# US 2021/0239554 A1 · Pressure measurement device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0239554 A1 - Document ID: US20210239554A1 - Status: Published application - Kind: A1 - Application number: 17/158,201 - Filed: 2021-01-26 - Published: 2021-08-05 - Earliest claimed: 2020-01-30 - Assignees: Azbil Corporation - Applicants: Azbil Corporation - Inventors: Tomohisa TOKUDA - Web page: https://patentgrep.com/patent/US20210239554A1 ## CPC - G01L 9/0042: {Constructional details associated with semiconductive diaphragm sensors, e.g. etching, or constructional details of non-semiconductive diaphragms (details about the integration or bonding of piezoresistor in or on the diaphragm G01L9/0052 and G01L9/0057 respectively)} - G01L 9/0004: {using variations in inductance (G01L9/007 takes precedence)} - G01L 9/0052: {of piezoresistive elements (circuits therefor G01L9/06)} - G01L 15/00: Devices or apparatus for measuring two or more fluid pressure values simultaneously - G01L: MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE (weighing G01G) ## Abstract Measurement with satisfactory sensitivity in a low-pressure range, and accurate measurement in a wider pressure range, are realized by a pressure sensor that includes a diaphragm layer and a pressure receiving region formed on the diaphragm layer. The pressure sensor includes a first piezostrictive element, a second piezostrictive element, a third piezostrictive element, and a fourth piezostrictive element. In addition, the pressure sensor includes a first magnetostrictive element, a second magnetostrictive element, a third magnetostrictive element, and a fourth magnetostrictive element. A switching function unit outputs a pressure value calculated by a second calculation function unit until a pressure value calculated by a first calculation function unit exceeds a set threshold value, and outputs the pressure value calculated by the first calculation function unit when the pressure value calculated by the first calculation function unit exceeds the threshold value. ## Claims ### Claim 1 A pressure measurement device comprising: a pressure sensor; and a pressure calculation unit; wherein the pressure sensor includes a diaphragm layer, a pressure receiving region formed in the diaphragm layer, a piezostrictive measurement unit provided in the diaphragm layer in an outer peripheral portion of the pressure receiving region, and formed of a piezostrictive element that measures a strain of the pressure receiving region by using a piezoresistive effect, and a magnetostrictive measurement unit provided in the pressure receiving region of the diaphragm layer, and formed of a magnetostrictive element that is formed of a material whose magnetization is changed due to the strain, and that measures the strain of the pressure receiving region, and the pressure calculation unit includes a first calculation function unit configured to calculate a pressure value received by the pressure receiving region, based on a measurement result of the piezostrictive measurement unit, a second calculation function unit configured to calculate a pressure value received by the pressure receiving region, based on a measurement result of the magnetostrictive measurement unit, and a switching function unit configured to output the pressure value calculated by the second calculation function unit until the pressure value calculated by the first calculation function unit exceeds a set threshold value, and to output the pressure value calculated by the first calculation function unit when the pressure value calculated by the first calculation function unit exceeds the threshold value. ### Claim 2 (depends on 1) The pressure measurement device according to claim 1, wherein the piezostrictive measurement unit and the magnetostrictive measurement unit are disposed at positions where generated stress peaks in the pressure receiving region. ### Claim 3 (depends on 1) The pressure measurement device according to claim 1, wherein the piezostrictive measurement unit is disposed at a location where a piezoelectric effect is generated in the pressure receiving region. ### Claim 4 (depends on 1) The pressure measurement device according to claim 1, wherein the piezostrictive measurement unit is formed of a first piezostrictive element, a second piezostrictive element, a third piezostrictive element, and a fourth piezostrictive element which form a first bridge circuit, the magnetostrictive measurement unit is formed of a first magnetostrictive element, a second magnetostrictive element, a third magnetostrictive element, and a fourth magnetostrictive element which form a second bridge circuit, and the magnetostrictive measurement unit is disposed at a location different from that of the piezostrictive measurement unit. ### Claim 5 (depends on 1) The pressure measurement device according to claim 1, wherein the pressure receiving region has a circular shape in a plan view. ### Claim 6 (depends on 1) The pressure measurement device according to claim 1, wherein the pressure receiving region has a square shape in a plan view. ### Claim 7 (depends on 3) The pressure measurement device according to claim 3, wherein the piezostrictive measurement unit is formed of a first piezostrictive element, a second piezostrictive element, a third piezostrictive element, and a fourth piezostrictive element which form a first bridge circuit, the magnetostrictive measurement unit is formed of a first magnetostrictive element, a second magnetostrictive element, a third magnetostrictive element, and a fourth magnetostrictive element which form a second bridge circuit, and the magnetostrictive measurement unit is disposed at a location different from that of the piezostrictive measurement unit. ### Claim 8 (depends on 2) The pressure measurement device according to claim 2, wherein the pressure receiving region has a circular shape in a plan view. ### Claim 9 (depends on 3) The pressure measurement device according to claim 3, wherein the pressure receiving region has a circular shape in a plan view. ### Claim 10 (depends on 4) The pressure measurement device according to claim 4, wherein the pressure receiving region has a circular shape in a plan view. ### Claim 11 (depends on 7) The pressure measurement device according to claim 7, wherein the pressure receiving region has a circular shape in a plan view. ### Claim 12 (depends on 2) The pressure measurement device according to claim 2, wherein the pressure receiving region has a square shape in a plan view. ### Claim 13 (depends on 3) The pressure measurement device according to claim 3, wherein the pressure receiving region has a square shape in a plan view. ### Claim 14 (depends on 4) The pressure measurement device according to claim 4, wherein the pressure receiving region has a square shape in a plan view. ### Claim 15 (depends on 7) The pressure measurement device according to claim 7, wherein the pressure receiving region has a square shape in a plan view.