Abstract: A mass flow control apparatus is capable of controlling a flow rate of a fluid to a tool. Pressure of the fluid is regulated by a solenoid valve, which receives signals from a control module. Various set points may be inputted to the control module, whereby control module receives pressure sensor signals from across a flow restrictor and adjusts the solenoid valve to control the fluid flow rate to equal a set point.

Abstract: A self-correcting pressure-based mass flow control apparatus includes outlet pressure sensing to enable correction for non-ideal operating conditions. Further the mass flow control apparatus having a fluid pathway, a shutoff valve in the fluid pathway, a reference volume in the fluid pathway, a first pressure measuring sensor in fluid communication with the reference volume, a first temperature measuring sensor providing a temperature signal indicative of the fluid temperature within the reference volume, a proportional valve in the fluid pathway, and a second pressure measuring sensor in fluid communication with the fluid pathway.

Abstract: A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

Abstract: A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

Abstract: A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

Abstract: A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

Abstract: A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

Abstract: A reference volume for use with pressure change flow rate measurement apparatus has an internal structure comprising elements with cross section and length comparable to the cross section and length of adjacent interstitial fluid regions. The reference volume may have one or more heat conduction elements exterior to and in good thermal contact with a corrosion resistant material that defines the internal fluid holding region.

Abstract: A reference volume for use with pressure change flow rate measurement apparatus has an internal structure comprising elements with cross section and length comparable to the cross section and length of adjacent interstitial fluid regions. The reference volume may have one or more heat conduction elements exterior to and in good thermal contact with a corrosion resistant material that defines the internal fluid holding region.

Abstract: A self-correcting pressure-based mass flow control apparatus includes outlet pressure sensing to enable correction for non-ideal operating conditions. Further the mass flow control apparatus having a fluid pathway, a shutoff valve in the fluid pathway, a reference volume in the fluid pathway, a first pressure measuring sensor in fluid communication with the reference volume, a first temperature measuring sensor providing a temperature signal indicative of the fluid temperature within the reference volume, a proportional valve in the fluid pathway, and a second pressure measuring sensor in fluid communication with the fluid pathway.

Abstract: A system comprises a flow restrictor connected to a fluid flow path and located upstream from a chamber. The flow restrictor comprises an adjustable flow restriction aperture defined by the flow path region between a first element and a second element of the flow restrictor, and a drive unit configured to adjust the relative positions of the first element, second element or both to modify the fluid flow path across the aperture. The first or second element provides a curved boundary in the aperture flow path to form a converging region, a region of closest approach and a diverging region, within the flow path. Flow rate may be determined using a reference volume upstream from the flow restrictor.

Abstract: A reference volume for use with pressure change flow rate measurement apparatus has an internal structure comprising elements with cross section and length comparable to the cross section and length of adjacent interstitial fluid regions. The reference volume may have one or more heat conduction elements exterior to and in good thermal contact with a corrosion resistant material that defines the internal fluid holding region.

Abstract: A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

Abstract: A mass flow control apparatus comprising a proportional valve upstream of a flow measurement portion, a pressure sensing element fluidly connected to determine a fluid pressure downstream of the flow measurement portion, and a dynamically adjustable variable valve downstream of the flow measurement portion and adjacent to the pressure sensing element connection. Fluid conductance of the variable valve is adjusted according to a control scheme based upon limitations of the flow measurement portion. Integral flow verification may be enabled with additional fluid pathway elements upstream of the flow measurement portion.

Abstract: A fluid delivery system includes a manifold plate having an upper surface, four vertical sides, and a lower surface opposite the upper surface, where the manifold plate includes a gas inlet, a gas outlet, and a plurality of component receiving stations, one or more component receiving stations located on the upper surface and two or more component receiving stations located on the lower surface. The manifold plate also includes a plurality of internal fluid passageways interconnecting the gas inlet, the plurality of component receiving stations, and the gas outlet. The system also includes a plurality of active fluid components, one active fluid component coupled to a corresponding one component receiving station on the manifold plate. The fluid delivery system can be configured having a single channel or a dual channel.

Abstract: A fluid delivery system includes a manifold plate having an upper surface, four vertical sides, and a lower surface opposite the upper surface, where the manifold plate includes a gas inlet, a gas outlet, and a plurality of component receiving stations, one or more component receiving stations located on the upper surface and two or more component receiving stations located on the lower surface. The manifold plate also includes a plurality of internal fluid passageways interconnecting the gas inlet, the plurality of component receiving stations, and the gas outlet. The system also includes a plurality of active fluid components, one active fluid component coupled to a corresponding one component receiving station on the manifold plate. The fluid delivery system can be configured having a single channel or a dual channel.

Abstract: An improved flow measuring device, such as a mass flow meter or mass flow controller, providing a high turn-down ratio as compared to prior art devices. In accordance with various embodiments of the invention, a flow sensor includes a sensor flow path that includes one or more restrictions configured to provide the sensor flow path with a non-linear relationship between a pressure drop across the sensor flow path and the flow of fluid through the flow sensor conduit. Such a flow sensor preferably achieves a high turn-down ratio by way of a variable bypass ratio that is directly proportional to the sensor tube mass flow rate so that the turn-down ratio of the mass flow controller will be ideally proportional to the square of the turndown achievable by the flow sensor conduit fluid sensing portion alone. In some embodiments, the restriction can be employed as a part of a fluid seal having an orifice and disposed between a flow sensor portion of a flow meter and a bypass portion of the flow meter.

Abstract: An improved flow measuring device, such as a mass flow meter or mass flow controller, providing a high turn-down ratio as compared to prior art devices. In accordance with various embodiments of the invention, a flow sensor includes a sensor flow path that includes one or more restrictions configured to provide the sensor flow path with a non-linear relationship between a pressure drop across the sensor flow path and the flow of fluid through the flow sensor conduit. Such a flow sensor preferably achieves a high turn-down ratio by way of a variable bypass ratio that is directly proportional to the sensor tube mass flow rate so that the turn-down ratio of the mass flow controller will be ideally proportional to the square of the turndown achievable by the flow sensor conduit fluid sensing portion alone. In some embodiments, the restriction can be employed as a part of a fluid seal having an orifice and disposed between a flow sensor portion of a flow meter and a bypass portion of the flow meter.

Abstract: A thermal mass flow meter associated with an inclination sensor that detects an angle of inclination of at least one portion of a thermal mass flow sensor relative to at least one reference axis. Based upon the detected angle of inclination, the output signal of the mass flow meter that is indicative of the mass flow rate of fluid through the sensor may be compensated to account for any inaccuracies relating to the orientation in which the mass flow meter is installed. Inaccuracies for which compensation may be provided include thermal siphoning effects and fluid buoyancy effects. By compensating for such inaccuracies, the mass flow meter may be used in any orientation, and/or may be used in non-inertial (e.g., accelerating) environments. The flow meter may be used as a stand alone device, or incorporated in a thermal mass flow controller.

Abstract: An ultrasonic flow meter includes a conduit, a first ultrasonic transducer, a second ultrasonic transducer, and a controller. The first ultrasonic transducer is disposed at a first position about a first portion of the conduit to transmit a first ultrasonic signal and to receive a second ultrasonic signal. The second ultrasonic transducer is disposed at a second position about a second portion of the conduit that is spaced apart from the first position along a length of the conduit to transmit the second ultrasonic signal and to receive the first ultrasonic signal. The controller is configured to cross-correlate the first and second received ultrasonic signals and generate a resulting time-domain signal, analyze the resulting time-domain signal to determine a difference in transit time between the first and second received ultrasonic signals, and calculate a rate of flow of a fluid in the conduit based upon the determined difference.