# US 11,079,318 B2 · Gas sensing device and a method for sensing gas > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,318 B2 - Document ID: US11079318B2 - Status: Granted - Kind: B2 - Application number: 16/081,953 - Filed: 2017-03-09 - Published: 2020-09-17 - Granted: 2021-08-03 - Earliest claimed: 2016-03-10 - Assignees: Todos Technologies Ltd.; Technion Research & Development Foundation Limited - Applicants: Todos Technologies Ltd.; Technion Research and Developement Foundation Ltd. - Inventors: Yael Nemirovsky; Amikam Nemirovsky - Web page: https://patentgrep.com/patent/US11079318B2 ## CPC - G01N 21/31: Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry {(G01N21/72 takes precedence)} - G01N 21/3504: for analysing gases, e.g. multi-gas analysis - G01N 21/314: {with comparison of measurements at specific and non-specific wavelengths (dual wavelength spectrometry G01J3/427)} - G01N 33/0027: {concerning the detector} - G01N 2021/3166: {using separate detectors and filters} - G01N 2021/3531: {without instrumental source, i.e. radiometric} - G01N 2201/0221: Portable; cableless; compact; hand-held - 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) ## Abstract There is provided a gas sensing device for sensing a certain gas that is associated with a certain spectral band, the gas sensing device may include a passive gas sensor that is configured to generate passive gas sensor detection signals that are responsive to the certain spectral band; a passive dummy sensor that is configured to generate passive dummy sensor detection signals that are indifferent to the certain spectral hand; and at least one circuit that is configured to detect a presence or absence of the certain gas within a certain volume that is located within the fields of view of the passive gas sensor and the passive dummy sensor based on a comparison between the passive gas sensor detection signals and the passive dummy sensor detection signals. ## Claims ### Claim 1 A gas sensing device for sensing a certain gas that is associated with a certain spectral band, the gas sensing device comprises: a passive gas sensor that is configured to generate passive gas sensor detection signals that are responsive to the certain spectral band; a passive dummy sensor that is configured to generate passive dummy sensor detection signals that are indifferent to the certain spectral band; and at least one circuit that is configured to detect a presence or absence of the certain gas within a certain volume that is located within a field of view of the passive gas sensor and a field of view the passive dummy sensor based on a comparison between the passive gas sensor detection signals and the passive dummy sensor detection signals; wherein a detection of the presence or absence of the certain gas within the certain volume is based on comparisons between passive gas sensor detection signals obtained during multiple measurements and passive dummy sensor detection signals obtained during the multiple measurements; wherein the multiple measurements comprise a first measurement and a second measurement; wherein the first measurement was taken when the gas sensing device was positioned at a first position (a) that is on a floor of a room and facing a ceiling and (b) in which the passive gas sensor has a first optical length; wherein the second measurement was taken when the gas sensing device was positioned at a second position (a) that is on a head of a user and facing the ceiling, and (b) in which the passive gas sensor has a second optical length that differs by a known difference from the first optical length. ### Claim 2 (depends on 1) The gas sensing device according to claim 1 wherein the at least one circuit is configured to detect the presence or absence of the certain gas within the certain volume regardless of the optical length of each one of the passive gas sensor and the passive dummy sensor. ### Claim 3 (depends on 1) The gas sensing device according to claim 1 wherein the at least one circuit is configured to detect the presence or absence of the certain gas within the certain volume based on an optical length of each one of the passive gas sensor and the passive dummy sensor. ### Claim 4 (depends on 3) The gas sensing device according to claim 3 wherein the at least one circuit is configured to receive information about the optical length. ### Claim 5 (depends on 1) The gas sensing device according to claim 1 wherein the at least one circuit is configured to detect the presence or absence of the certain gas within the certain volume based, at least on ambient temperatures. ### Claim 6 (depends on 1) The gas sensing device according to claim 1 wherein the at least one circuit is configured to detect the presence or the absence of the certain gas within the certain volume based on the known difference, a first difference between passive gas sensor detection signals obtained during the first measurement and passive dummy sensor detection signals obtained during the first measurement, and a second difference between passive gas sensor detection signals obtained during the second measurement and passive dummy sensor detection signals obtained during the second measurement. ### Claim 7 (depends on 6) The gas sensing device according to claim 6 wherein the at least one circuit is configured to detect the presence or the absence of the certain gas within the certain volume based on an absolute value of a ratio between the second difference and the first difference. ### Claim 8 (depends on 7) The gas sensing device according to claim 7 wherein the at least one circuit is configured to detect a concentration of the certain gas within the certain volume by: dividing (a) the absolute value of the ratio between the second difference and the first difference, by (b) a product of the known difference multiplied by a gas absorption coefficient of the certain gas at a wavelength of detection of the passive gas sensor. ### Claim 9 (depends on 1) The gas sensing device according to claim 1 wherein the at least one circuit comprises a man machine interface for outputting instructing for positioning the gas sensing device at the first position and for outputting instructions for positioning the gas sensing device at the second position. ### Claim 10 (depends on 1) The gas sensing device according to claim 1 wherein the at least one circuit s configured to calculate the second position. ### Claim 11 (depends on 1) The gas sensing device according to claim 1 wherein the gas sensing device is a smartphone. ### Claim 12 A method for sensing a certain gas that is associated with a certain spectral band, the method comprises: generating, by a passive gas sensor of a gas sensing device, passive gas sensor detection signals that are responsive to the certain spectral band; generating, by a passive dummy sensor of a gas sensing device, passive dummy sensor detection signals that are indifferent to the certain spectral band; and detecting, by at least one circuit, a presence or absence of the certain gas within a certain volume that is located within a field of view of the passive gas sensor and a field of view of the passive dummy sensor based on a comparison between the passive gas sensor detection signals and the passive dummy sensor detection signals; wherein the detecting of the presence or absence of the certain gas within the certain volume is based on comparisons between passive gas sensor detection signals obtained during multiple measurements and passive dummy sensor detection signals obtained during the multiple measurements; wherein the multiple measurements comprise a first measurement and a second measurement; wherein the first measurement was taken when the gas sensing device was positioned at a first position (a) that is on a floor of a room and facing a ceiling and (b) in which the passive gas sensor has a first optical length; wherein the second measurement was taken when the gas sensing device was positioned at a second position (a) that is on a head of a user and facing the ceiling, and (b) in which the passive gas sensor has a second optical length that differs by a known difference from the first optical length. ### Claim 13 (depends on 12) The method according to claim 12 comprising detecting the presence or absence of the certain gas within the certain volume regardless of the optical length of each one of the passive gas sensor and the passive dummy sensor. ### Claim 14 (depends on 12) The method according to claim 12 comprising detecting the presence or absence of the certain gas within the certain volume based on an optical length of each one of the passive gas sensor and the passive dummy sensor. ### Claim 15 (depends on 14) The method according to claim 14 comprising receiving information about the optical length. ### Claim 16 (depends on 12) The method according to claim 12 comprising detecting the presence or absence of the certain gas within the certain volume based, at least on ambient temperatures. ### Claim 17 (depends on 12) The method according to claim 12 comprising detecting the presence or the absence of the certain gas within the certain volume based on the known difference, a first difference between passive gas sensor detection signals obtained during the first measurement and passive dummy sensor detection signals obtained during the first measurement, and a second difference between passive gas sensor detection signals obtained during the second measurement and passive dummy sensor detection signals obtained during the second measurement. ### Claim 18 (depends on 17) The method according to claim 17 comprising detecting the presence or the absence of the certain gas within the certain volume based on an absolute value of a ratio between the second difference and the first difference. ### Claim 19 (depends on 18) The method according to claim 18 comprising detecting a concentration of the certain gas within the certain volume by: dividing (a) the absolute value of the ratio between the second difference and the first difference, by (b) a product of the known difference multiplied by a gas absorption coefficient of the certain gas at a wavelength of detection of the passive gas sensor. ### Claim 20 (depends on 12) The method according to claim 12 comprising outputting instructions for positioning the gas sensing device at the first position and for outputting instructions for positioning the gas sensing device at the second position. ### Claim 21 (depends on 12) The method according to claim 12 comprising calculating the second position. ### Claim 22 (depends on 12) The method according to claim 12 wherein the gas sensing device is a smartphone.