Abstract: A method of characterizing hysteresis as a function of a device output comprising, applying an input signal across a first input signal range to a device, the input signal inducing a device function having a first output with a first output value range dependent upon the first input signal range. The input signal is further applied across a second input signal range to the device, the input signal inducing the device function to have a second output with a second output value range dependent upon (i) the second input signal range and (ii) device hysteresis. A difference between the second input signal range and the first input signal range is then measured across the first and second output value ranges. A method of operating a mass flow controller valve and a mass flow controller are also contemplated.

Abstract: A mass flow controller among other embodiments and method is described. The mass flow controller including a thermal mass flow sensor including at least two sensing elements coupled to a sensor tube of the mass flow controller, the thermal mass flow sensor being designed to provide a first signal indicative of flow of a gas within a first flow-rate-range and a second signal indicative of flow of the gas within a second flow-rate-range; and a control portion figured to control a valve position of the mass flow controller responsive to the first signal when the flow of the gas is within the first flow-rate-range and control the valve position of the mass flow controller responsive to the second signal when the flow of the gas is within a second flow-rate-range.

Abstract: A mass flow controller (MFC), a method for calibrating an MFC, and a method for operating an MFC are disclosed. The method for calibrating the MFC includes obtaining data relative to two signals from a thermal mass flow sensor when operating the mass flow controller at different flow rates with a calibration gas, and storing the data relating to the two signals in connection with corresponding flow-rate values. The method for operating the MFC includes obtaining data relative to the two signals from the thermal mass flow controller and accessing the calibration data to determine an unknown flow rate for a process gas that may be the same gas as the calibration gas or may be another gas that is different from the calibration gas.

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: 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: One method of obtaining an initial adjusted mass flow controller valve start position comprises obtaining a mass flow controller delay period and setting a mass flow controller valve to an initial valve opening position that is less than an expected optimal valve opening position. An initial desired flow rate and initial operating conditions are input into a control system that is in communication with the valve, and the control system is initiated. The control system is adapted to adjust the valve opening position to achieve the initial desired flow rate, while taking into account flow rate and valve position feedback to the control system. During operation of the MFC and control system, the valve position and the flow rate are recorded in one embodiment and a flow rate that one of meets and exceeds a threshold is detected.

Abstract: A temperature insensitive mass flow controller comprising a main flow line, a capillary tube coupled to the main flow line across a bypass a thermal sensing element coupled to the capillary tube and a mass flow controller housing adapted to at least cover the capillary tube. A first heat sink has been coupled to the mass flow controller internal to the mass flow controller housing and coupled to the capillary tube. The heat sink being adapted to control a temperature of a gas in the capillary tube.

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: One embodiment of the present invention comprises a thermal flow sensor having a first capillary tube coupled to a mass flow controller main flow line across a mass flow controller bypass. A first pair of sensing elements is coupled to the first capillary tube. The thermal sensor also comprise a second capillary tube having a substantially similar cross-sectional area to the first capillary tube, a first end thermally coupled to one of a mass flow controller base and the first tube proximal the first tube inlet port, and a second end thermally coupled to one of the mass flow controller base and the first tube proximal the outlet port. The second tube is not adapted to receive and eject a fluid flow. A second pair of sensing elements is coupled to the second tube.

Abstract: One embodiment of the invention comprises a mass flow controller comprising a digital controller, a valve, and a sensor. The digital controller is adapted to implement a control loop having a proportional signal modifier in series with an integral signal modifier. The integral signal modifier is adapted to receive a combination signal and output an integrated signal. The valve is adapted to receive the integrated signal and adjust a valve opening in accordance with the integrated signal. The sensor is adapted to output a measured flow rate signal indicative of an actual fluid flow rate in the mass flow controller. The measured flow rate signal is received by the proportional signal modifier and used in conjunction with a setpoint signal to determine the error signal.

Abstract: One embodiment of the present invention comprises a mass flow controller. The mass flow controller may comprise a pair of thermal sensing elements, a bridge circuit adapted to receive at least one first signal from the pair of thermal sensing elements and a differential amplifier adapted to (i) receive at least one bridge signal from the bridge circuit, and (ii) emit an output signal generally proportional to a flow rate of fluid passing through the mass flow controller. The mass flow controller is also comprised in one embodiment of a filter portion of a control module having one or more first filters comprising substantially permanent parameters adapted to provide a more accurate output signal for a baseline fluid upon a change in the flow rate and one or more second filters comprising variable parameters, with each of the one or more second filters being adapted to provide a more accurate output signal for non-baseline fluids upon a change in the flow rate.

Abstract: One embodiment comprises a method of providing accurate mass flow controller flow rate data for a non-manufacturing-tuning-gas. The mass flow controller may be operated at a setpoint greater than 50%. Data may be recorded to a mass flow controller memory. The setpoint may then be changed to 0%. The recorded data may then be analyzed and one or more non-manufacturing-tuning-gas correction algorithm parameters may be calculated. The one or more non-manufacturing-tuning-gas correction algorithm parameters may be stored in a mass flow controller memory and subsequently used in at least one future mass flow controller operation involving the non-manufacturing-tuning-gas.

Abstract: One embodiment comprises a method of providing accurate mass flow controller flow rate data for a non-manufacturing-tuning-gas. The mass flow controller may be operated at a setpoint greater than 50%. Data may be recorded to a mass flow controller memory. The setpoint may then be changed to 0%. The recorded data may then be analyzed and one or more non-manufacturing-tuning-gas correction algorithm parameters may be calculated. The one or more non-manufacturing-tuning-gas correction algorithm parameters may be stored in a mass flow controller memory and subsequently used in at least one future mass flow controller operation involving the non-manufacturing-tuning-gas.

Abstract: One method of obtaining an initial adjusted mass flow controller valve start position comprises obtaining a mass flow controller delay period and setting a mass flow controller valve to an initial valve opening position that is less than an expected optimal valve opening position. An initial desired flow rate and initial operating conditions are input into a control system that is in communication with the valve, and the control system is initiated. The control system is adapted to adjust the valve opening position to achieve the initial desired flow rate, while taking into account flow rate and valve position feedback to the control system. During operation of the MFC and control system, the valve position and the flow rate are recorded in one embodiment and a flow rate that one of meets and exceeds a threshold is detected.

Abstract: A mass flow controller among other embodiments and method is described. The mass flow controller including a thermal mass flow sensor including at least two sensing elements coupled to a sensor tube of the mass flow controller, the thermal mass flow sensor being designed to provide a first signal indicative of flow of a gas within a first flow-rate-range and a second signal indicative of flow of the gas within a second flow-rate-range; and a control portion figured to control a valve position of the mass flow controller responsive to the first signal when the flow of the gas is within the first flow-rate-range and control the valve position of the mass flow controller responsive to the second signal when the flow of the gas is within a second flow-rate-range.

Abstract: A mass flow controller (MFC), a method for calibrating an MFC, and a method for operating an MFC are disclosed. The method for calibrating the MFC includes obtaining data relative to two signals from a thermal mass flow sensor when operating the mass flow controller at different flow rates with a calibration gas, and storing the data relating to the two signals in connection with corresponding flow-rate values. The method for operating the MFC includes obtaining data relative to the two signals from the thermal mass flow controller and accessing the calibration data to determine an unknown flow rate for a process gas that may be the same gas as the calibration gas or may be another gas that is different from the calibration gas.

Abstract: One embodiment of the present invention involves a thermal sensor and a method of using the same. One thermal sensor is adapted to output a signal which is unaffected by external longitudinal and orthogonal thermal gradients. In one embodiment, the mass flow controller thermal sensor comprises a capillary tube having an upstream tube portion, a tube bend portion, and a downstream tube portion, the downstream portion being substantially parallel to the upstream portion. A distance between the upstream tube portion and the downstream tube portion in one embodiment is no greater than half the upstream portion and downstream portion lengths, a first pair of thermal sensing elements are coupled to the upstream tube portion and a second pair of thermal sensing elements are coupled to the downstream tube portion.

Abstract: A system and method for delivering a specified-quantity of a fluid using a flow controller based on a fluid delivery profile is described. One embodiment includes a fluid delivery profile that includes a delivery time window with a plurality of set points that each correspond with a specified instant in time within the delivery time window. The method also includes delivering the fluid according to the fluid delivery profile through a variable valve using the flow controller and a feedback signal from a flow sensor.

Abstract: A temperature insensitive mass flow controller comprising a main flow line, a capillary tube coupled to the main flow line across a bypass a thermal sensing element coupled to the capillary tube and a mass flow controller housing adapted to at least cover the capillary tube. A first heat sink has been coupled to the mass flow controller internal to the mass flow controller housing and coupled to the capillary tube. The heat sink being adapted to control a temperature of a gas in the capillary tube.