# US 9,518,853 B2 · Self-diagnosing differential pressure flow meter including a directed pressure port > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,518,853 B2 - Document ID: US9518853B2 - Status: Granted - Kind: B2 - Application number: 14/426,617 - Filed: 2013-09-05 - Published: 2015-08-06 - Granted: 2016-12-13 - Earliest claimed: 2013-09-05 - Assignees: McCrometer, Inc. - Applicants: McCrometer, Inc. - Inventors: Jared Steven Ayers; Gerald E. Davis; Clinton Paul Hobbs; Eric Dahl Mikkelsen - Web page: https://patentgrep.com/patent/US9518853B2 ## CPC - G01F 1/36: the pressure or differential pressure being created by the use of flow constriction - G01F 1/74: Devices for measuring flow of a fluid or flow of a fluent solid material in suspension in another fluid - G01F 1/88: with differential-pressure measurement to determine the volume flow - G01F 15/06: Indicating or recording devices - G01F: MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME ## Abstract An aspect provides a method of metering flow through a fluid conduit having an obstruction therein, including: placing an obstruction body within the conduit; generating at least two differential pressure measurement signals using at least three different pressure ports, said at least three different pressure ports comprising: an upstream pressure port; a downstream pressure port; and an auxiliary pressure port; wherein at least one of the upstream pressure port, the downstream pressure port, and the auxiliary pressure port is positioned at an angle between 0 and 90 degrees with respect to a conduit wall; establishing a baseline relationship between the at least two differential pressure measurement signals; and determining if the baseline relationship between the at least two differential pressure measurement signals differs by a predetermined amount. Other aspects are described and claimed. ## Claims ### Claim 1 A method of metering flow through a fluid conduit, comprising: generating at least a primary differential pressure measurement signal and an auxiliary differential pressure measurement signal using at least three different pressure ports, said at least three different pressure ports comprising: a first pressure port providing a high pressure signal; a second pressure port providing a low pressure signal, the low pressure signal provided using an obstruction body disposed within the fluid conduit; a third pressure port providing an auxiliary pressure signal from a tap in a wall of a fluid conduit that is directed towards the obstruction body; and providing meter electronics that: obtain a baseline relationship between the primary differential pressure measurement signal and the auxiliary differential pressure measurement signal; and determine, at a later time, a second baseline relationship between the primary differential pressure measurement signal and the auxiliary differential pressure measurement signal. ### Claim 2 (depends on 1) The method of metering flow through a fluid conduit of claim 1, further comprising the step of comparing the baseline relationship to the second baseline relationship. ### Claim 3 (depends on 2) The method of metering flow through a fluid conduit of claim 2, further comprising the step of providing an indication in response to the baseline relationship and the second baseline relationship differing by a predetermined amount. ### Claim 4 (depends on 3) The method of metering flow through a fluid conduit of claim 3, further comprising the step of generating an alarm in response to the baseline relationship and the second baseline relationship differing by the predetermined amount. ### Claim 5 (depends on 1) The method of claim 1, wherein the third pressure port is directed between the first pressure port providing a high pressure signal and the second pressure port providing a low pressure signal. ### Claim 6 A flow metering apparatus for a fluid conduit, comprising: a fluid conduit having an obstruction body therein; a pressure port providing a high pressure signal; a pressure port providing a low pressure signal, the low pressure signal provided using the obstruction body; and an auxiliary pressure port providing an auxiliary pressure signal from a tap in a wall of the fluid conduit that is directed towards the obstruction body; wherein the pressure port providing a high pressure signal, the pressure port providing a low pressure signal, and the auxiliary pressure port providing an auxiliary pressure signal generate at least a primary differential pressure measurement signal and an auxiliary differential pressure measurement signal; further comprising meter electronics configured to: provide a baseline relationship between the primary differential pressure measurement signal and the auxiliary differential pressure measurement signal; and determine, at a later time, a second baseline relationship between the primary differential pressure measurement signal and the auxiliary differential pressure measurement signal. ### Claim 7 (depends on 6) The flow metering apparatus of claim 6, wherein the meter electronics are further configured to compare the baseline relationship to the second baseline relationship. ### Claim 8 (depends on 7) The flow metering apparatus of claim 7, wherein the meter electronics are further configured to provide an indication in response to the baseline relationship and the second baseline relationship differing by a predetermined amount. ### Claim 9 (depends on 8) The flow metering apparatus of claim 8, wherein the meter electronics are further configured to generate an alarm in response to the baseline relationship and the second baseline relationship differing by the predetermined amount. ### Claim 10 (depends on 6) The flow metering apparatus of claim 6, wherein the auxiliary pressure port is directed between the pressure port providing a high pressure signal and the pressure port providing a low pressure signal. ### Claim 11 A flow metering apparatus for a fluid conduit, comprising: a fluid conduit having an obstruction body therein; a pressure port providing a high pressure signal; a pressure port providing a low pressure signal, the low pressure signal provided using the obstruction body; a third pressure port providing an auxiliary pressure signal from a tap in a wall of the fluid conduit that is directed towards the obstruction body; wherein the pressure port providing a high pressure signal, the pressure port providing a low pressure signal, and the third pressure port providing an auxiliary pressure signal generate at least a primary differential pressure measurement signal and an auxiliary differential pressure measurement signal; and meter electronics configured to generate an indication responsive to determining that a relationship between the primary differential pressure measurement signal and the auxiliary differential pressure measurement signal has changed over time.