Title:
THERMAL MASS FLOW SENSOR WITH IMPROVED ACCURACY
Document Type and Number:
WIPO Patent Application WO/2019/208447
Kind Code:
A1
Abstract:
Mass flow controllers and methods for controlling mass flow controllers are disclosed. A method includes providing a gas through a thermal mass flow sensor of the mass flow controller and processing a flow sensor signal from the thermal mass flow sensor of the mass flow controller to produce a measured flow signal. The measured flow signal is corrected to produce a corrected flow signal by gradually applying nonlinearity correction to the measured flow signal when a flow rate of the gas changes. A valve of the mass flow controller is controlled using the corrected flow signal and a setpoint signal.
Inventors:
SMIRNOV ALEXEI V (US)
Application Number:
PCT/JP2019/016866
Publication Date:
October 31, 2019
Filing Date:
April 19, 2019
Export Citation:
Assignee:
HITACHI METALS LTD (JP)
International Classes:
G05D7/06
Foreign References:
| US20140246097A1 | 2014-09-04 | |||
| US20170167912A1 | 2017-06-15 | |||
| JPH0756636A | 1995-03-03 | |||
| US20050000981A1 | 2005-01-06 | |||
| US5129418A | 1992-07-14 | |||
| US6389364B1 | 2002-05-14 | |||
| JP2002082722A | 2002-03-22 |
Attorney, Agent or Firm:
KOHNO, Hideto et al. (JP)
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