# US 12,761,131 B2 · Systems, methods and devices for monitoring fluid condition > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,761,131 B2 - Document ID: US12761131B2 - Status: Granted - Kind: B2 - Application number: 19/375,391 - Filed: 2025-10-31 - Published: 2026-05-21 - Granted: 2026-10-13 - Earliest claimed: 2024-11-19 - Assignees: GasTOPS Ltd. - Applicants: Gastops Ltd. - Inventors: Oleg Sosnovski; Timothy Mack; Marianna Marx Vieira; Alexander E. Dudelzak - Web page: https://patentgrep.com/patent/US12761131B2 ## CPC - F01M 11/10: Indicating devices; Other safety devices - G01N 21/645: {Specially adapted constructive features of fluorimeters} - G01N 21/8507: {Probe photometers, i.e. with optical measuring part dipped into fluid sample} - G01N 2021/6417: {Spectrofluorimetric devices} - G01N 2021/6484: {Optical fibres} - F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING - 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 Various methods and systems for monitoring one or more characteristics of a fluid in a mechanical device are disclosed herein. In at least one embodiment, the system includes an optical sensor including an excitation light aperture and an emission light aperture. The excitation light aperture transmits an excitation light to the fluid and the emission light aperture receives an emission light from the fluid. The system may further include an inductive sensor including a printed circuit board including a first field coil trace, a second field coil trace, and a sense coil trace. The methods disclosed include transmitting the excitation light to the fluid; receiving the emission light from the fluid; and operating a processor to obtain one or more fluorescence spectra based on the received emission light; and determine a fluid condition indicator and/or a remaining useful life of the fluid based on the one or more fluorescence spectra. ## Claims ### Claim 1 An optical sensing system for monitoring one or more properties of a fluid in a mechanical device, the optical sensing system comprising: a probe, wherein at least a portion of the probe is insertable into the fluid, the probe comprising: one or more light sources configured to transmit excitation light toward the fluid; a detector configured to receive light emitted from the fluid; a window disposed between the one or more light sources and the fluid, the window comprising an optically transparent material configured to allow transmission of the excitation light and the emitted light, wherein the optical sensing system is configured to determine at least one characteristic of the fluid based on the received light; and at least one fiber optic strand coupled between the window and the one or more light sources and the detector; at least one temperature sensor housed in the probe; and a processor coupled to the probe, the processor being configured to: obtain one or more fluorescence spectra based on the received emission light; obtain temperature data from the at least one temperature sensor; processes the obtained fluorescence spectra based on the temperature data; and determine a remaining useful life of the fluid based on the processed one or more fluorescence spectra. ### Claim 2 (depends on 1) The optical sensing system of claim 1, wherein the at least one fiber optic strand has a corresponding diameter approximately between 1 micron and 1000 microns. ### Claim 3 (depends on 1) The optical sensing system of claim 1, wherein the at least one fiber optic strand is configured to relay the excitation light from the light source to the window, and the emitted light from the window to the detector. ### Claim 4 (depends on 1) The optical sensing system of claim 1, wherein the one or more light sources system-comprise at least two light emitting devices connected either in a series or in a parallel configuration. ### Claim 5 (depends on 4) The optical sensing system of claim 4, wherein the light emitting devices comprise either a light emitting diode (LED) or a non-light emitting diode (LED) based light source. ### Claim 6 (depends on 1) The optical sensing system of claim 1, wherein at least a portion of the probe has a generally cylindrical shape. ### Claim 7 (depends on 6) The optical sensing system of claim 6, wherein the probe comprises concentric portions having a width ratio in the range of about 1000 to 1.01. ### Claim 8 (depends on 1) The optical sensing system of claim 1, wherein a width of the probe is in the range of about 1 millimeter and 1000 millimeters. ### Claim 9 (depends on 1) The optical sensing system of claim 1, wherein the optical sensing system is based on fluorescence spectrometry. ### Claim 10 (depends on 1) The optical sensing system of claim 1, wherein the emitted light received by the detector is processed, by the processor, to determine one or more of an oxidative property of the fluid, an additive concentration of the fluid, a contamination level of the fluid and a degradation state of the fluid. ### Claim 11 (depends on 1) The optical sensing system of claim 1, wherein the window comprises an optically transparent material configured to transmit light in at least one of the ultraviolet and visible wavelength ranges. ### Claim 12 (depends on 1) The optical sensing system of claim 1, wherein the window comprises an optically transparent material configured to transmit light in a near infrared and infrared wavelength range. ### Claim 13 (depends on 1) The optical sensing system of claim 1, wherein the window comprises at least one of sapphire and quartz. ### Claim 14 (depends on 1) The optical sensing system of claim 1, further comprising one or more of an inductive sensor, an electrical properties sensor and a viscosity sensor, and wherein at least one of the one or more of an inductive sensor, an electrical properties sensor and a viscosity sensor is housed in the probe. ### Claim 15 (depends on 1) The optical sensing system of claim 1, wherein the processor is configured to determine the remaining useful life of the fluid based on the one or more fluorescence spectra by: obtaining a secondary dataset comprising one or more fluid parameters of the fluid; and correlating the one or more fluorescence spectra to the secondary dataset. ### Claim 16 (depends on 15) The optical sensing system of claim 15, wherein the one or more fluid parameters comprises an acid number, a base number, an oxidation number, or a viscosity of the fluid. ### Claim 17 (depends on 1) The optical sensing system of claim 1, wherein the fluid comprises one or more of a lubricant oil, a fuel, a hydraulic oil, a transmission oil, a thermal transfer fluid, and a coolant. ### Claim 18 (depends on 1) The system of claim 1, wherein the one or more properties comprises one or more of an additive concentration of the fluid, a contamination level of the fluid, an oxidative stability level of the fluid, a degradation level of the fluid, an acid number associated with the fluid, a base number associated with the fluid, and a thermal stability level of the fluid. ### Claim 19 (depends on 5) The system of claim 5, wherein the non-LED based light source comprises at least one of a gas phase laser, a solid-state laser, a high pressure hollow cathode lamp, a low pressure hollow-cathode lamp, an arc lamp with monochromators and an arc lamp without monochromators. ### Claim 20 (depends on 1) The system of claim 1, wherein the window comprises a multilayer optical element having at least one layer of sapphire and at least one layer of quartz.