# US 7,466,400 B2 · Device and method for automatically detecting at least one fluorescent and/or light absorbing indicator contained in a liquid service fluid during the process of filling the service fluid into a machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,466,400 B2 - Document ID: US7466400B2 - Status: Granted - Kind: B2 - Application number: 10/559,552 - Filed: 2004-05-25 - Published: 2007-03-22 - Granted: 2008-12-16 - Earliest claimed: 2003-06-04 - Assignees: Fuchs Petrolub SE - Inventors: Rolf Luther; Christian Seyfert; Fritz Stumm - Web page: https://patentgrep.com/patent/US7466400B2 ## CPC - G01N 21/64: Fluorescence; Phosphorescence - 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 2021/6439: {with indicators, stains, dyes, tags, labels, marks} - 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 method and a device for the automatic detection of at least one fluorescent and/or light-absorbent indicator contained in a liquid service fluid during the filling of a machine, in particular a combustion engine of a vehicle, with said service fluid are provided. Detection takes place in the following manner: irradiation during the filling of the service fluid to be analyzed using at least one light source (3) in a measuring section (2); capture of the light (14) passing through the service fluid in the measuring section (2) and/or emanating from the indicator contained in said fluid as a result of a fluorescent effect, by means of a light collector (5), the intensity of the light being influenced by the indicator or indicators or the concentration thereof; generation of at least one measurement signal (8, 9) representing the intensity of the light that strikes. ## Claims ### Claim 1 A machine comprising: a device for automatically detecting at least one fluorescing and/or light-absorbing indicator contained in a liquid service fluid during a process of filling the service fluid into the machine, the device including a filler tube for the service fluid, the service fluid to be poured in reaching a service fluid supply of the machine through the filler tube, and further including a measurement section made of a translucent material, the measurement section at least partially filled with or traversed by a flow of the service fluid when filling the service fluid into the filler tube, the device further including at least one light source radiating onto the measurement section and an opto-receiver onto which the light impinges, the light being transmitted through the service fluid when the service fluid flows through the measurement section and/or emanating from the indicator due to a fluorescent effect, and which generates at least one measurement signal as a function of an intensity of the light impinging on the opto-receiver, the device including an evaluation unit evaluating at least one measurement signal of the opto-receiver; wherein the filler tube leads into the measurement section. ### Claim 2 (depends on 1) The machine as recited in claim 1 wherein the opto-receiver has at least two light sensors whose frequency regions are distinct from one another, and which each generate one measurement signal. ### Claim 3 (depends on 1) The machine as recited in claim 1 wherein the light source and the opto-receiver are oriented to the measurement section and are positioned around the same at an angle of 0° to 170°. ### Claim 4 (depends on 1) The machine as recited in claim 1 wherein, in a direction of flow upstream of the measurement section, the filler tube has a reduced cross-sectional area in the section leading into the measurement section. ### Claim 5 (depends on 1) The machine as recited in claim 1 wherein the measurement section includes a measuring tube leading directly or indirectly into the service fluid supply of the machine. ### Claim 6 (depends on 1) The machine as recited in claim 1 wherein a plurality of light sources are provided, which radiate in frequency regions that are distinct from one another. ### Claim 7 (depends on 6) The machine as recited in claim 6 wherein the light sources are constituted of LEDs and/or of laser diodes having different wavelengths. ### Claim 8 (depends on 1) The machine as recited in claim 1 wherein the machine is an engine of a vehicle. ### Claim 9 (depends on 1) The machine as recited in claim 1 wherein the service fluid is lubricating oil, engine oil or hydraulic oil. ### Claim 10 A method for automatically detecting at least one fluorescing and/or light-absorbing indicator contained in a liquid service fluid during the process of filling the service fluid into a machine through a device integrated in the machine, the method comprising the following steps: filling the liquid service fluid to be detected into a filler tube, through which the service fluid arrives in the service fluid supply of the machine, and the liquid service fluid at least partially filling or flowing through a measurement section; irradiating the liquid service fluid in the measurement section by at least one light source; intercepting the light transmitted through the service fluid in the measurement section and/or emanating from the indicator contained in the same due to a fluorescent effect, by an opto-receiver, an intensity of the light being influenced by the at least one indicator or the concentration thereof, generating at least one measurement signal indicative of the intensity of the light impinging on the opto-receiver; and evaluating the at least one measurement signal in an evaluation unit and comparing the measurement signal to stored values. ### Claim 11 (depends on 10) The method as recited in claim 10 wherein the at least one indicator is a fluorescing dye which is excited by the light source in the measurement section to a fluorescent radiation; and the fluorescent radiation constitutes at least one portion of the light intercepted by the opto-receiver. ### Claim 12 (depends on 10) The method as recited in claim 10 wherein the service fluid contains at least two indicators that are active in different frequency regions; and the indicators are detected by at least two sensors of the opto-receiver that are sensitive in the different frequency regions. ### Claim 13 (depends on 12) The method as recited in claim 12 wherein concentrations of the indicators. ### Claim 14 (depends on 10) The method as recited in claim 10 wherein the measurement signal generated by the opto-receiver correlates with a concentration of the at least one indicator in the service fluid. ### Claim 15 (depends on 10) The method as recited in claim 10 wherein one of the indicators of the service fluid forms a reference indicator on whose basis the opto-receiver generates a reference signal. ### Claim 16 (depends on 15) The method as recited in claim 15 wherein the evaluation unit evaluates the at least one measurement signal on the basis of a ratio of the intensity of the at least one measurement signal to the intensity of the reference signal. ### Claim 17 (depends on 10) The method as recited in claim 10 wherein the evaluation unit assigns a quality signal to the at least one measurement signal. ### Claim 18 (depends on 17) The method as recited in claim 17 wherein the quality signal is used for automatically determining a time for the next service fluid replacement. ### Claim 19 (depends on 10) The method as recited in claim 10 wherein the machine is an engine of a vehicle. ### Claim 20 (depends on 10) The method as recited in claim 10 wherein the service fluid is lubricating oil, engine oil or hydraulic oil.