Abstract: A method of preventing a mass flow controller from participating in crosstalk in an array of mass flow controllers is described. The method includes sensing and providing a signal indicative of a fluid pressure inside of a mass flow controller with a pressure sensor contained within the mass flow controller, determining a response of a control valve to a rapid pressure perturbation at the inlet of the mass flow controller using the signal indicative of the fluid pressure to avoid overcompensation for the rapid pressure perturbation, and adjusting a control valve contained within the mass flow controller downstream of the pressure sensor, based on the determined response, so that the mass flow controller avoids overcompensating for the rapid pressure perturbation. The pressure sensor is positioned such that the pressure sensor is sensitive to rapid pressure perturbations at the inlet of the mass flow controller.

Abstract: A method of preventing a mass flow controller from participating in crosstalk in an array of mass flow controllers is described. The method includes sensing and providing a signal indicative of a fluid pressure inside of a mass flow controller with a pressure sensor contained within the mass flow controller, determining a response of a control valve to a rapid pressure perturbation at the inlet of the mass flow controller using the signal indicative of the fluid pressure to avoid overcompensation for the rapid pressure perturbation, and adjusting a control valve contained within the mass flow controller downstream of the pressure sensor, based on the determined response, so that the mass flow controller avoids overcompensating for the rapid pressure perturbation. The pressure sensor is positioned such that the pressure sensor is sensitive to rapid pressure perturbations at the inlet of the mass flow controller.

Abstract: A method of preventing a mass flow controller from participating in crosstalk in an array of mass flow controllers is described. The method includes sensing and providing a signal indicative of a fluid pressure inside of a mass flow controller with a pressure sensor contained within the mass flow controller, determining a response of a control valve to a rapid pressure perturbation at the inlet of the mass flow controller using the signal indicative of the fluid pressure to avoid overcompensation for the rapid pressure perturbation, and adjusting a control valve contained within the mass flow controller downstream of the pressure sensor, based on the determined response, so that the mass flow controller avoids overcompensating for the rapid pressure perturbation. The pressure sensor is positioned such that the pressure sensor is sensitive to rapid pressure perturbations at the inlet of the mass flow controller.

Abstract: A method of preventing a mass flow controller from participating in crosstalk in an array of mass flow controllers is described. The method includes sensing and providing a signal indicative of a fluid pressure inside of a mass flow controller with a pressure sensor contained within the mass flow controller, determining a response of a control valve to a rapid pressure perturbation at the inlet of the mass flow controller using the signal indicative of the fluid pressure to avoid overcompensation for the rapid pressure perturbation, and adjusting a control valve contained within the mass flow controller downstream of the pressure sensor, based on the determined response, so that the mass flow controller avoids overcompensating for the rapid pressure perturbation. The pressure sensor is positioned such that the pressure sensor is sensitive to rapid pressure perturbations at the inlet of the mass flow controller.

Abstract: A combination manual/pneumatic shut-off valve (11) is disclosed. The valve comprises a housing (13); a valve chamber (17) which is disposed in the housing and which has a fluid inlet (19) and a fluid outlet (21); a diaphragm (23); a valve seat (25); a pneumatically driven actuator (29) which is adapted to move the diaphragm from a first position in which the diaphragm and the valve seat form a seal between the fluid inlet and the fluid outlet, to a second position in which the fluid inlet and fluid outlet are in open communication with each other; and a handle (31) adapted to manually move the diaphragm from the second position to the first position by way of the actuator, independently of the pneumatic control signal. The valve allows the length of process fluid control assemblies, and hence the size of fluid panels, to be reduced by combining the functionalities of a manual valve and a pneumatic valve into a single element.