A flow control device equipped with flow monitor includes a build-down type flow monitor unit provided on an upstream side, a flow control unit provided on a downstream side of the build-down type flow monitor unit, a signal transmission circuit connecting the build-down type flow monitor unit and the flow control unit and transmitting a monitored flow rate of the build-down type flow monitor unit to the flow control unit, and a set flow rate value adjustment mechanism being provided in the flow control unit and adjusting a set flow rate of the flow control unit based on the monitored flow rate from the build-down type flow monitor unit.

A flow control device equipped with flow monitor includes a build-down type flow monitor unit provided on an upstream side, a flow control unit provided on a downstream side of the build-down type flow monitor unit, a signal transmission circuit connecting the build-down type flow monitor unit and the flow control unit and transmitting a monitored flow rate of the build-down type flow monitor unit to the flow control unit, and a set flow rate value adjustment mechanism being provided in the flow control unit and adjusting a set flow rate of the flow control unit based on the monitored flow rate from the build-down type flow monitor unit.

A flow sensing module is provided for determining a flow rate of a fluid flowing through a flow channel. The flow sensing module may include an integrated flow restrictor, sometimes including a plurality of concentric ribs defining a plurality of orifices shaped to match the curvature of the wall of the flow channel. A first sensing port may open into the flow channel upstream of the flow restrictor, and a second sensing port may open into the flow channel downstream of the flow restrictor. A flow rate of a fluid flowing through the flow channel may be determining using a differential pressure between the first and second ports created by the flow restrictor, either using a flow sensor or a pressure sensor. The particular arrangement and relative dimensions of the orifices of the flow restrictor and the pressure ports can result in substantially reduced noise.

A flow sensing module is provided for determining a flow rate of a fluid flowing through a flow channel. The flow sensing module may include an integrated flow restrictor, sometimes including a plurality of concentric ribs defining a plurality of orifices shaped to match the curvature of the wall of the flow channel. A first sensing port may open into the flow channel upstream of the flow restrictor, and a second sensing port may open into the flow channel downstream of the flow restrictor. A flow rate of a fluid flowing through the flow channel may be determining using a differential pressure between the first and second ports created by the flow restrictor, either using a flow sensor or a pressure sensor. The particular arrangement and relative dimensions of the orifices of the flow restrictor and the pressure ports can result in substantially reduced noise.

A collar is provided for use with a fluid flow sensor to reduce condensation of a moist gas flowing through the fluid flow sensor. The collar comprises a body defining an interior that defines an airspace between the collar and the housing of the fluid flow sensor when the collar is positioned on the fluid flow sensor. The collar also includes a heat source secured to the body and adapted to heat air contained within the airspace to consequently heat the housing of the fluid flow sensor and the interior surfaces of the sensor to reduce condensation of the moist gas.

A collar is provided for use with a fluid flow sensor to reduce condensation of a moist gas flowing through the fluid flow sensor. The collar comprises a body defining an interior that defines an airspace between the collar and the housing of the fluid flow sensor when the collar is positioned on the fluid flow sensor. The collar also includes a heat source secured to the body and adapted to heat air contained within the airspace to consequently heat the housing of the fluid flow sensor and the interior surfaces of the sensor to reduce condensation of the moist gas.

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).

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 device (20) for measuring the flow rate of ink sent to a print head of an ink jet printer, comprising: a restriction (22) of the diameter of the flow of ink, arranged in the path thereof, sensors (26, 28) for measuring the pressure difference (P.sub.in−P.sub.out), between the pressure of fluid upstream of the restriction (P.sub.in) and the pressure of ink downstream of the restriction (P.sub.out).

A multi-hole orifice plate for flow control includes an orifice plate for controlling the flow rate of a fluid, wherein the opening area of one orifice necessary for the passage of a predetermined flow rate of fluid is divided to provide a plurality of orifices having a total opening area equal to said opening area.