Title:
MASS FLOW RATE MEASURING METHOD AND MASS FLOW RATE CONTROLLER
Document Type and Number:
Japanese Patent JP3604354
Kind Code:
B
Abstract:
PROBLEM TO BE SOLVED: To accurately and efficiently calculate the true mass flow rate of various gas species according to a micro mass flow control technology using ultrasonic nozzles.
SOLUTION: Many kinds of gas species are classified into e.g. five groups A-D and typical effluence coefficients Cda-Cde are predetermined for the groups. The upstream pressure and temperature of an ultrasonic nozzle are detected for a gas to calculate a theoretical mass flow rate Qth. In this calculation of the flow rate Qth, a theoretical mass flow rate vs. effluence coefficient table 52 stored in a memory is referred, corresponding to the gas groups A-E, to select a desired effluence coefficient CD (among Cda-Cde). In selection of the coefficient Cd, the true mass flow rate Qtr is obtained according to Qtr= Cd×Qth. Owing to such gas classification, the true mass flow rate Qtr can be measured with a little memory capacity, even if the kind of gas differs or increases.
More Like This:
| JP56160660 | PITOT TUBE FOR MEASURING AVERAGE WIND SPEED |
| WO/2009/045838 | FILTER MONITOR-FLOW METER COMBINATION SENSOR |
| JP57144421 | FLOW RATE MEASURING DEVICE FOR STEAM |
Inventors:
Horiuchi, Tatsu
Shinozaki, Kenji
Shinozaki, Kenji
Application Number:
JP2001000178430
Publication Date:
October 08, 2004
Filing Date:
June 13, 2001
Export Citation:
Assignee:
SMC CORP
International Classes:
G01F1/34; G01F1/00; G01F1/42; G01F1/50; G01F15/04; G01F25/00; G05D7/06; G01F1/34; G01F1/00; G01F15/00; G01F25/00; G05D7/06; (IPC1-7): G01F1/34; G01F1/00; G01F1/50; G01F25/00