Patent ID: 6044701
Filing Date: 2000-04-04
Classification: G01F,G05D

Abstract:
A thermal mass flow meter for measuring a mass flow rate of a fluid, comprising:a base for receiving a flow of fluid, said base having a base inlet for receiving the flow of fluid, said base having a sensor receiving wall, said base having a primary fluid flow path defined therein and being in communication with the base inlet for carrying the flow of fluid, said base having a pressure dropping bypass positioned in the primary fluid flow path and defining an inlet side of the primary fluid flow path and an outlet side of the primary fluid flow path, the primary fluid flow path through the pressure dropping bypass being oriented to allow flow therethrough to be substantially in the direction from the inlet side to the outlet side, said base having a base outlet in communication with the outlet side of the primary fluid flow path for receiving the flow of fluid;a flow sensor measuring portion oriented substantially transversely with respect to the primary fluid flow path of said base and substantially parallel to said sensor receiving wall of said base, said flow sensor measuring portion being in communication with the primary fluid flow path via a sensor inlet for receiving a sensor portion of the flow of fluid, said flow sensor measuring portion having a flow sensor inlet and a flow sensor outlet, the flow sensor inlet and outlet being aligned in substantially the same direction as the flow path through the pressure dropping bypass;a temperature responsive element in thermal communication with said sensor flow measuring portion for producing a flow signal in response thereto; anda sensor outlet in communication with said flow sensor measuring portion for receiving the flow sensor portion of the flow of fluid from said flow sensor measuring portion, said sensor outlet being in communication with the outlet portion of the primary fluid flow path of said base.