US 12,000,723 B2
Method and apparatus for pressure based mass flow control
Junhua Ding, Boxborough, MA (US)
Assigned to MKS Instruments, Inc., Andover, MA (US)
Filed by MKS Instruments, Inc., Andover, MA (US)
Filed on Feb. 18, 2022, as Appl. No. 17/651,751.
Prior Publication US 2023/0266156 A1, Aug. 24, 2023
Int. Cl. G01F 1/88 (2006.01); G01F 15/00 (2006.01); G05D 7/00 (2006.01); G05D 16/00 (2006.01)
CPC G01F 1/88 (2013.01) [G01F 15/005 (2013.01); G01F 15/002 (2013.01); G01F 15/003 (2013.01); G05D 7/00 (2013.01); G05D 16/028 (2019.01)] 24 Claims
OG exemplary drawing
 
1. A mass flow controller, comprising:
a body having a valve outlet bore defining a flow path;
an adjustable valve configured to control flow of a gas through the flow path, a valve element comprising an outlet orifice of the adjustable valve, the valve element disposed within the bore;
a pressure drop element disposed coaxially with the valve element within the bore;
an upstream pressure sensor configured to detect a pressure at a location in the flow path between the adjustable valve and the pressure drop element; and
a controller configured to determine a flow rate through the flow path based on pressure as detected by the upstream pressure sensor.