A fluid delivery system includes N first valves. Inlets of the N first valves are fluidly connected to N gas sources, respectively, where N is an integer greater than zero. N mass flow controllers include a microelectromechanical (MEMS) Coriolis flow sensor having an inlet in fluid communication with an outlet of a corresponding one of the N first valves. A second valve has an inlet in fluid communication with an outlet of the MEMS Coriolis flow sensor and an outlet supplying fluid to treat a substrate arranged in a processing chamber. A controller in communication with the MEMS Coriolis flow sensor is configured to determine at least one of a mass flow rate and a density of fluid flowing through the MEMS Coriolis flow sensor.

Mass flow meters and mass flow controllers that include mass flow meters are disclosed. A mass flow meter includes a main flow path for a gas, and a bypass with a length, L, within the main flow path. The bypass includes a continuous flow section including a plurality of continuous capillary tubes that each have a length, L. The bypass also includes n flow segments forming n1 spaces within the bypass where n is greater than or equal to 2, and each of the flow segments has a plurality of capillary tubes. The mass flow meter also includes at least one thermal sensor including a sensor tube, and the sensor tube is positioned across at least one of the flow segments to divert a portion of the gas around the at least one of the flow segments and provide a measured flow signal in response to the diverted portion of the gas.

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.

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.

A gas-detecting apparatus includes a pump module connected to a first input and a second input to intake air, a sensor module including at least one unit sensor configured to output a sensing signal in response to gas present in the air, and a control module configured to detect the gas using the sensing signal. The control module controls the pump module to intake second air by opening the second input when gas is detected in first air introduced through the first input, and determines that gas is detected when a concentration of gas detected in the second air is lower than a concentration of gas detected in the first air.

A gas-detecting apparatus includes a pump module connected to a first input and a second input to intake air, a sensor module including at least one unit sensor configured to output a sensing signal in response to gas present in the air, and a control module configured to detect the gas using the sensing signal. The control module controls the pump module to intake second air by opening the second input when gas is detected in first air introduced through the first input, and determines that gas is detected when a concentration of gas detected in the second air is lower than a concentration of gas detected in the first air.

A polymer is flowed through a slim tube including porous media until steady state is achieved. A temperature of the porous media with the polymer is adjusted to emulate a reservoir temperature. A slug of a gel solution is flowed through the porous media in the slim tube. The gel solution includes the polymer and a crosslinker. The gel solution is configured to at least partially solidify at the temperature. Multiple pressure drops across the porous media in the slim tube are measured at corresponding locations along a length of the slim tube while the slug flows through the porous media in the slim tube. The slug at least partially solidifies within the slim tube, causing an increase in pressure. A location of gelation of the slug of gel solution within the slim tube is determined based on the increase in pressure.

A polymer is flowed through a slim tube including porous media until steady state is achieved. A temperature of the porous media with the polymer is adjusted to emulate a reservoir temperature. A slug of a gel solution is flowed through the porous media in the slim tube. The gel solution includes the polymer and a crosslinker. The gel solution is configured to at least partially solidify at the temperature. Multiple pressure drops across the porous media in the slim tube are measured at corresponding locations along a length of the slim tube while the slug flows through the porous media in the slim tube. The slug at least partially solidifies within the slim tube, causing an increase in pressure. A location of gelation of the slug of gel solution within the slim tube is determined based on the increase in pressure.

Mass flow meters and mass flow controllers that include mass flow meters are disclosed. A mass flow meter includes a main flow path for a gas, and a bypass with a length, L, within the main flow path. The bypass includes a continuous flow section including a plurality of continuous capillary tubes that each have a length, L. The bypass also includes n flow segments forming n1 spaces within the bypass where n is greater than or equal to 2, and each of the flow segments has a plurality of capillary tubes. The mass flow meter also includes at least one thermal sensor including a sensor tube, and the sensor tube is positioned across at least one of the flow segments to divert a portion of the gas around the at least one of the flow segments and provide a measured flow signal in response to the diverted portion of the gas.

A polymer is flowed through a slim tube including porous media until steady state is achieved. A temperature of the porous media with the polymer is adjusted to emulate a reservoir temperature. A slug of a gel solution is flowed through the porous media in the slim tube. The gel solution includes the polymer and a crosslinker. The gel solution is configured to at least partially solidify at the temperature. Multiple pressure drops across the porous media in the slim tube are measured at corresponding locations along a length of the slim tube while the slug flows through the porous media in the slim tube. The slug at least partially solidifies within the slim tube, causing an increase in pressure. A location of gelation of the slug of gel solution within the slim tube is determined based on the increase in pressure.