Ultrasonic Measurement Method Research Articles

A simultaneous ultrasonic measurement method for lubrication film thickness and coating wear depth with thermal effect

Lubrication film thickness and coating wear depth are two important parameters indicating tribological condition in tribological elements. In this paper, a new ultrasonic model was proposed to measure the lubricant film thickness and the coating wear depth simultaneously. A ratio coefficient, which was constructed by dividing the echo signal reflected from the oil film layer to that reflected from the pad-coating interface, was established, and the amplitude and phase of this ratio coefficient were used to measure the film thickness and wear depth, respectively. A pre-calibration test was conducted to help eliminate the effect of the temperature and a dynamic calibration test rig was built to construct series known oil film thickness and wear depth under various temperature. The calibration tests demonstrated that the proposed ultrasonic method could measure the lubricant film thickness and coating wear depth simultaneously under varying temperature. This paper can provide an effective means to observe the evolution characteristics between lubrication and wear.

Arrayed ultrasonic wind speed and direction measurement based on the BNF-FLOC-MUSIC algorithm

An arrayed ultrasonic wind measurement method based on the BNF-FLOC-MUSIC algorithm is proposed to address the issue of low measurement accuracy and poor noise suppression capabilities of current array wind measurement methods in impulse noise backgrounds. The proposed method utilizes an array structure consisting of one transmitting ultrasonic sensor and five receiving sensors. Continuous sampling is performed leveraging this structure, and the received array signals are processed using a bounded nonlinear function (BNF). Subsequently, the fractional lower-order covariance (FLOC) operations are applied to suppress impulse noise’s influence further. Finally, combining these steps with the Multiple Signal Classification (MUSIC) algorithm enables high-precision wind speed and direction measurement. The effectiveness and superiority of the method are examined through simulation experiments and actual measurement systems, and the errors of wind speed and wind direction angle in actual measurement are 1.2% and 2°, respectively, which satisfy the design requirements of the ultrasonic anemometer.

Utilizing ultrasonography to determine the minimal transverse diameter of the subglottic airway for informed selection of reinforced cuffed endotracheal tube models in children.

We explored the use of ultrasonography in determining the minimal transverse diameter of the subglottic airway (MTDSA) for the purpose of choosing an appropriate model of reinforced cuffed endotracheal tube. A total of 110 pediatric patients who received general anesthesia and tracheal intubation for selective surgeries at the hospital from February 2019 to February 2022 were chosen. They were then randomly assigned to three groups: 39 in the MTDSA group, 35 in the age formula group, and 36 in the height formula group. We assessed how accurately the appropriate endotracheal tube model was predicted in each group and compared their predictive performance. The age range of the enrolled pediatric patients was 3-6 years old. The ultrasonic measurement method demonstrated a prediction accuracy of 87.18%, while the age formula method and height formula method exhibited lower accuracy rates of 54.29% and 47.22%, respectively. Notably, the ultrasonic measurement method outperformed the other two methods significantly (P < 0.05). In the MTDSA group, 2 patients had their catheters changed during anesthesia, and the proportion of patients who changed their catheters was 5.13%. In the MTDSA group, 6 catheters were replaced, and the frequency of catheter replacement was 15.38%. In contrast, these percentages were much higher in the age formula group, at 31.43% and 45.71%, and in the height formula group, at 36.11% and 52.78%. The latter two groups had significantly higher values than the MTDSA group (P < 0.05). Regarding complications such as hoarseness, laryngeal edema, aspiration, and laryngospasm, the MTDSA group experienced a notably lower total incidence of 7.69% compared to the 37.14% in the age formula group and 41.67% in the height formula group, demonstrating statistical significance (P < 0.05). The ultrasonic measurement technique employed in MTDSA exhibits impressive precision when it comes to forecasting the specific model of a reinforced cuffed endotracheal tube for pediatric patients. This enhanced accuracy contributes significantly to minimizing the need for tube replacements during anesthesia and the associated complications. It holds immense importance in assisting clinicians in selecting the most appropriate pediatric endotracheal tube model for anesthesia induction.

Ultrasonic measurement method for three-dimensional assembly stress of aero-engine rotors

The precise measurement of three-dimensional stress in the rotor is a key means to ensure the assembly accuracy and operational safety of aero-engines. The unclear coupling influence mechanism of different directions of stress on ultrasonic propagation makes it challenging to establish a three-dimensional stress measurement model. This paper proposes a three-dimensional assembly stress measurement method for aero-engine rotors based on ultrasonic propagation time difference decoupling. The three-dimensional assembly stress is converted into the stress component parallel and perpendicular to the ultrasonic wave propagation direction in this method. The acoustoelastic equation including three-dimensional stress parameters is established based on the function model of different direction stress and ultrasonic wave propagation velocity. An innovative three-transducer stress measurement scheme is designed, which integrates ultrasonic wave transmitting and receiving transducers and time difference feedback transducers. The acoustoelastic equations in three propagation directions are constructed by rotating the transducer group to change the propagation direction of ultrasonic waves. Finally, the acoustoelastic equations are solved simultaneously to decouple the ultrasonic propagation time difference, thus achieving a three-dimensional assembly stress measurement of the aero-engine rotor. The experimental results show that the maximum deviation between the measured values and the simulation results in the x ,y, and z directions is 15.885 MPa, 14.113 MPa, and 17.093 MPa, respectively. This study provides effective theoretical and technical support for precisely measuring three-dimensional assembly stress in high-end equipment represented by aero-engines.

Estimating the Depths of Normal Surface Notches Using Mode-Conversion Waves at the Bottom Tip.

In this work, a two-parameter inversion problem is analyzed, related to surface crack widths for measuring depths of normal surface notches, based on a laser-based ultrasonic measurement method in the time domain. In determining the depth measurement formulas, the main technique is the time delay between reflected and scattered waves. Scattered waves are generated by two reflections along the bottom and three mode transformations at the surface of the crack tips. Moreover, the scattering angle of the mode-conversion waves is 30°. These two key factors lead to corrected item "2wβ" in the depth measurement formula. A laser-based ultrasonic experimental platform is built to generate and receive surface waves in a non-contact manner on aluminum and steel specimens with surface cracks. The depth measurement method proposed in this paper has been validated through theoretical, simulation, and experimental methods. Finally, in this paper, an effective approach for quantitatively measuring crack depths, based on laser ultrasound, using the time-domain properties of surface wave propagation is provided.

A novel laser-EMAT ultrasonic longitudinal wave resonance method for wall thickness measurement at high temperatures

In this paper we propose a novel ultrasonic longitudinal wave resonance method for measuring the thickness of metal walls using a laser-electromagnetic acoustic transducer (Laser-EMAT). The method is based on the surface constraint mechanism (SCM) of the material and is expected to be capable of accurately detecting local thinning of metal walls in a non-contact manner and at high temperatures. Based on finite element analysis of laser-EMAT ultrasonic resonance measurement of aluminum alloy thickness, we investigated the effects of such key factors as SCM, irradiation parameters of laser source, and the size of EMAT receiving coil on the accuracy of thickness measurement (resonance frequency position) and on the amplitude of the resonance wave. Both numerical simulations and experiments are conducted to demonstrate that the measurement accuracy of the proposed method is not affected by SCM, irradiation laser source parameters, and EMAT receiving coil size, and that accurate detection of stepped aluminum plates with thickness thinning from 3.0 mm to 0.5 mm is achieved. Furthermore, we were able to perform rapid detection of aluminum thin plate thickness at 500 °C temperature with an EMAT lift-off of 5.0 mm and achieved a relative experimental error as small as 3.40 %. The results obtained in this study showed that the proposed method performed well in non-contact measurement of metal thinning in harsh environment of high temperature.

High precision ultrasonic measurement method for thin-walled parts

Thin-walled parts are extensively utilized in the aerospace industry, where over thinning defects in these parts would significantly compromise mechanical safety. Ultrasound measurement methods are commonly employed for thickness non-destructive testing. Manual calibration of reference signals is usually necessary, negatively impacting automation, robustness, and accuracy. This paper proposes a high-precision ultrasound amplitude method for thin-walled component inspection, getting rid of manual calibration. Firstly, the measured signal is preprocessed to extract the spectrum in the effective frequency range. Then, the spectrum is approximated using the asymmetrical Gaussian amplitude model to estimate the spectrum of reference signal and reflection coefficient. Moreover, initial propagation time is estimated from autocorrelation of the signal. Finally, the accurate thickness is obtained from the numerical calculation of reflection coefficient with the initial time. Simulations and experiments demonstrate that the proposed method can accurately measures metal plates as thin as 0.5 mm. Compared to the traditional correlation method, it greatly improves measurement accuracy and stability, reducing them to 1/2 and 1/4 of the latter, respectively. Additionally, the proposed method also demonstrates high accuracy for curved thin plates, with an average relative error of only 0.57 %. Furthermore, the method exhibits high levels of automation, robustness, and accuracy, and holds significant potential for thickness detection in thin-walled structural components.

Phased Array Ultrasonic Method for Robotic Preload Measurement in Offshore Wind Turbine Bolted Connections.

This paper presents a novel approach for preload measurement of bolted connections, specifically tailored for offshore wind applications. The proposed method combines robotics, Phased Array Ultrasonic Testing (PAUT), nonlinear acoustoelasticity, and Finite Element Analysis (FEA). Acceptable defects, below a pre-defined size, are shown to have an impact on preload measurement, and therefore conducting simultaneous defect detection and preload measurement is discussed in this paper. The study demonstrates that even slight changes in the orientation of the ultrasonic transducer, the non-automated approach, can introduce a significant error of up to 140 MPa in bolt stress measurement and therefore a robotic approach is employed to achieve consistent and accurate measurements. Additionally, the study emphasises the significance of considering average preload for comparison with ultrasonic data, which is achieved through FEA simulations. The advantages of the proposed robotic PAUT method over single-element approaches are discussed, including the incorporation of nonlinearity, simultaneous defect detection and stress measurement, hardware and software adaptability, and notably, a substantial improvement in measurement accuracy. Based on the findings, the paper strongly recommends the adoption of the robotic PAUT approach for preload measurement, whilst acknowledging the required investment in hardware, software, and skilled personnel.

Experimental investigation on the measurement performance of high-speed ultrasonic wave thermometry in ambient- and high-temperature environments

This study proposes a high-speed (∼500 Hz), non-intrusive ultrasonic-based temperature measurement method and investigate its performance characteristics by conducting a static behavior measurement at ambient temperature and a dynamic behavior measurement from ambient temperature to 700 °C. In the ambient-temperature experiment, the optimal design of the ultrasonic wave propagation tube is verified by comparing the collected signal intensities. The high repeatability of the ultrasonic wave measurement method is verified with Pearson correlation coefficients of over 99.96 % among the received raw ultrasonic wave signals for every 0.002 s. In the dynamic high-temperature experiment, the measurement accuracy is validated by comparing the temperature deviation from the thermocouple temperature. In the fast-rising low-temperature region around 25–100 °C, a high error rate (>100 %) is obtained; therefore, a signal-denoising algorithm and four candidates of post-processing equations are applied to improve the ultrasonic wave thermometry accuracy. In the four candidate equations, the optimal post-processing method is determined to be the one that yields a linear fitting with slope and intercept obtained in Kelvin temperature. The accuracy of ultrasonic wave thermometry is verified with the time-weighted average and standard deviation of error rates being 1.09 % and 1.10 %, respectively, significantly lower than those of typical commercial thermocouples. As ultrasonic wave thermometry can only perform line-integral measurement and not point measurement, it can be effective for anomaly detection of steady operating systems like gas turbines and boilers for power generation. Thus, fast-responsive, line-integral ultrasonic wave thermometry can be a diagnostic tool to reduce the risk of combustion instability accidents or other problems caused by rapid temperature change.

Comparative Analysis of Ultrasonic and Traditional Gas-Leak Detection Systems in the Process Industries: A Monte Carlo Approach

Gas leaks can cause disasters at process sites, including fires and explosions, and thus, effective gas-leak detection systems are required. This study investigated the limitations of conventional detectors and introduced an innovative ultrasonic sensor-based approach for continuous monitoring. A new configuration for a stationary remote ultrasonic gas-leak monitoring system is proposed. The selected material was 1-Butene. The detection probability was assessed through a simulation based on a gas-leak scenario, detailing the selection criteria for leak sites and simulation conditions. Computational fluid-dynamics (CFD) simulations were used to evaluate the detection capability of the existing system, whereas Monte Carlo simulations were used to compare it with the proposed ultrasonic system. The CFD simulation was performed by setting the lower detection limit of the concentration-measurement-type gas detector to 600 ppm, and the leak-detection time was approximately 8.895 s. A Monte Carlo simulation accounting for wind direction showed that the existing system’s average detection probability was 3.41%. By integrating the existing and new systems, the detection probability increased by 96.58% and 3.92% compared with that using only the concentration-measurement and ultrasonic measurement methods, respectively. These rates provide valuable insights for future applications in oil refining and petrochemical industries.

Проблематика оценки глубины асфальтосмолопарафиновых отложений в трубных системах транспортирования нефти

During the operation of oil pipelines, an accumulation of asphalt-resin-paraffin deposits is observed on their inner surface, which significantly reduce the efficiency of their operation. These deposits are a significant obstacle to the activities of oil transportation industries. There are permanently significant funds for the cleaning of oil pipelines of the given negative accumulations. In order to determine the prospects and effective implementation of high-cost treatment measures, there is a need for adequate data on the current thickness of deposits in pipelines. This article compactly presents measuring instruments based on radiation, ultrasonic, dielkometric and thermal measurement methods. At the same time, the main requirement for such measuring instruments is metrological reliability, provided through their intellectualization, in other words, providing them with parameters that make it possible to function under conditions of significant uncertainty, failures and a number of subsystems, which is provided by redundancy. Essential requirements are the safety of operation and ease of operation. The most reliable method of measuring the height of the deposits under study now is an ultrasonic method based on the emission of an ultrasound pulse through the pipeline wall and the registration of signals of their reflection from the opposite wall. The positive side of this approach is the possibility of placing a measuring device on the outer surface of the pipeline without destroying its integrity. The authors concluded that thermal and ultrasonic sensors are maximally suitable for solving these problems, the integration of signals from them makes it possible, in addition to reducing the error when measuring the height of deposits, to increase their reliability, as well as to maintain the survivability of the system in case of a malfunction or disconnection of any of the sensors.

Automatic Measurement of Contact Stress and Connection Force of Interference Components by Ultrasound

Tiny interference components play an important role in the aerospace and instrumentation fields. Contact stress and connection force are important factors in evaluating the reliability and service life of components. In this study, the ultrasonic method is used to measure the stress distribution and the connection force on the mating interface. Based on statistical microcontact theory, the virtual thin-layer model, and the asperity interaction model, the contact acoustic model is optimized. On this basis, the mapping relationship between contact stress and contact stiffness can be further obtained. This relationship was obtained by calibration experiments. Then, the stress distribution on the interface with two different structures, namely the uniform cylinder and the step cylinder, was measured and compared with the theoretical results of the thick-walled cylinder theory. The results show that the two have good consistency. Finally, based on the stress distribution, the connection force was calculated and compared with the experimental results. The results show that the ultrasonic measurement method can accurately measure the connection force, and the relative error is within 16%. Therefore, this study can provide a good method for the quality assessment of interference components.

Does endometrial compaction before embryo transfer affect pregnancy outcomes? a systematic review and meta-analysis.

There is no clear evidence of clinical significance of endometrial compaction, which can be measured by a reduction in endometrial thickness (EMT) during the follicular-luteal transition before the day of embryo transfer. In this study, we aim to determine whether endometrial compaction has an effect on in vitro fertilization (IVF) success. We searched PubMed, Cochrane, Embase, and Web of Science electronic databases for studies published in English up to March 2023. Heterogeneity between studies was assessed using the I2 statistic. The random effects model and fixed effects model was used to pool the risk ratio (RR) with a corresponding 95% confidence interval (CI). A subgroup analysis was performed based on different methods of ultrasonic measurement and different endometrial compaction rates (ECR). Stata 17.0 software was used for meta-analysis. Pregnancy outcomes, which included clinical pregnancy rate, ongoing pregnancy rate, live birth rate, and spontaneous abortion rate, were evaluated. In this study, 18 cohort studies were included, involving 16,164 embryo transfer cycles. Pooled results indicated that there was no significant difference between the endometrial compaction group and the non-compaction group in terms of clinical pregnancy rate (RR [95% CI]=0.98 [0.90,1.08]; I2=69.76%), ongoing pregnancy rate (RR [95% CI]=1.18 [0.95,1.47]; I2=78.77%), live birth rate (RR [95% CI]= 0.97 [0.92,1.02]; I2=0.00%) or spontaneous abortion rate (RR [95% CI]= 1.07[0.97,1.26]; I2=0.00%). According to the subgroup analysis of ultrasonic measurement methods, in the transvaginal ultrasound (TVUS) combined with abdominal ultrasonography (AUS) cycles of the endometrial compaction group, the rate of ongoing pregnancy (RR [95% CI] = 1.69 [1.26, 2.26]; I2=29.27%) and live birth (RR [95% CI] = 1.27 [1.00,1.61]; I2=62.28%) was significantly higher than that of the non-compaction group. Additionally, subgroup analysis based on ECR revealed a significantly higher rate of ongoing pregnancy when ECR ≥ 15% (RR [95% CI] = 1.99 [1.61, 2.47]; I2=0.00%). Endometrial compaction has no adverse effect on clinical pregnancy rate, ongoing pregnancy rate, live birth rate, or spontaneous abortion rate. A possible explanation for the contradictory findings of previous studies lies in the method by which the EMT is measured. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42023430511, identifier CRD42023430511.

Ultrasonic Thickness Measurement Method and System Implementation Based on Sampling Reconstruction and Phase Feature Extraction.

The existing ultrasonic thickness measurement systems require high sampling frequencies for echo signal acquisition, leading to complex circuit designs and high costs. Moreover, extracting the characteristics of ultrasonic echo signals for accurate thickness measurement poses significant challenges. To address these issues, this paper proposes a method that utilizes conventional sampling frequencies to acquire high-frequency ultrasonic echo signals, overcoming the limitations of high-frequency data acquisition imposed by the Nyquist-Shannon sampling theorem. By employing an improved sampling reconstruction technique, the multi-cycle sampling signals are reconstructed and rearranged within a single cycle, effectively increasing the equivalent sampling frequency. Additionally, a combination of coarse estimation using fast Fourier transform (FFT) and precise phase extraction using the moving sine fitting algorithm is proposed for accurate thickness measurement, resolving the limitations of common thickness measurement methods such as peak detection, envelope detection, and Hilbert autocorrelation in terms of low measurement accuracy. Experimental results obtained from thickness measurements on 45 steel ultrasonic test blocks within the range of 3 mm to 20 mm indicate a measurement error of ±0.01 mm, while for thicknesses ranging from 1 mm to 50 mm, the measurement error is ±0.05 mm.

Assessment of glycerol in biodiesel using an ultrasonic measurement method

Biodiesel is a renewable fuel, biodegradable and alternative to diesel oil consisting chemically of fatty acid alkyl esters and obtained by the transesterification reaction. After transesterification, undesirable components may remain in biodiesel. The presence of these components negatively influences the properties and performance of biodiesel. This research aims to evaluate biodiesel quality, using the quantitative ultrasound technique to determine the presence of the contaminant glycerol in biodiesel samples. The blends used in this study consisted of biodiesel and glycerol varying from 0 % to 0.5 % of glycerol by mass. The measurement uncertainty was evaluated according to the Guide to the Expression of Uncertainty in Measurement. The speed of sound in biodiesel/glycerol blends was measured by the pulse-echo technique (@ 5 MHz) and was considered equivalent for the different concentrations studied. The maximum measurement uncertainty obtained was 2.2 m·s−1 (0.16 %).

Stress measurement of aero-engine thin-walled catheter based on ultrasonic guided wave.

A pipeline system made of catheters is used for liquid-gas transportation in aero-engines. It is important to measure the residual stresses, such as the assembly stress in this system, as they influence performance and lifetime. Compared to other testing techniques, ultrasonic measurement methods based on acoustic-elastic effects can better solve problems. For the above requirements, this paper researches an aero-engine thin-wall catheter's assembly stress measurement method based on ultrasonic guided waves's acoustic, elastic effect. The propagation and dispersion characteristics of guided ultrasonic waves in the catheter were studied. Then, the excitation frequency, guided wave mode, and single-mode excitation mode of the simulation model were determined. Next, a finite element simulation model was established for simulation experiments. In order to reduce the influence of sampling rate and working environment noise on the measurement accuracy of assembly stress, the ultrasonic guided wave signal was processed by the wavelet threshold method. A good noise reduction effect was obtained by determining the wavelet base and the number of decomposition layers. Finally, an experimental platform was built to measure the assembly stress of thin-walled catheters. The maximum measurement error of the assembly stress of a thin-walled catheter was 21.1 MPa, which verified the feasibility of the measurement method. This study provides a promising method for accurately measuring the assembly stress of thin-walled catheters in aero-engines.

A refined energy ratio method based on ultrasonic echoes for measuring short bolt axial stress

Ultrasonic stress measurement methods play an important role in measuring bolt axial stresses. Traditional Time of Flight (TOF) approaches have accuracy limits when applied to short-bolt stress measurement. This paper proposes a Refined Ultrasonic Echo-based Energy Ratio (RUEER) method for bolt stress measurement that considers internal nonlinear scattering attenuation effects, transmission-reflection effects at the interface area, and energy loss in the transition region. The ultrasonic wave inside the stressed bolt is decomposed into different components to better evaluate the energy attenuation of ultrasonic echoes. The proposed method is verified with stress measurement experiments. Results show that the average error of the proposed RUEER method is less than 2.5% for different bolts and clamping lengths. Through comparative testing, the accuracy of the proposed method demonstrates improved performance over the TOF and Energy Attenuation Method (EAM). Additionally, the RUEER method is more robust to variations in equipment performance than the TOF method.

Assessment of Occupational Risk in the Case of the Ultrasonic Noise Exposure

Increased efficiency of production and improved quality have contributed to the development of ultrasonic technological applications, in which low frequency ultrasounds are generated to operate, accelerate as well as to facilitate technological processes. Technological ultrasonic devices (i.e. sources of ultrasonic noise in the work environment, e.g. ultrasonic washers, ultrasonic welding machines) have relatively high power and their nominal frequencies are in the range from 18 kHz to 40 kHz. In Poland, ultrasonic noise (defined as noise containing high audible and low ultrasonic frequencies from 10 kHz to 40 kHz) is included in the list of factors harmful to health in the work environment and therefore the admissible values of ultrasonic noise in the workplaces are established. The admissible values of ultrasonic noise and the new ultrasonic noise measurement method make it possible to perform the assessment of occupational risk related to ultrasonic noise. According to this method, the scope of the measurements includes the determination of the equivalent sound pressure levels in the 1/3 octave bands with the centre frequencies from 10 kHz to 40 kHz. This paper presents the description of both, i.e. the method for ultrasonic noise measurements and the method of the assessment of occupational risk related to ultrasonic noise. The examples of the results of the assessment of occupational risk related to exposure to ultrasonic noise are also discussed.

Measurement of Air Layer Thickness under Multi-Angle Incidence Conditions Based on Ultrasonic Resonance Reflection Theory for Flange Fasteners

During the servicing of flange fasteners, the sealing gasket and the flange cover interface are prone to separation and air contamination due to factors such as stress, corrosion, and vibration. In the detection process, there are two main issues: firstly, the conventional ultrasonic measurement methods based on the theory of acoustic elasticity are not applicable due to the small thickness of the air layer; secondly, the use of conventional vertical incidence detection methods is difficult to ensure due to the influence of the actual structure. To address these issues, this paper first establishes a mathematical model of ultrasonic resonance reflection, and then calculates the corresponding relationship between the air layer thickness and the resonance frequency under vertical incidence conditions. However, this model is difficult to use to calculate the resonance frequency under different incidence angles. To meet the requirements of different working conditions, a finite element simulation model is further established. By comparing the calculation results of the two models under vertical incidence, the reliability of the established finite element model is verified. The reflection and transmission pressure acoustic field distribution under different incidence angles and air layer thicknesses is simulated, and the function relationship between the incidence angle, air layer thickness, and the corresponding first-order resonance frequency is derived. This enables the measurement of the air layer thickness at any incidence angle, providing technical and theoretical support for practical industrial applications.

Ultrasonic Wave Mode-Based Application for Contactless Density Measurement of Highly Aerated Batters.

An ultrasonic wave mode-based method for density measurement in highly foamed batters was developed. Therefore, a non-contact ultrasonic sensor system was designed to generate signals for batch-wise processes. An ultrasonic sensor, containing a piezoelectric ceramic at the fundamental longitudinal frequency of 2 MHz, was used to take impedance measurements in pulse-echo mode. The ultrasonic signals were processed and analysed wave-mode wise, using a feature-driven approach. The measurements were carried out for different mixing times within a container, with the attached ultrasonic sensor. Within the biscuit batter, the change to the ultrasonic signals caused by density changes during the batter-mixing process was monitored (R2 = 0.96). The density range detected by the sensor ranges between 500 g/L and 1000 g/L. The ultrasonic sensor system developed also shows a reasonable level of accuracy for the measurements of biscuit batter variations (R2 > 0.94). The main benefit of this novel technique, which comprises multiple wave modes for signal features and combines these features with the relevant process parameters, leads to a more robust system as regards to multiple interference factors.