The disclosure relates to a method for determining and/or monitoring the state of a transformer oil, comprising the steps of a) performing an acoustic spectroscopy of the transformer oil, multiple ultrasonic emission signals of different frequencies and/or amplitudes being emitted into the transformer oil and corresponding reflected and/or transmitted ultrasonic reception signals of different frequencies and/or amplitudes being received after having passed through the transformer oil; and b) comparing the ultrasonic emission signals with the corresponding ultrasonic reception signals, an n-dimensional function characteristic of the transformer oil being ascertained; and c) matching the ascertained characteristic n-dimensional function from step b) with a reference function of corresponding dimension known for transformer oils, a reference transformer oil being determined; and d) registering a first value of at least one characteristic physical property of the transformer oil; and e) comparing the first value with a corresponding value of the reference transformer oil; and f) ascertaining the state of the transformer oil based on the comparison performed in step e).

Furthermore, the disclosure relates to a device (100, 200) for determining and/or monitoring the state of a transformer oil.

Methods, systems, and devices for downhole evaluation using a sensor assembly that includes a sensor plate, wherein a surface of the sensor plate forms a portion of a surface of a downhole tool. Methods include bringing the surface of the sensor plate into contact with downhole fluid; generating a guided wave that propagates in the sensor plate by activating the sensor assembly at at least one frequency configured to excite both a symmetric mode and an anti-symmetric mode; making at least one first attenuation measurement of the symmetric mode of the guided wave; making at least one second attenuation measurement of the anti-symmetric mode of the guided wave; and using the at least one first attenuation measurement and the at least one second attenuation measurement to estimate at least one parameter of interest of the fluid. Methods may include submerging the surface of the sensor plate in a downhole fluid.

A method for determining mineralogical or geochemistry of at least one geological sample with vibrational spectroscopy combined with laser-induced breakdown spectral measurements performed on the geological sample in a time variant manner with spectral acquisitions made after each of a plurality of measurement shots, spectral pre-processing performed as necessary, and subsequent analysis is applied to the collected data to determine at least one mineralogical or geochemistry parameter of the sample. The method can provide a rapid method to estimate mineralogy or geochemical parameters of a sample, which does not require sample preparation, and which can be non-destructive with respect to portions of the sample. A system for performing the method also is provided.

A system and method for detection of coking in a fuel. The system including a fuel system for delivery of fuel, a fuel contamination sensor having a contamination detection sensor with input and output transducers immersed in the fuel, a controller in operable communication with the fuel contamination sensor, the controller configured to execute a method for detection of coking in fuel. The method including generating an excitation signal for the contamination detection sensor, receiving at a controller operably connected to the contamination detection sensor, a sensor output signal from the output transducer, comparing the sensor output signal with the excitation signal, diagnosing a condition of the fuel based on a the comparing, and indicating a condition of coking based on the diagnosing. The system also includes an enunciator to indicate the detection of coking in the fuel.

A fluid sensor including a sensing area configured to receive a fluid. The fluid sensor includes a transducer and a capacitive sensor. The transducer is configured to output an ultrasonic wave through the fluid. The capacitive sensor includes a capacitive plate configured to reflect the ultrasonic wave toward the transducer.

The present disclosure relates to vibration frequency sensors comprising a vibratable flow tube having an interior for receiving a fluid, a vibration detector coupled to the flow tube for detecting a frequency of the fluid received by the flow tube during vibration thereof; and measurement circuitry coupled to the vibration detector for determining a frequency shift over time of the detected frequency. At least a portion of a surface of the interior of the flow tube is functionalized with a reactant sensitive to the analyte, and the frequency shift corresponds to the presence of the analyte, the analyte having reacted with the reactant.

A method for determining mineralogical or geochemistry of at least one geological sample with vibrational spectroscopy combined with laser-induced breakdown spectral measurements performed on the geological sample in a time variant manner with spectral acquisitions made after each of a plurality of measurement shots, spectral pre-processing performed as necessary, and subsequent analysis is applied to the collected data to determine at least one mineralogical or geochemistry parameter of the sample. The method can provide a rapid method to estimate mineralogy or geochemical parameters of a sample, which does not require sample preparation, and which can be non-destructive with respect to portions of the sample. A system for performing the method also is provided.

The invention relates to a device (01) for examining a test material (02) via acoustic spectroscopy, comprising a measuring distance (37) which is formed from a reference material (38) and the test material (02), the acoustic material parameters of the reference material (38) being known for different frequencies, and the length (x.sub.R) of the reference material (38) being known, and the length (x.sub.M) of the test material (02) being known, and comprising an ultrasonic transmission device (39) for transmitting an ultrasonic transmission signal (42) having an initial amplitude (A.sub.0) through the measuring distance (37), and comprising a first ultrasonic reception device (41) for receiving the transmitted ultrasonic reception signal (44) after said signal (44) has passed through the measuring distance (37), and comprising a second ultrasonic reception device (40) for receiving the ultrasonic receiving signal (45) reflected on the boundary surface (43) between the test material (02) and the reference material (38) after said signal (45) has twice passed through the reference material (38) or test material, said transmission device (39) being configured for giving ultrasonic transmission signals (42) having different frequencies (f) and the two reception devices (40, 41) being configured for receiving corresponding ultrasonic reception signals (44, 45) having different frequencies.

A fluid induced instability detection system and method is provided to monitor various vibration characteristics of a turbomachine. The fluid induced instability detection system detects abnormalities in the vibration data and provides an indication of one or more potential faults in the turbomachine.

In one example embodiment, a fluid induced instability detection system is provided that monitors various vibration characteristics of a turbomachine, collects vibration data in real-time, and uses the vibration data to detect and analyze changes in various operating parameters such as vibration, speed, and loading conditions, and to provide an indication of a vibration anomaly and/or potential operational risk in one or more components of the turbomachine. The vibration data can be particularly associated with certain components that are directly or indirectly impacted by a modification in process fluid flow characteristics or lubrication oil flow characteristics in the turbomachine due to various reasons such as process fluid flow disturbances, lubricating oil flow disturbances, and/or a change in turbomachine operational parameters. The fluid induced instability detection system detects abnormalities in the vibration data and provides an indication of one or more potential faults in the turbomachine.