In one embodiment, a method for delivering a gas at a predetermined rate includes providing a gas flow control apparatus comprising a gas flow path extending from a gas inlet to a gas outlet, a proportional valve coupled to the gas flow path, an on/off valve coupled to the gas flow path, a volume being defined between the proportional valve and the on/off valve, and a flow restrictor having a flow impedance located downstream of the proportional valve. The volume is pressurized with the gas to a target set point by opening the proportional valve while the on/off valve is in an off state. Finally, the on/off valve is moved to the on state, delivering gas to the gas outlet.

A substrate processing system includes a substrate processing apparatus and a measurement apparatus. The substrate processing apparatus includes a gas supply unit. The gas supply unit includes a flow rate controller and a secondary valve. The secondary valve is connected to a secondary side of the flow rate controller. The secondary valve is opened when a voltage is output from a first controller of the substrate processing system through a wiring. The measurement apparatus measures the flow rate of the gas output from the flow rate controller according to the instruction from the first controller. The measurement apparatus includes a second controller. The measurement apparatus includes a relay provided on the wiring. The second controller is configured to control the relay.

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.

An ultrasonic meter configured to operate in multiple classes is provided including a flowtube having an inlet at a first end and an outlet at a second end, opposite the first end; and first and second face to face transducers, the first transducer being positioned at the first end of the flowtube and the second transducer being positioned at the second end of the flowtube, wherein the first and second face to face transducers are positioned in line with flow through the ultrasonic meter. Related flowtubes are also provided herein.

The present invention is in the field of end of the line testers. More specifically, the present invention is a preconditioned air tester

A gas meter with a rated maximum flow capacity of greater than 3,000 CFH (Cubic Feet per Hour)for example, between 3,500 CFH and 7,000 CFHis provided with 2-inch flange connectors. One or more undercuts are provided in the meter body to promote satisfactory performance in terms of, for example, differential pressures at the meter inlet and outlet.

A system and method for monitoring and recording methane emissions from a source of methane. In some aspects, apparatus and methods are provided for converting the emitted methane to a different compound such as carbon dioxide.

A fluid control arrangement for a medical device. The fluid control arrangement has a fluid control circuit with at least one fluid control component, through which a fluid flows. For controlling the at least one fluid control component, a control circuitry with at least one electric and/or electronic component is provided. A first carrier part has a first coupling surface and a second carrier part has a second coupling surface. In the first coupling surface at least one first fluid channel cavity and/or in the second coupling surface at least one second fluid channel cavity is provided. By connecting the carrier parts with each other with facing coupling surfaces, at least one main fluid channel is formed in the area of the separating location. At the first carrier part a first mounting surface for the at least one fluid control component can be provided.

In one embodiment, a system for controlling the delivery of process gas has a first mass flow device and a pressure transducer. The first mass flow device has a substrate block with an inlet conduit and an outlet conduit. A proportional valve having a first valve body is mounted to the substrate block and fluidly connected to the inlet conduit. A characterized restrictor is fluidly connected to the proportional valve and the outlet conduit.

A mass flow control apparatus having a monolithic base. The monolithic base has a gas inlet, a gas outlet, a first flow component mounting region, a second flow component mounting region, and a third flow component mounting region. The first flow component mounting region has a first inlet port and a first outlet port, the first inlet port being fluidly coupled to the gas inlet of the monolithic base. The second flow component mounting region has a second inlet port, a second outlet port, and a first auxiliary port.