# US 2018/0128796 A1 · Beta-phase indicator > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2018/0128796 A1 - Document ID: US20180128796A1 - Status: Published application - Kind: A1 - Application number: 15/643,467 - Filed: 2017-07-06 - Published: 2018-05-10 - Earliest claimed: 2016-07-06 - Assignees: ElectraWatch, Inc. - Applicants: ElectraWatch, Inc. - Inventors: Ryan C. Dunn - Web page: https://patentgrep.com/patent/US20180128796A1 ## CPC - G01N 33/20: Metals - G01N 31/22: using chemical indicators (G01N31/02 takes precedence) - G01N 31/221: {for investigating pH value} - 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 A quick, non-destructive and inexpensive test is disclosed to determine whether a portion of a structure made of 5XXX Aluminum alloy is sensitized. Unlike the current sensitization tests, this test can be performed by non-skilled personnel without complicated procedures and equipment. Since the test is non-destructive, it does not require the removal material from the structure. This feature makes the test particularly attractive for in situ applications such as for use on existing structures like ships. The test requires the application of an indicating chemical to the surface of the material being tested. The indicating chemical has a pre-determined pH which may be either acidic or alkaline. The indicating chemical also contains an pH indicator of pre-determined value. After a short period of time has elapsed, the percentage of pH color change observed from the indicating chemical can be used to determine whether the sample is sensitized or not. It is also possible to obtain at least an approximation of the Degree of Sensitization of the structure using the test. ## Claims ### Claim 1 A method of determining whether or not a portion of a metallic structure comprising 5XXX Aluminum alloy is sensitized comprising the steps of: cleaning the metallic structure portion to bare metal; applying an indicating chemical with a pre-determined pH and a predetermined pH indicator to a portion of a metallic structure comprising 5XXX Aluminum alloy; allowing a pre-determined amount of time to pass; observing any change in the color of the indicating chemical; and, determining if said portion of said metallic structure comprising 5XXX Aluminum alloy is sensitized by the amount of any observed color change in the indicating chemical. ### Claim 2 (depends on 1) The method of claim 1 wherein the pH of the indicating chemical is mildly acidic i.e., less than or equal to 2. ### Claim 3 (depends on 1) The method of claim 1 wherein the pH of the indicating chemical is less than about 11 and greater than about 8. ### Claim 4 (depends on 1) The method of claim 1 wherein the pH of the indicating chemical is approximately 10. ### Claim 5 (depends on 1) The method of claim 1 wherein the metallic structure comprises a ship comprising 5XXX Aluminum alloy and the step of applying an indicating chemical to a portion of a metallic structure comprising 5XXX Aluminum alloy is performed in situ. ### Claim 6 (depends on 5) The method of claim 5 wherein the indicating chemical further comprises a thickening agent and wherein the step of applying an indicating chemical further comprises spraying the indicating chemical upon a pre-determined area of a large structure comprising 5XXX Aluminum alloy. ### Claim 7 (depends on 6) The method of claim 6 wherein the large structure is a portion of a ship comprising 5XXX Aluminum alloy. ### Claim 8 (depends on 6) The method of claim 6 wherein the large structure is a vertical bulkhead on a ship comprising 5XXX Aluminum alloy. ### Claim 9 (depends on 1) The method of claim 1 wherein the degree of sensitization of the portion of a metallic structure comprising 5XXX Aluminum alloy is also determined and wherein the degree of sensitization is determined by plotting the amount of color change in said indicating chemical against the amount of time necessary to obtain said color change. ### Claim 10 A method of determining whether or not a portion of a metallic structure comprising 5XXX Aluminum alloy is sensitized comprising the steps of: cleaning the metallic structure portion to bare metal; measuring the temperature of the metallic structure portion; applying an indicating chemical with a pre-determined pH and a predetermined pH indicator to a portion of a metallic structure comprising 5XXX Aluminum alloy; observing any change in the color of the indicating chemical while measuring the amount of time elapsed to achieve the color change; and, determining the degree of sensitization of said metallic structure by using the time at the measured temperature needed to achieve the observed color change in the indicating chemical. ### Claim 11 (depends on 10) The method of claim 10 wherein the pH of the indicating chemical is mildly acidic i.e., less than or equal to 2. ### Claim 12 (depends on 10) The method of claim 10 wherein the pH of the indicating chemical is less than about 11 and greater than about 8. ### Claim 13 (depends on 10) The method of claim 10 wherein the pH of the indicating chemical is approximately 10. ### Claim 14 (depends on 10) The method of claim 10 wherein the metallic structure comprises a ship comprising 5XXX Aluminum alloy and the step of applying an indicating chemical to a portion of a metallic structure comprising 5XXX Aluminum alloy is performed in situ. ### Claim 15 A method of determining whether or not a portion of a metallic structure comprising 5XXX Aluminum alloy is sensitized comprising the steps of: cleaning the metallic structure portion to bare metal; measuring the temperature of the metallic structure portion; applying an indicating chemical with a pre-determined pH and a predetermined pH indicator to a portion of a metallic structure comprising 5XXX Aluminum alloy; allowing the test to proceed for a pre-determined fixed amount of time based upon the measured temperature of the metallic structure portion; observing any change in the color of the indicating chemical at the end of the pre-determined amount of time; and, determining the degree of sensitization of said metallic structure by using the color change in the indicating chemical at the end of the pre-determined amount of time. ### Claim 16 (depends on 15) The method of claim 15 wherein the pH of the indicating chemical is mildly acidic i.e., less than or equal to 2. ### Claim 17 (depends on 15) The method of claim 15 wherein the pH of the indicating chemical is less than about 11 and greater than about 8. ### Claim 18 (depends on 15) The method of claim 15 wherein the pH of the indicating chemical is approximately 10. ### Claim 19 (depends on 15) The method of claim 15 wherein the metallic structure comprises a ship comprising 5XXX Aluminum alloy and the step of applying an indicating chemical to a portion of a metallic structure comprising 5XXX Aluminum alloy is performed in situ. ### Claim 20 A method of determining whether or not a portion of a metallic structure comprising 5XXX Aluminum alloy is sensitized comprising the steps of: cleaning the metallic structure portion to bare metal; maintaining the temperature of the metallic structure portion at a pre-determined temperature; applying an indicating chemical with a pre-determined pH and a predetermined pH indicator to a portion of a metallic structure comprising 5XXX Aluminum alloy; allowing the test to proceed for a pre-determined fixed amount of time; observing any change in the color of the indicating chemical at the end of the pre-determined amount of time; and, determining the degree of sensitization of said metallic structure by using the color change in the indicating chemical at the end of the pre-determined amount of time. ### Claim 21 (depends on 20) The method of claim 20 wherein the pH of the indicating chemical is mildly acidic i.e., less than or equal to 2. ### Claim 22 (depends on 20) The method of claim 20 wherein the pH of the indicating chemical is less than about 11 and greater than about 8. ### Claim 23 (depends on 20) The method of claim 20 wherein the pH of the indicating chemical is approximately 10. ### Claim 24 (depends on 20) The method of claim 20 wherein the metallic structure comprises a ship comprising 5XXX Aluminum alloy and the step of applying an indicating chemical to a portion of a metallic structure comprising 5XXX Aluminum alloy is performed in situ. ### Claim 25 (depends on 20) The method of claim 20 wherein the pre-determined temperature is approximately 50° C.