Abstract: A flow sensor which includes a support structure including a base having a plurality of spaced mesas on a surface thereof is provided. A low thermal conductivity, dielectric diaphragm spanning the mesas is supported along its length thereby and forms an electrical and thermal insulation barrier over the support structure and the mesas. At least one flow sensing element is superposed on the diaphragm so that the flow sensing element is substantially electrically and thermally isolated from the support structure. A method for fabricating the flow sensor is also provided.

Abstract: A mass airflow meter for positioning within a duct wherein a fluid flows, particularly an air intake of an internal combustion engine, includes a symmetrical body having an axial passageway and a radial passageway. The radial passageway has a temperature dependent element positioned therein and extends from the axial passageway at an acute angle to the downstream flow of air. Accordingly, the radial passageway provides inertial separation of airborne particulate and also provides isolation from air flowing backwards through the air intake.

Abstract: A device for measuring the velocity of fluid includes a vortex generating means positioned in the fluid stream so that vortices are formed in the wake of the generating means. Plates elongated in the direction of fluid flow are positioned adjacent the vortex generating means to improve detection of the vortices by increasing the signal to noise ratio.

Abstract: A heated element mass air flow meter 10 includes a cylinder 20 having a surface 21 with an area of stagnation 22. Element 11 is positioned aft of area of stagnation 22 and forward of a downstream area of turbulence 23. Deposition of air born dirt takes place at the stagnation area because dirt particles have a greater density and inertia than air and cannot turn as easily. The air passing the element has been substantially separated from air born dirt and carries less dirt than the remainder of the air stream. The accuracy of heated element meters is reduced by deposition of dirt on the element. A configuration as described reduces the amount of dirt striking the heated element 11 and improves accuracy of the meter.

Abstract: A vortex generator of triangular cross section has ridges on the upstream surfaces. Ridges which extend longitudinally in a direction parallel to the flow are located on the wall.

Abstract: A device for measuring the velocity of fluid includes a vortex generating means, a pressure sensor means and a processing means. The vortex generating means is positioned in the fluid stream so that vortices are formed in the wake of the generating means. The pressure sensor means is positioned in the wake of the generating means for sensing pressure variation caused by the passage of the vortices. The processing means is coupled to the pressure sensor for determining the fluid flow rate as a function of pressure changes sensed by the pressure sensor means.