing relationship of an unclogged flow-rate measurement assembly, as an indication of a clogged low-pressure line (8).

A rate-of-change flow measurement device is provided including first pressure sensor, a position control valve with a valve position sensor, a second sensor position and a chamber comprising a part of the flow path of the device, and an isolation valve, arranged in this order along the flow path of the device. The device receives valve position data from the valve position sensor and pressure data from the pressure sensors, and calculates a volume of the chamber at least in part using the valve position data when a calibration of a device-under-test is performed by decreasing a pressure of the chamber or increasing the pressure of the chamber while opening the position control valve to maintain the pressure reading of the first pressure sensor constant to stay at a pressure set point.

A rate-of-change flow measurement device is provided including first pressure sensor, a position control valve with a valve position sensor, a second sensor position and a chamber comprising a part of the flow path of the device, and an isolation valve, arranged in this order along the flow path of the device. The device receives valve position data from the valve position sensor and pressure data from the pressure sensors, and calculates a volume of the chamber at least in part using the valve position data when a calibration of a device-under-test is performed by decreasing a pressure of the chamber or increasing the pressure of the chamber while opening the position control valve to maintain the pressure reading of the first pressure sensor constant to stay at a pressure set point.

A fluid flow sensor includes a hollow cylindrical casing containing a large number of solid spheres of identical diameter, packed tightly together. Fluid inflow and fluid outflow blocks are mounted to opposite ends of the casing, forming a fluid-tight seal. The fluid inflow and outflow blocks each enclose a generally conical fluid chamber tapering from where it meets an end of an interior of the casing to a respective inlet passage or outlet passage. Circular grilles divide the casing from each fluid chamber and retain the spheres in place. A pressure differential across the casing is measured via side passages extending laterally from each fluid chamber. For a given fluid, a given casing diameter and a given sphere diameter, this pressure differential can be converted to a fluid flow rate.

A fluid flow sensor includes a hollow cylindrical casing containing a large number of solid spheres of identical diameter, packed tightly together. Fluid inflow and fluid outflow blocks are mounted to opposite ends of the casing, forming a fluid-tight seal. The fluid inflow and outflow blocks each enclose a generally conical fluid chamber tapering from where it meets an end of an interior of the casing to a respective inlet passage or outlet passage. Circular grilles divide the casing from each fluid chamber and retain the spheres in place. A pressure differential across the casing is measured via side passages extending laterally from each fluid chamber. For a given fluid, a given casing diameter and a given sphere diameter, this pressure differential can be converted to a fluid flow rate.

A method produces a void fraction (VF) error curve which correlates an apparent VF with the actual VF of a multi-phase flow, the method comprising (a) using a device to measure a property of the multi-phase flow from which an apparent VF may be calculated; (b) calculating the apparent VF using the measured property from the device; (c) determining the actual VF of the multiphase flow using a radiometric densitometer; (d) using the values from steps (b) and (c) to calculate the VF error; (e) repeating steps (b) through (d) for all expected flow conditions to generate a VF error curve.

A method produces a void fraction (VF) error curve which correlates an apparent VF with the actual VF of a multi-phase flow, the method comprising (a) using a device to measure a property of the multi-phase flow from which an apparent VF may be calculated; (b) calculating the apparent VF using the measured property from the device; (c) determining the actual VF of the multiphase flow using a radiometric densitometer; (d) using the values from steps (b) and (c) to calculate the VF error; (e) repeating steps (b) through (d) for all expected flow conditions to generate a VF error curve.

In the physical quantity detection device, the occurrence of the measurement error is reduced by suppressing the flow bias in the sub-passage and reducing the resistance in the passage. A physical quantity detection device 30 of the present invention includes a measuring portion 310 disposed in a main passage, a sub-passage 330 that takes a gas to be measured from the main passage, a support member 603 that divides a part of the sub-passage into two flow paths of one surface side and the other surface side in a direction intersecting a passage width direction, and a flow rate detection element 602 disposed on one surface of the support member. The sub-passage includes a straight portion 321 in which the support member is disposed and a downstream curved portion 322 that is curved to one side in the passage width direction of the straight portion. The straight portion is provided with a dividing wall 500 that divides the flow path on the other surface side of the support member into two flow paths on one side and the other side in the passage width direction, and a cross-sectional area of the flow path on one side in the passage width direction is smaller than a cross-sectional area of the flow path on the other side in the passage width direction.

In the physical quantity detection device, the occurrence of the measurement error is reduced by suppressing the flow bias in the sub-passage and reducing the resistance in the passage. A physical quantity detection device 30 of the present invention includes a measuring portion 310 disposed in a main passage, a sub-passage 330 that takes a gas to be measured from the main passage, a support member 603 that divides a part of the sub-passage into two flow paths of one surface side and the other surface side in a direction intersecting a passage width direction, and a flow rate detection element 602 disposed on one surface of the support member. The sub-passage includes a straight portion 321 in which the support member is disposed and a downstream curved portion 322 that is curved to one side in the passage width direction of the straight portion. The straight portion is provided with a dividing wall 500 that divides the flow path on the other surface side of the support member into two flow paths on one side and the other side in the passage width direction, and a cross-sectional area of the flow path on one side in the passage width direction is smaller than a cross-sectional area of the flow path on the other side in the passage width direction.

A device for measuring flow rate of wet gas based on an exempt radioactive source, includes a section of cylindrical pipe and a conical throttle located inside the cylindrical pipe and coaxially arranged therewith. The conical throttle includes a head cone section and a tail cone section arranged to have a common bottom surface. The head cone section faces a wet gas inlet of the cylindrical pipe. An annular gap is defined between the inner wall of the cylindrical pipe and the maximum diameter of the conical throttle for passage of wet gas. An exempt radioactive source block is arranged at the maximum diameter of the conical throttle in such a way that the gamma rays emitted from the radioactive source block can transmit radially through the annular gap to reach the gamma ray detector located outside the cylindrical pipe.