Fluid flow meter head and system using same

Claim 2

An airflow meter head for fluid connection to a means for measuring differential fluid pressure to provide an indication of the velocity pressure for measuring fluid flow rate, comprising: a single hollow tubular member aving a wall dividing the hollow into two separate chambers, said member having a series of axially spaced openings from a first of said chambers through the member to open facing forwardly and having one or more openings from the second of said chambers through the member to open facing other than forwardly, the sum of the crosssectional areas of each series of openings being less than the cross-sectIonal area of the chamber associated therewith, said tubular member being provided with a spaced pair of rearwardly extending walls for creating a low pressure area therebetween when the tubular member is located in the path of fluid flow; means mounting the member in the path of fluid flow, with the forwardly facing openings facing the flow of fluid to provide a total pressure sensing chamber, and with the other openings facing other than towards the flow of fluid to provide a low pressure sensing chamber; and means fluidly connecting each of said chambers to the measuring means.

Claim 3

The air flow meter head as in claim 1 wherein the openings facing other than forwardly, face rearwardly and open into the space between the rearwardly extending walls.

Claim 4

An airflow meter head for fluid connection to a means for measuring differential fluid pressure to provide an indication of the velocity pressure for measuring fluid flow rate, comprising: a single hollow tubular member having a wall dividing the hollow into two separate chambers, said member having a series of axially spaced openings from a first of said chambers through the member to open facing forwardly and having a series of axially spaced openings from the second of said chambers through the member to open facing other than forwardly, the sum of the cross-sectional areas of each series of openings being less than the cross-sectional area of the chamber associated therewith, said openings facing other than forwardly being provided in two sets, one set of openings facing rearwardly and the other set of openings facing other than forwardly and rearwardly, means provided in the second chamber for selectively opening one set to the chamber while closing the other set to the chamber; means mounting the member in the path of fluid flow, with the forwardly facing openings facing the flow of fluid to provide a total pressure sensing chamber, and with the other openings facing other than towards the flow of fluid to provide a low pressure sensing chamber; and means fluidly connecting each of said chambers to the measuring means.

Claim 5

An airflow meter head for fluid connection to a means for measuring differential fluid pressure to provide an indication of the velocity pressure for measuring fluid flow rate, comprising: a single hollow tubular member having a wall dividing the hollow into two separate chambers, said member having a series of axially spaced openings from a first of said chambers through the member to open facing forwardly and having a series of axially spaced openings from the second of said chambers through the member to open facing other than forwardly, the sum of the cross-sectional areas of each series of openings being less than the cross-sectional area of the chamber associated therewith, said openings facing other than forwardly being provided in two sets, one set of openings facing rearwardly and the other set of openings facing other than forwardly and rearwardly, means provided in the second chamber for selectively opening one set to the chamber while closing the other set to the chamber; means mounting the member in the path of fluid flow, with the forwardly facing openings facing the flow of fluid to provide a total pressure sensing chamber, and with the other openings facing other than towards the flow of fluid to provide a low pressure sensing chamber; and means fluidly connecting each of said chambers to the measuring means.

Claim 6

The air flow meter head as in claim 3 wherein the selecting means includes a generally U-shaped blocking member for insertion into the second chamber, said blocking member having cutouts therein which are aligned with the one set.

Claim 7

The air flow meter head as in claim 3 wherein the second chamber has oppositely opening, member-receiving, longitudinal grooves cut therein, wherein both sets of openings open into this groove, and wherein the selecting means includes slidable selecting members slidably located in these grooves, said selecting members having cutouts which may be aligned with either set of openings and includes moving means for sliding the selecting members to align the cutouts thereof with the desired set of openings.

Claim 8

The air flow meter head as in claim 5 wherein the slidable selecting member includes: an elongated member located in each groove,and round springs between the elongated members for biasing the elongated members into the grooves.

Claim 9

The air flow meter head as in claim 5 wherein the sets of openings are axially spaced and alternating, and wherein the selecting members have alternating cutout portions and solid portions, sliding of the selecting members moving the cutout portions from alignment with one set to alignment with the other set while moving the solid portions from alignment with the other set to alignment with the one set.