The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 08, 1987
Filed:
Aug. 15, 1985
Harry E Aine, Los Altos, CA (US);
Other;
Abstract
An immersion-type thermal fluid flow sensor is disclosed in which the temperature dependent sensing resistor means is carried from a flexible ribbon-shaped septum immersed in the flow and arranged in a spiral, meander or other geometrical configuration to partition the total flow passageway into a plurality of parallel flow portions. In one embodiment, the partitioned flow passageways are dimensioned to have a length to cross-sectional dimension ratio for providing laminar flow conditions over the operating flow range of interest. In another embodiment, a heater is provided for heating the septum to a temperature near that of the sensing resistor to reduce the time constant of the flow measurement. In another embodiment, a thermal loading element is coupled in heat exchanging relation with the sensing resistors for increasing the critical flow rate and thus for increasing the operating range of the flow regime wherein the temperature difference .DELTA.T between the upstream and downstream resistors is a direct function of mass flow rate. Also, in another embodiment, thermal gradient shields shield the flow sensing resistors from external thermal gradients.