Abstract: Mass flow controllers and methods for improving the control of a flow of a variety of fluid types are described. The method includes selecting a process gas type for the process gas that will be controlled and obtaining molecular mass information for the selected processed gas type. General characterization data is obtained that includes, for each of a plurality of flow and pressure value pairs, a corresponding control signal value and operating characterization data is generated by modifying the flow values in the general characterization data based upon the molecular mass for the selected process gas type. The operating characterization data is then used to operate a valve of the mass flow controller in open loop control mode.

Abstract: Mass flow controllers with on-tool diagnostic capabilities and methods for on-tool diagnosis of mass flow controllers are disclosed herein. One method includes opening a control valve to a fixed position and closing an upstream valve to produce a flow rate that decreases from a high flow rate, across a range of flow rates, to a low flow rate. A pressure signal is generated that is indicative of a pressure of the fluid within a volume between the upstream valve and a sensor tube, and a flow sensor signal is provided with the mass flow sensor that is indicative of a mass flow rate of the fluid through the main flow path. Ratio curves are produced that relate, across the range of flow rates, a rate of change of the pressure signal to the flow sensor signal and comparing a test ratio curve to a previously generated baseline ratio curve.

Abstract: A mass flow controller and method for operating the same is disclosed. The mass flow controller includes a mass flow control system to control the mass flow rate of a fluid, and a data logging component that obtains snapshots of condition-specific-data for each of a plurality of reoccurring condition types, and reduces each snapshot of condition-specific-data to functional parameter values that characterize each snapshot of condition-specific-data, and the data logging component generates statistical values that are stored in a short term data store that characterize multiple functional parameter values that are obtained during each separate occurrence of a specific condition type. A diagnostics component diagnoses failures using current functional parameter values and the statistical values stored in the short-term memory, and a prognostics component predicts failures based upon a collection of data sets that are stored in the long-term memory.

Abstract: Gas insensitive systems and methods for controlling the mass flow rate of a gas through a primary conduit are disclosed. The method includes producing, in a secondary conduit, an assessment flow that has a changing pressure; calculating a first measure of a flow rate of the assessment flow based upon a rate-of-change of the pressure of the assessment flow; and measuring the assessment flow with a mass flow meter that is affected by the composition of the gas to produce a second measure of the assessment flow. An adjustment signal is generated based upon a difference between the first measure and the second measure, and a gas-corrected flow signal is generated by adjusting a measured-flow signal of a mass flow controller with the adjustment signal. The gas-corrected flow signal is used by the mass flow controller to control a flow rate of the gas through the primary conduit.

Abstract: Mass flow controllers with on-tool diagnostic capabilities and methods for on-tool diagnosis of mass flow controllers are disclosed herein. One method includes opening a control valve to a fixed position and closing an upstream valve to produce a flow rate that decreases from a high flow rate, across a range of flow rates, to a low flow rate. A pressure signal is generated that is indicative of a pressure of the fluid within a volume between the upstream valve and a sensor tube, and a flow sensor signal is provided with the mass flow sensor that is indicative of a mass flow rate of the fluid through the main flow path. Ratio curves are produced that relate, across the range of flow rates, a rate of change of the pressure signal to the flow sensor signal and comparing a test ratio curve to a previously generated baseline ratio curve.

Abstract: Systems and method for detecting a concentration of a gas in a gas stream are disclosed. A method includes receiving a gas stream including a carrier gas and a processing gas. Bridge voltages of a mass flow sensor are used to produce a processing-gas concentration signal and a gas-stream mass flow rate signal. The gas stream is controlled so a mass flow rate of the processing gas equals a processing-gas-setpoint signal. In some variations, the processing-gas-concentration signal is produced using an upstream temperature of the gas stream and a bridge-derived temperature. In other variations, the processing-gas-concentration signal is produced using a top voltage of the mass flow sensor and the gas-stream mass flow rate signal.

Abstract: An apparatus includes a chamber configured to support a number of quasi-orthogonal resonant modes, and at least one antenna assembly, where the antenna assembly includes an antenna having a radiating element, where (i) the antenna has predominantly linear polarization of radiation defined by a polarization plane, (ii) the radiating element is disposed within the chamber such that the polarization plane is not parallel and not perpendicular to the plane containing a primary axis of the chamber and a central point of the radiating element, and (iii) each antenna is coupled to the chamber through a designated surface of the chamber and coupled to a source of microwave or radio frequency energy external to the chamber having a nominal operating frequency.

Abstract: Mass flow controllers with on-tool diagnostic capabilities and methods for on-tool diagnosis of mass flow controllers are disclosed herein. One disclosed method includes effectuating a particular modification to the heating of the one or more heating-sensing elements, and monitoring one or more outputs of the mass flow sensor to obtain present data that characterizes a present operation of the mass flow sensor in response to the particular modification to the heating. Reference data is obtained that characterizes prior operation of the mass flow sensor, and the present operation of the mass flow sensor is compared to the prior operation of the mass flow sensor to assess whether the operation of the mass flow sensor changed over time.

Abstract: An apparatus includes a chamber configured to support a number of quasi-orthogonal resonant modes, and at least one antenna assembly, where the antenna assembly includes an antenna having a radiating element, where (i) the antenna has predominantly linear polarization of radiation defined by a polarization plane, (ii) the radiating element is disposed within the chamber such that the polarization plane is not parallel and not perpendicular to the plane containing a primary axis of the chamber and a central point of the radiating element, and (iii) each antenna is coupled to the chamber through a designated surface of the chamber and coupled to a source of microwave or radio frequency energy external to the chamber having a nominal operating frequency.

Abstract: Mass flow controllers with on-tool diagnostic capabilities and methods for on-tool diagnosis of mass flow controllers are disclosed herein. One disclosed method includes providing current to two heating-sensing elements of a mass flow sensor and modifying current through at least one of the heating-sensing elements. Reference data is obtained that characterizes proper operation of the mass flow sensor, and one or more flow sensor signals from the mass flow sensor are analyzed in connection with the reference data to assess whether the mass flow sensor is operating properly.

Abstract: A mass flow controller and method for operating the same is disclosed. The mass flow controller includes a mass flow control system to control the mass flow rate of a fluid, and a data logging component that obtains snapshots of condition-specific-data for each of a plurality of reoccurring condition types, and reduces each snapshot of condition-specific-data to functional parameter values that characterize each snapshot of condition-specific-data, and the data logging component generates statistical values that are stored in a short term data store that characterize multiple functional parameter values that are obtained during each separate occurrence of a specific condition type. A diagnostics component diagnoses failures using current functional parameter values and the statistical values stored in the short-term memory, and a prognostics component predicts failures based upon a collection of data sets that are stored in the long-term memory.

Abstract: A mass flow controller and method for operating the same is disclosed. The mass flow controller includes a mass flow control system to control the mass flow rate of a fluid, and a data logging component that obtains snapshots of condition-specific-data for each of a plurality of reoccurring condition types, and reduces each snapshot of condition-specific-data to functional parameter values that characterize each snapshot of condition-specific-data, and the data logging component generates statistical values that are stored in a short term data store that characterize multiple functional parameter values that are obtained during each separate occurrence of a specific condition type. A diagnostics component diagnoses failures using current functional parameter values and the statistical values stored in the short-term memory, and a prognostics component predicts failures based upon a collection of data sets that are stored in the long-term memory.

Abstract: Mass flow controllers and methods for improving the control of a flow of a variety of fluid types are described. The method includes selecting a process gas type for the process gas that will be controlled and obtaining molecular mass information for the selected processed gas type. General characterization data is obtained that includes, for each of a plurality of flow and pressure value pairs, a corresponding control signal value and operating characterization data is generated by modifying the flow values in the general characterization data based upon the molecular mass for the selected process gas type. The operating characterization data is then used to operate a valve of the mass flow controller in open loop control mode.

Abstract: A system and method for improving the control of a flow of a variety of fluid types is described. The method includes selecting a process gas type for the process gas that will be controlled and obtaining molecular mass information for the selected processed gas type. General characterization data is obtained that includes, for each of a plurality of flow and pressure value pairs, a corresponding control signal value and operating characterization data is generated by modifying the flow values in the general characterization data according to the equation Fadj=Fcal*(Mcal/Mpr)k, wherein Fadj is an adjusted flow value Fcal is the calibrated flow value, Mpr is the molecular mass for the selected process gas type, and Mcal is a molecular mass for the calibration gas. The operating characterization data is then used to operate a valve of the mass flow controller in open loop control mode.

Abstract: Mass flow controllers with on-tool diagnostic capabilities and methods for on-tool diagnosis of mass flow controllers are disclosed herein. One disclosed method includes effectuating a particular modification to the heating of the one or more heating-sensing elements, and monitoring one or more outputs of the mass flow sensor to obtain present data that characterizes a present operation of the mass flow sensor in response to the particular modification to the heating. Reference data is obtained that characterizes prior operation of the mass flow sensor, and the present operation of the mass flow sensor is compared to the prior operation of the mass flow sensor to assess whether the operation of the mass flow sensor changed over time.

Abstract: A system and method for controlling a flow of a fluid using a multi-mode control algorithm is described. The method includes disengaging and engaging a feedback control loop that controls a valve of the mass flow controller based upon a rate of pressure change of the fluid. The method also includes calculating a valve position of the valve based on pressure measurements when the feedback control loop has been disengaged and characterization data that characterizes the mass flow controller, and determining, when the feedback control loop is first re-engaged, a difference between a measured flow rate and a flow set point. An adjustment to the characterization data is applied based upon the difference to improve an accuracy of the calculation of the valve position when the feedback control loop is disengaged again.

Abstract: A mass flow controller (MFC), a method for calibrating an MFC, and a method for operating an MFC are disclosed. The MFC may include a valve that is adjustable between a closed position and an open position to control a flow rate of a fluid responsive to a control signal, a thermal mass flow sensor that provides an indication of the flow rate of the fluid, calibration data including data that relates the control signal to the flow rate of the fluid at a plurality of fluid flow rates, and a control system that provides, based upon the calibration data and run time data, an adjustable non-zero starting control signal to the valve when the valve is closed to more quickly respond to a set point signal.

Abstract: Mass flow controllers with on-tool diagnostic capabilities and methods for on-tool diagnosis of mass flow controllers are disclosed herein. One disclosed method includes providing current to two heating-sensing elements of a mass flow sensor and modifying current through at least one of the heating-sensing elements. Reference data is obtained that characterizes proper operation of the mass flow sensor, and one or more flow sensor signals from the mass flow sensor are analyzed in connection with the reference data to assess whether the mass flow sensor is operating properly.

Abstract: A mass flow controller and associated methods for providing indicated flow from the mass flow controller are disclosed. The method may include obtaining a measured flow signal indicative of a mass flow rate of a fluid that is controlled by the mass flow controller and filtering the measured flow signal to generate indicated flow that provides a representation of the actual mass flow rate of the fluid. The indicated flow is provided to an operator of the mass flow controller, and a rate of change of the mass flow rate of the fluid is determined based upon samples of the measured flow signal. A time constant used in connection with the filtering is then adjusted based upon the rate of change of the mass flow rate.

Abstract: A system and method for improving the control of a flow of a variety of fluid types is described. The method includes selecting a process gas type for the process gas that will be controlled and obtaining molecular mass information for the selected processed gas type. General characterization data is obtained that includes, for each of a plurality of flow and pressure value pairs, a corresponding control signal value and operating characterization data is generated by modifying the flow values in the general characterization data according to the equation Fadj=Fcal*(Mcal/Mpr)k, wherein Fadj is an adjusted flow value Fcal is the calibrated flow value, Mpr is the molecular mass for the selected process gas type, and Mcal is a molecular mass for the calibration gas. The operating characterization data is then used to operate a valve of the mass flow controller in open loop control mode.