Patent ID: 6240776
Filing Date: 2001-06-05
Classification: G01F

Abstract:
An improved mass flow sensing apparatus adapted for fast temperature sensing responses, comprising:a flow chamber for housing incoming fluid and outgoing fluid;an incoming flow tube for receiving incoming fluid from said flow chamber;an outgoing flow tube for providing outgoing fluid to said flow chamber;a short sensing tube coupled between said incoming flow tube and said outgoing flow tube for holding a low mass portion of the incoming fluid;a short, flow bypass element for receiving a portion of the incoming fluid to bypass said sensing tube; anda pair of inductive heating and sensing coils wrapped around said sensing tube for heating the low mass portion of the incoming fluid in said sensing tube to maintain a constant temperature for said low mass portion, the mass flow rate of the fluid being derived from power necessary to maintain a constant temperature of said low mass portion of fluid in said sensing tube.