Patent ID: 6640650
Filing Date: 2003-11-04
Classification: G01F

Abstract:
A flow rate sensor comprising a chamber with first and second diaphragms arranged therein, in an opposed relation to each other,wherein said chamber is divided into a primary chamber facing said first diaphragm and a secondary chamber facing said second diaphragm, wherein a fluid is passed from said primary chamber to said secondary chamber through a bypass having an orifice member thereby to generate a differential pressure between said primary chamber and said secondary chamber, wherein the load difference generated by the fluid pressure fluctuations received by said first diaphragm and said second diaphragm is detected as a displacement by a load difference sensor arranged between said first diaphragm and said second diaphragm thereby to detect the flow rate of said fluid, and wherein a selected one of said diaphragm pair and said load difference sensor includes at least a displacement limiting member for preventing the displacement generated by the fluid pressure fluctuations received by said diaphragms from increasing beyond a predetermined amount.