# US 11,029,294 B2 · Method and apparatus for measuring humidity using an electrochemical gas sensor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,029,294 B2 - Document ID: US11029294B2 - Status: Granted - Kind: B2 - Application number: 16/376,624 - Filed: 2019-04-05 - Published: 2020-10-08 - Granted: 2021-06-08 - Earliest claimed: 2019-04-05 - Assignees: Honeywell International Inc. - Applicants: Honeywell International Inc. - Inventors: Keith Pratt; Tom Gurd - Web page: https://patentgrep.com/patent/US11029294B2 ## CPC - G01N 27/4163: {checking the operation of, or calibrating, the measuring apparatus (G01N27/3274, G01N27/4175 and G01N33/0006 take precedence)} - G01N 33/0031: {comprising two or more sensors, e.g. a sensor array} - G01K 1/14: Supports; Fastening devices; Arrangements for mounting thermometers in particular locations - G01N 27/4045: {for gases other than oxygen} - G01N 27/413: Concentration cells using liquid electrolytes {measuring currents or voltages in voltaic cells} - G01N 33/0006: {Calibrating gas analysers} - G01N 33/0036: {specially adapted to detect a particular component (physical analysis of gaseous biological material G01N33/497)} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - G01K: MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR (radiation pyrometry G01J5/00) ## Abstract A gas detection apparatus and method for measuring humidity using an electrochemical gas sensor. The gas detection apparatus comprises an electrolyte-based electrochemical gas sensor and a controller configured to measure the average humidity value within an ambient environment over a period of time. The average ambient humidity value over the period of time is determined based on the average rate of change over the period of time of the electrolyte concentration within the electrolyte gas sensor of the gas detection apparatus over the period and the average temperature in the ambient environment over the period of time. The gas sensing apparatus may be configured to communicate the average ambient humidity value within the ambient environment to a second electrochemical gas sensor or a second gas detection apparatus within the same ambient environment. ## Claims ### Claim 1 A gas detection apparatus comprising: a first electrolyte-based electrochemical gas sensor configured to measure an electrolyte concentration within the first electrochemical gas sensor; a temperature sensor configured to measure a temperature of an ambient environment surrounding the first electrolyte-based electrochemical gas sensor; and a controller in communication with the first electrolyte-based electrochemical gas sensor and the temperature sensor, wherein the controller is configured to (i) determine an average ambient temperature of the ambient environment over a first period of time, (ii) determine an average rate of change of electrolyte concentration within the first electrochemical gas sensor over the first period of time, and (iii) determine, based on the average ambient temperature and the average rate of change of electrolyte concentration, an average humidity value of the ambient environment over the first period of time. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the first electrochemical gas sensor comprises a volume of acid-based electrolyte. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the controller is further configured to determine an average electrolyte water vapor pressure over a period of time. ### Claim 4 (depends on 3) The apparatus of claim 3, wherein the temperature sensor is integrated into the first electrochemical gas sensor. ### Claim 5 (depends on 1) The apparatus of claim 1, further comprising a gas detection apparatus housing, wherein the gas detection apparatus housing comprises an exterior housing portion and an interior housing portion, and wherein the first electrochemical gas sensor, the temperature sensor, and the controller are enclosed within the interior housing portion. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the average humidity value of the ambient environment over the first period of time is determined using a look-up table correlating the average rate of change of electrolyte concentration within the first electrochemical gas sensor over the first period of time to a corresponding humidity value at the average ambient temperature and an average electrolyte water vapor pressure within the first electrochemical gas sensor over the first period of time, wherein the corresponding humidity value defines the average humidity value of an ambient environment over the first period of time. ### Claim 7 (depends on 1) The apparatus of claim 1, further comprising a second electrochemical gas sensor, wherein the second electrochemical gas sensor is an electrolyte-based electrochemical gas sensor positioned within the ambient environment, and wherein the first electrochemical gas sensor is configured to communicate the average humidity value of the ambient environment over the first period of time to the second electrochemical gas sensor. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the second electrochemical gas sensor comprises a volume of non-acid-based electrolyte. ### Claim 9 (depends on 7) The apparatus of claim 7, wherein the second electrochemical gas sensor is configured to apply an appropriate compensation factor to an output of the second electrochemical gas sensor based on the average humidity value of the ambient environment over the first period of time. ### Claim 10 A method of determining humidity using an electrochemical gas sensor comprising: providing a first electrolyte-based electrochemical gas sensor configured to measure an electrolyte concentration within the first electrochemical gas sensor; providing a temperature sensor configured to measure a temperature of an ambient environment surrounding the first electrolyte-based electrochemical gas sensor providing a controller in communication with the first electrolyte-based electrochemical gas sensor and the temperature sensor, wherein the controller is configured to (i) determine an average ambient temperature of the ambient environment over a first period of time, (ii) determine an average rate of change of electrolyte concentration within the first electrochemical gas sensor over the first period of time, and (iii) determine, based on the average ambient temperature and the average rate of change of electrolyte concentration, an average humidity value of the ambient environment over the first period of time; and determining the average humidity value of the ambient environment over the first period of time based on the average ambient temperature of the ambient environment and the average rate of change of electrolyte concentration within the first electrochemical gas sensor over the first period of time. ### Claim 11 (depends on 10) The method of claim 10, wherein the first electrochemical gas sensor comprises a volume of acid-based electrolyte. ### Claim 12 (depends on 10) The method of claim 10, wherein the controller is further configured to determine an average electrolyte water vapor pressure over a period of time. ### Claim 13 (depends on 10) The method of claim 10, wherein the temperature sensor is integrated into the first electrochemical gas sensor. ### Claim 14 (depends on 13) The method of claim 13, further comprising providing a gas detection apparatus housing, wherein the gas detection apparatus housing comprises an exterior housing portion and an interior housing portion, and wherein the first electrochemical gas sensor, the temperature sensor, and the controller are enclosed within the interior housing portion. ### Claim 15 (depends on 10) The method of claim 10, wherein the average humidity value of the ambient environment over the first period of time is determined using a look-up table correlating the average rate of change of electrolyte concentration within the first electrochemical gas sensor over the first period of time to a corresponding humidity value at the average ambient temperature and an average electrolyte water vapor pressure within the first electrochemical gas sensor over the first period of time, wherein the corresponding humidity value defines the average humidity value of an ambient environment over the first period of time. ### Claim 16 (depends on 10) The method of claim 10, further comprising providing a second electrochemical gas sensor and communicating the average humidity value of the ambient environment over the first period of time from the first electrochemical gas sensor to the second electrochemical gas sensor, wherein the second electrochemical gas sensor is an electrolyte-based electrochemical gas sensor positioned within the ambient environment. ### Claim 17 (depends on 16) The method of claim 16, wherein the second electrochemical gas sensor comprises a volume of non-acid-based electrolyte. ### Claim 18 (depends on 17) The method of claim 17, further comprising applying an appropriate compensation factor to an output of the second electrochemical gas sensor based on the average humidity value of the ambient environment over the first period of time.