As the working medium of machine, lubrication oil system is a very important component, which can be used to judge the operating conditions of machine, moreover, lubricating oil detection can eliminate the need for costly machine shutdowns for inspection. Metal particle is the most important parameter in lubrication oil detection. Inductance detection is one of the commonly used metal particle detection methods, with the development of micro fabrication technology, which can measure the sizes of metal particles and count the particles. In this paper, the model of ferromagnetic metal particle detection is established based on micro inductive sensor. It is obtained that the inductance change rate is proportional to the magnetic permeability of the metal particle and the cube of the particle size of metal particle. The tests about the metal particles with five different diameters are carried out, it is obtained that the theoretical values are in good agreement with the experimental values, the relative errors are less than 9.47%. And combined with experimental research, the magnetic permeability of ferromagnetic metal particles $\mu \,\,3.907\times 10^{4}$ H/m, $4.246\times 10^{4}$ H/m, $4.092\times 10^{4}$ H/m, $3.718\times 10^{4}$ H/m, $4.07\times 10^{4}$ H/m and $4.4289\times 10^{4}$ H/m is obtained when the radii of particles are $25~\mu \text{m}$ , $50~\mu \text{m}$ , $100~\mu \text{m}$ , $200~\mu \text{m}$ , $500~\mu \text{m}$ and 1 mm, the relative errors ${E}_{\text{r}}=\vert 1- \mu {/} \mu _{\text{AVG}} \vert $ are less than 8.82%.

Ferromagnetic Metal Particle Detection Including Calculation of Particle Magnetic Permeability Based on Micro Inductive Sensor

Embodiments relate generally to water meters and to systems and networks that contain such water meters. Particular water meters described herein are enabled for communication with a remote server to transmit flow measurement information. Some embodiments have a vibration sensor included in the water meter to sense vibration originating in the upstream water supply network that may indicate the possible presence of an upstream water leak.

Water meter and systems and networks comprising the same

Machine operating conditions can be obtained through lubrication oil detection; solid metal particles are the primary factor causing mechanical wear. The surface of the friction pair is usually specially treated with the nonferrous metal protective coating. Therefore, there are many kinds of nonferrous particles in the lubricating oil. In this paper, a method for measurement of nonferrous particles sizes independent of materials using the impedance signal of the inductive sensor is presented. Both the imaginary part and real part of the coil impedance signal are studied in this paper, which is different from traditional inductive sensor research only the imaginary part of impedance signal output is considered. Through theoretical analysis, it is found that the real and imaginary parts of coil impedance changes with different materials at the same size are corresponding to an elliptic function. Combining with the coil impedance measured in the experiment, the particle size can be obtained, which is independent of particle material.

A Method for Measurement of Nonferrous Particles Sizes in Lubricant Oil Independent of Materials Using Inductive Sensor

Ultrasonic flowmeter for measuring the flowrate of a fluid based on transit times of opposite propagating ultrasonic wave packets, including two ultrasonic transducers arranged at a flow tube for transmitting and receiving the ultrasonic wave packets through a fluid; a control circuit configured for operating the ultrasonic transducers to transmit and receive co-propagating and counter-propagating ultrasonic wave packets, and to determine transit times between transmission and reception of the ultrasonic wave packets; wherein the control circuit is further configured to continuously determine the flowrate of the fluid based on sequential application of separate flow measurement sequences and flow estimation sequences, the flow measurement sequence including transmitting and receiving a co-propagating wave packet and a counter-propagating wave packet, determining a transit time difference between the co-propagating and the counter-propagating wave packets, determining the speed of sound in the fluid, and calculating the flowrate based on the transit time difference and the speed of sound; and the flow estimation sequence including transmitting and receiving a co-propagating wave packet and/or a counter-propagating wave packet, and based on the co-propagating or the counter-propagating wave packet, determining whether a fluid condition of the fluid has changed since the previous flow measurement.

Ultrasonic flowmeter and method using partial flow measurements

This disclosure relates generally to detection of concentration of micro and nano particles in a fluid environment. An acoustic transmitter array is selective coated with polymer and receiver array is deployed at a random location in a conduit. The acoustic transmitter array on the conduit is insonified at a predetermined frequency to obtain a plurality of reflected signals. A plurality of key features pertinent to the conduit are extracted from the plurality of reflected signals to obtain a plurality of acoustic signals. A correlation model is configured by inputting, at least one feature associated with the pre-processed acoustic signals. A known concentrations of nano and micro particles are trained with an artificial neural network algorithm and calibrated with ground truth data. The location of the transmitter array and receiver array and the correlation model are finalized for detecting concentration of the particular micro and nano particles in the fluid environment.

System and method for detection of concentration of micro and nano particles in a fluid environment

A consumption meter, e.g. a water or heat meter, for measuring a flow rate of a fluid supplied in a flow tube. First and second ultrasonic transducers are arranged at the flow tube for transmitting and receiving ultrasonic signals transmitted through the fluid and operated by a flow measurement sub-circuit for generating a signal indicative of the flow rate of the fluid. A noise measurement sub-circuit operates a sensor arranged at the flow tube for detection of acoustic signals of the flow tube, and being arranged to generate a signal indicative of a noise level of the flow tube accordingly. This sensor may comprise a separate transducer, or the sensor may be constituted by one or both of the first and second ultrasonic transducers. The consumption meter may communicate data representative of the noise level via a communication module along with data consumed amount of water, heat etc. Such consumer noise level measurement at the consumer site allows collection of noise level data to assist in locating fluid leakages in a fluid supply pipe system.

Fluid consumption meter with noise sensor

A turbidity measurement device for measuring turbidity of a fluid flowing in a flow tube. A first transducer transmits ultrasonic signals through the fluid in the turbidity measurement section so as to provide a first ultrasonic standing wave between the first and second section ends. A receiver transducer receives the ultrasonic scattered response from particles in the fluid flowing through the turbidity measurement section. A control circuit operates the transducers and generates a signal indicative of the turbidity of the fluid in response to signals received from the receiver transducer. Preferably, the device may comprise a second transducer for generating a second ultrasonic standing wave with the same frequency, and further the two transducers may be used to generate a measure of flow rate by means of known ultrasonic techniques. This flow rate may be used in the calculation of a measure of turbidity. Both turbidity facilities and flow rate facilities may be integrated in a consumption meter, such as a heat meter or a water meter.

Turbidity sensor based on ultrasound measurements

A new highly sensitive ultrasonic sensor for the detection of particles in fluids is presented. The design differentiates from other methods by working on any fluid as the signal to detect is pressure waves, which allows for detection in optically opaque materials, such as oil, blood, and so on. The sensor is essentially maintenance free, and the low power consumption enables battery powered designs. The sensor provides true online measurements with a total measurement time well below 1 s. The detection limit as a function of particle size was investigated both theoretically and experimentally for polystyrene and silicon dioxide particles, and an excellent agreement was observed. An experimental detection limit that approaches 1 particle per mL for particle diameters above 20 $\mu \text{m}$ is observed. In comparison, the output of the ultrasonic sensor scales with optical turbidity for particles with a specific size. However, this scaling relation is different for different particle sizes, and for this reason, there is no universal relationship between the output of the ultrasonic sensor and optical turbidity.

An In-Line, High-Flowrate, and Maintenance Free Ultrasonic Sensor With a High Dynamic Range for Particle Monitoring in Fluids

Single particle detection by ultrasound scattering is demonstrated. Polystyrene particles with a diameter of 40 $\mu \text{m}$ are individually counted using a visual spectrogram method. As an alternative a less computationally expensive algorithm for the data analysis using Hilbert transform is also demonstrated. Experiments demonstrating the particle counting capabilities of the sensor for different flow rates and concentrations are shown and linear relationships are observed as expected. The sensor differs from other particle counters by handling high flow–rates (>800 L h−1) and having an extremely low detection limit of about 0.5 particles per mL in 1s, which is orders of magnitudes better than the ones for analogues optical particle sensors.

Jens Lykke Sørensen

Papers

Fluid consumption meter with noise sensor

Turbidity sensor based on ultrasound measurements

An In-Line, High-Flowrate, and Maintenance Free Ultrasonic Sensor With a High Dynamic Range for Particle Monitoring in Fluids

Ultrasonic flowmeter and method using partial flow measurements

High Flowrate and Low Detection Limit Single-Particle Ultrasonic Sensor