Patent application number | Description | Published |
20090183548 | METHOD AND APPARATUS FOR IN SITU TESTING OF GAS FLOW CONTROLLERS - Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test. | 07-23-2009 |
20090183549 | METHOD AND APPARATUS FOR IN SITU TESTING OF GAS FLOW CONTROLLERS - Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test. | 07-23-2009 |
20110011183 | METHOD AND APPARATUS FOR IN SITU TESTING OF GAS FLOW CONTROLLERS - Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test. | 01-20-2011 |
20110108126 | METHOD AND APPARATUS FOR GAS FLOW CONTROL - A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow. | 05-12-2011 |
20120132291 | TRANSIENT MEASUREMENTS OF MASS FLOW CONTROLLERS - An apparatus to measure the transient response of a mass flow controller (MFC). The size of a variable orifice, upstream of the MFC, is controlled such that the pressure between the orifice and the MFC is held constant during the entire time that the MFC is going through its transient response. The known relationship between the size of the orifice and the flow through it allows a determination of the transient response of the MFC. | 05-31-2012 |
20120304781 | METHOD AND APPARATUS FOR IN SITU TESTING OF GAS FLOW CONTROLLERS - Methods and apparatus utilize a rate of drop in pressure upstream of a gas flow controller (GFC) to accurately measure a rate of flow through the GFC. Measurement of the gas flow through the many gas flow controllers in production use today is enabled, without requiring any special or sophisticated pressure regulators or other special components. Various provisions ensure that none of the changes in pressure that occur during or after the measurement perturb the constant flow of gas through the GFC under test. A pressure regulator is coupled to a gas source. The GFC is positioned downstream of the pressure regulator. A pressure transducer is measuring pressure in a volume between the pressure regulator and the GFC, wherein means are provided for increasing the pressure in the volume. | 12-06-2012 |
20140366952 | METHOD AND APPARATUS FOR GAS FLOW CONTROL - A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow. | 12-18-2014 |
20140367596 | METHOD AND APPARATUS FOR GAS FLOW CONTROL - A method and apparatus for self-calibrating control of gas flow. The gas flow rate is initially set by controlling, to a high degree of precision, the amount of opening of a flow restriction, where the design of the apparatus containing the flow restriction lends itself to achieving high precision. The gas flow rate is then measured by a pressure rate-of-drop upstream of the flow restriction, and the amount of flow restriction opening is adjusted, if need be, to obtain exactly the desired flow. | 12-18-2014 |