Gas flow calibration of mass flow controllers

Patent 6332348 Issued on December 25, 2001. Estimated Expiration Date:

January 5, 2020. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

3148527

3330156

Flowmeter calibration method
Patent #: 5648605
Issued on: 07/15/1997
Inventor: Takahashi

Apparatus to check calibration of mass flow controllers Patent #: 5744695
Issued on: 04/28/1998
Inventor: Forbes

Inventors

Assignee

Advanced Micro Devices, Inc.

Application

No. 478154 filed on 01/05/2000

US Classes:

73/1.34With signal processing, span or set point adjustment (e.g., zero correction)

Examiners

Primary: Williams, Hezron
Assistant: Politzer, Jay L.

Attorney, Agent or Firm

International Class

G01F 025/00

Abstract

A method, system, and storage medium for gas flow calibration of mass flow controllers (MFCs) is presented. A second mass flow controller that has a full scale range substantially less than that of a mass flow meter (MFM) may be calibrated by the MFM using a "gas biasing" technique. A first MFC is set such that a first flow of gas through the MFM at a first flow rate results. The first flow rate is preferably approximately 50% of the full scale range of the MFM. A first reading of the MFM is then recorded. The second MFC is then set such that a second gas flow of gas through the MFM at a second flow rate results. A second reading of the MFM is then recorded. The difference between the second and first readings is then compared to the set flow rate of the second MFC to determine the calibration of the second MFC. The full scale range of the second MFC may be less than 1% of the full scale range of the MFM.