Gas Flow Validation Using Precision Orifice and Choked Flow

The patent extracts the flow verification measurement from the large reaction chamber to a small external chamber or flow measurement standard. This separation allows rapid measurements to be performed outside the production chamber, eliminating the time penalty from chamber cooling and setup while maintaining measurement accuracy through standardized measurement conditions.

The patent introduces an intermediary flow measurement standard or external chamber that acts as a mediator between the MFC and the reaction chamber. This intermediary device provides a controlled environment for accurate flow measurements without requiring the reaction chamber to be taken offline, thus reducing verification time while maintaining precision.

The patent applies parameter changes by introducing compressibility correction factors that adjust the flow measurements based on the specific gas being tested. By modifying the measurement parameters to account for gas-specific properties such as compressibility, the system maintains high verification speed while becoming adaptable to various gas types including reactive gases used in actual production.

The patent enhances the universality of the external flow measurement device by incorporating correction capabilities for different gas properties. The measurement system is designed to handle both inert calibration gases and reactive process gases by applying appropriate correction factors, making the device versatile for all gas types while maintaining rapid verification capability.

The patent implements feedback by using the external flow measurement standard to continuously verify and correct MFC performance. The system establishes a feedback loop where actual flow measurements are compared against MFC readings, and correction factors are applied to ensure accuracy translates from laboratory calibration to production environment operation.

The patent applies preliminary action by performing flow verification measurements in advance using the external standard before production runs. This preliminary verification establishes accurate baseline data and correction factors that can be applied during production, ensuring reliability without requiring repeated laboratory-style verifications that introduce conversion errors.

The patent segments the verification function from the reaction chamber by using a separate external flow measurement standard or small external chamber. This segmentation allows the verification function to be performed independently without affecting the reaction chamber schedule, eliminating cooling time requirements while maintaining comprehensive validation through separate but correlated measurements.

The patent creates a simplified copy of the flow measurement function using an external chamber or flow standard that replicates the essential measurement capability without the complexity and thermal mass of the full reaction chamber. This copy provides sufficient validation data without requiring chamber cooling, thus maintaining reliability while reducing time loss.