# US 2017/0284869 A1 · Temperature measurement system for furnaces > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0284869 A1 - Document ID: US20170284869A1 - Status: Published application - Kind: A1 - Application number: 15/088,833 - Filed: 2016-04-01 - Published: 2017-10-05 - Earliest claimed: 2016-04-01 - Assignees: LumaSense Technologies Holdings, Inc. - Applicants: LumaSense Technologies Holdings, Inc. - Inventors: Tim Patrick Dubbs; John Leonard Shaver; Kreg James Kelley - Web page: https://patentgrep.com/patent/US20170284869A1 ## CPC - G01J 5/0044: {Furnaces, ovens, kilns (G01J5/0007, G01J5/004 take precedence)} - G01J 5/03: Arrangements for indicating or recording specially adapted for radiation pyrometers - G01J 5/07: Arrangements for adjusting the solid angle of collected radiation, e.g. adjusting or orienting field of view, tracking position or encoding angular position (optical collimating elements G01J5/0806) - G06V 10/235: {based on user input or interaction} - G06V 10/60: relating to illumination properties, e.g. using a reflectance or lighting model - H04N 23/23: from thermal infrared radiation - H04N 23/90: Arrangement of cameras or camera modules, e.g. multiple cameras in TV studios or sports stadiums - G01J 5/80: Calibration (using comparison with reference sources G01J5/52) - G01J 5/802: {by correcting for emissivity} - G01J 5/804: {using atmospheric correction} - G01J 2005/0077: {Imaging} - G01J: MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY (light sources F21, H01J, H01K, H05B; investigating properties of materials by optical means G01N) - G06V: IMAGE OR VIDEO RECOGNITION OR UNDERSTANDING - H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION ## Abstract A method for measuring furnace temperatures. The method includes obtaining radiance measurements from a plurality of regions of interest (ROIs) using a plurality of thermal imaging cameras, and measuring a surface temperature using a radiance measurement obtained from an ROI selected from the plurality of ROIs. Measuring the surface temperature includes determining an effective background radiance affecting the selected ROI using radiance measurements obtained from ROIs different from the selected ROI, obtaining a compensated radiance by removing the effective background radiance from the radiance measurement obtained from the selected ROI, and converting the compensated radiance to the measured surface temperature. ## Claims ### Claim 1 A method for measuring furnace temperatures, the method comprising: obtaining radiance measurements from a plurality of regions of interest (ROIs), using a plurality of thermal imaging cameras; measuring a surface temperature using a radiance measurement obtained from an ROI selected from the plurality of ROIs, comprising: determining an effective background radiance affecting the selected ROI, using radiance measurements obtained from ROIs different from the selected ROI; obtaining a compensated radiance by removing the effective background radiance from the radiance measurement obtained from the selected ROI; and converting the compensated radiance to the measured surface temperature. ### Claim 2 (depends on 1) The method of claim 1, wherein each of the plurality of ROIs is a surface region on one selected from a group consisting of a reformer tube, a wall, a floor, a ceiling and a flame front. ### Claim 3 (depends on 1) The method of claim 1, wherein the radiance measurement obtained from the selected ROI is obtained from a plurality of pixels in the ROI, averaged over at least one selected from the group consisting of space and time. ### Claim 4 (depends on 1) The method of claim 1, wherein the radiance measurement obtained from the selected ROI is obtained from a single pixel in the ROI. ### Claim 5 (depends on 1) The method of claim 1, wherein a thermal imaging camera of the plurality of thermal imaging cameras obtains radiance measurements from multiple ROIs that are a subset of the plurality of ROIs. ### Claim 6 (depends on 1) The method of claim 1, wherein the radiance measurements are concurrently obtained; and wherein the surface temperature is measured in real-time. ### Claim 7 (depends on 1) The method of claim 1, wherein determining the effective background radiance for the selected ROI comprises: selecting surrounding surfaces that add reflected radiance to the radiance measurement obtained from the selected ROI, wherein each of the surrounding surfaces comprises at least one ROI of the plurality of ROIs; determining mean radiances of the surrounding surfaces, based on radiance measurements from the at least one ROI on each of the surrounding surfaces; determining a weighted average of the mean radiances of the surrounding surfaces, wherein the weighted average is the effective background radiance. ### Claim 8 (depends on 7) The method of claim 7, wherein the weighted average is determined based on geometric view factors of the surrounding surfaces. ### Claim 9 (depends on 1) The method of claim 1, further comprising: correcting the radiance measurement obtained from the selected ROI for an emissivity of the selected ROI. ### Claim 10 (depends on 9) The method of claim 9, wherein the emissivity is determined through comparison of the radiance measurement obtained from the selected ROI with a radiance measurement obtained from a reference body with a known emissivity, wherein a temperature of the reference body with the known emissivity is identical to a temperature of the ROI. ### Claim 11 (depends on 1) The method of claim 1, further comprising: correcting the compensated radiance signal for at least one selected from the group consisting of an atmospheric absorption and an atmospheric emission. ### Claim 12 (depends on 11) The method of claim 11, wherein the correction for the atmospheric emission is determined based on characteristics of a flame front that is traversed for the radiance measurement of the selected ROI, the characteristics of the flame front comprising at least one selected from the group consisting of: a length of the traversed flame front; a type of fuel fed to a burner generating the flame front; and a fuel flow to the burner generating the flame front. ### Claim 13 (depends on 12) The method of claim 12, wherein the correction of the atmospheric emission is dynamically updated based on the fuel flow to the burner. ### Claim 14 (depends on 1) The method of claim 1, further comprising: adjusting the measured surface temperature to match a reference surface temperature. ### Claim 15 A non-transitory computer readable medium (CRM) storing instructions for measuring furnace temperatures, the instructions comprising functionality for: obtaining radiance measurements from a plurality of regions of interest (ROIs), using a plurality of thermal imaging cameras; measuring a surface temperature using a radiance measurement obtained from an ROI selected from the plurality of ROIs, comprising: determining an effective background radiance affecting the selected ROI, using radiance measurements obtained from ROIs different from the selected ROI; obtaining a compensated radiance by removing the effective background radiance from the radiance measurement obtained from the selected ROI; and converting the compensated radiance to the measured surface temperature. ### Claim 16 (depends on 15) The non-transitory CRM of claim 15, wherein the radiance measurements are concurrently obtained; and wherein the surface temperature is measured in real-time. ### Claim 17 (depends on 15) The non-transitory CRM of claim 15, wherein the instructions further comprise functionality for: correcting the compensated radiance signal for at least one selected from the group consisting of an atmospheric absorption and an atmospheric emission, wherein the correction for the atmospheric emission is determined based on characteristics of a flame front that is traversed for the radiance measurement of the selected ROI, the characteristics of the flame front comprising at least one selected from the group consisting of: a length of the traversed flame front; a type of fuel fed to a burner generating the flame front; and a fuel flow to the burner generating the flame front. ### Claim 18 A system for measuring furnace temperatures, comprising: a plurality of thermal imaging cameras; and a processing unit configured to: obtain radiance measurements from a plurality of regions of interest (ROIs), using the plurality of thermal imaging cameras; measure a surface temperature using a radiance measurement obtained from an ROI selected from the plurality of ROIs, comprising: determining an effective background radiance affecting the selected ROI, using radiance measurements obtained from ROIs different from the selected ROI; obtaining a compensated radiance by removing the effective background radiance from the radiance measurement obtained from the selected ROI; and converting the compensated radiance to the measured surface temperature. ### Claim 19 (depends on 18) The system of claim 18, wherein the radiance measurements are concurrently obtained; and wherein the surface temperature is measured in real-time. ### Claim 20 (depends on 18) The system of claim 18, wherein the processing unit is further configured to: correct the compensated radiance signal for at least one selected from the group consisting of an atmospheric absorption and an atmospheric emission, wherein the correction for the atmospheric emission is determined based on characteristics of a flame front that is traversed for the radiance measurement of the selected ROI, the characteristics of the flame front comprising at least one selected from the group consisting of: a length of the traversed flame front; a type of fuel fed to a burner generating the flame front; and a fuel flow to the burner generating the flame front.