Electromagnetic Flow Sensor Research Articles

Review and Analysis of the Characteristics of IoT Sensors

Internet of things (IoT) is the concept of data transmission network between physical objects ("things"), equipped with built-in tools and technologies for interaction with each other or with the environment. The work is devoted to the inspection and analysis of sensors, how the IoT systems are associated with environmental objects. IOT uses a wide class of measurement tools, from elementary sensors (eg, temperature, pressure, light), consumption metering devices (such as intellectual meters) to complex integrated measuring systems. The parameters of 30 types of sensors for IoT are given, 2 of them of the type of temperature and humidity sensors, 2 type of pressure sensors, 13 sensors that measure the flow and amount of gas or liquid, 2 type of accelerometers, 10 approach and movement sensors and 1 noise sensor. Among them are 4 sensors for wireless sensory networks (WSM), a single-time medical sensor for internal blood pressure measurement, calorimetric, vortex and electromagnetic flow sensors and gas or fluid, accelerometer, and memes of memes, and e-memometers, and electromagnetic measurement motion, a device of measuring noise level in the range of sound vibrations. For some sensors, there are no metrological characteristics at all, at best there is only a range of measurements and resolution. The resolution ranges from 8 bits to 16 bits with a signal sampling rate from 0.5 Hz to 48 kHz. There is even a LDC1612 digital induction chip with 28 bits. WSM sensors are designed to work with DigiMesh, LoraWan and Arduino, Raspberry. Many sensors use outdated RS 232, RS 432, I2C. Keywords: internet of things, network, review, analysis, sensors, objects, metrology.

Optimization of electromagnetic flow measurement system based on a new mesh electrode

Electromagnetic flowmeter(EMF) is a common volumetric flow measurement instrument widely used in industrial flow measurement. With the development of EMF in the direction of high precision and intelligence, it is increasingly urgent to further improve the accuracy of EMF measurement. The key to reducing measurement error and eliminating the impact of interference noise is optimizing the electromagnetic flow sensor structure. Aiming at the existing EMF electrode optimization deficiencies, a new mesh structure electrode is firstly proposed in this paper. Then, a theoretical study on the distribution of virtual current density based on this mesh structure electrode is carried out, different structure electrodes are verified and analyzed through COMSOL finite element simulation, and the optimal structure design parameters of the new mesh electrode are obtained. Finally, an experimental platform is built, and a comparative experiment is conducted on the electromagnetic flow measurement system composed of the new mesh structure electrodes. The experimental results show that the maximum relative error of the optimized electromagnetic flow measurement system (OEMFS) is reduced by 0.47% compared with the ordinary EMF in the non-axisymmetric flow test. In the low-flow velocity test, the maximum relative error of the OEMFS is reduced by 7.46% compared with the ordinary EMF. In the strong interference test, the steady-state fluctuation of the amplitude of the OEMFS is reduced by 5.01% compared with the ordinary EMF. The OEMFS has better anti-interference, and the relative error of the system is less affected by the change in flow rate.

Electromagnetic Flowmeter for Rapid Metering of Microfluidics Based on an Ag/AgCl/Porous Graphite Electrode Sensor.

The imposed interference by the signal electrodes limits the expansion of the measurement range in electromagnetic flow sensors (EFS). This is because the interference makes it difficult to increase the signal-to-noise ratio in the state of the microfluid. In this paper, an Ag/AgCl/porous graphite electrode sensor is successfully prepared by a chemical vapor deposition (CVD) method. This enables a high-reliability and wide measurement range surveillance system, which is also maintenance-free and cost-effective and has a long lifetime. AgCl is facilely synthesized by a mild method, and our analysis and experiments show that as-prepared AgCl nanoparticles demonstrate a high crystalline level and high quality. Further system testing and experiments are also conducted on EFS in cases where the Ag/AgCl/porous graphite electrode sensor is set as the core. It is seen that, within the flow range of 0.003-4 m3/h, the induced electromotive force is linearly related to the flow rate of the fluid. The measurement accuracy of the EFS using the transient measurement method is below 1%, and its sensitivity is not affected by the fluid temperature.

A study on structure improvement scheme of electromagnetic flow sensor for slurry flow measurement

A scheme to improve the structure of electromagnetic flow sensor is put forward in this paper, which can effectively solve the slurry noise problem when electromagnetic flowmeter measures slurry fluid. The electromagnetic flow sensor used for measuring slurry fluid has slurry noise interference in the measurement signal. At present, the method of increasing the excitation frequency of electromagnetic flow sensor is widely used to overcome slurry noise. However, high excitation frequency will lead to poor stability of zero point. In view of the shortcomings of existing methods, this paper studies the method of improving sensor structure to overcome slurry noise. Firstly, according to the mechanism of slurry noise, an improved scheme for the installation position of the measuring electrode of electromagnetic flow sensor is proposed, which can greatly reduce the probability of solid particles of slurry fluid colliding with the measuring electrode; Then, the relevant research results of bubble dynamics theory are applied to optimize the improvement scheme, and the improvement scheme is determined, through calibration, it is concluded that the improved sensor can reach the accuracy level of 1.0; Finally, through slurry measurement experiments, it is verified that the improved electromagnetic flow sensor can effectively overcome slurry noise.

A Combined Numerical-Experimental Study on the Noise Power Spectrum Produced by an Electromagnetic Sensor for Slurry Flow

The signals generated by electromagnetic flow sensors used for slurry fluids are often affected by noise interference produced by interaction with the slurry itself. In this study, the power spectrum characteristics of the signal are studied, and an attempt is made to determine the relationship between the characteristics of the related noise and the velocity and concentration of the slurry fluid. Dedicated experiments are conducted and the related power spectrum curve is obtained processing the signal measured by the sensor with Matlab. Numerical simulations are also carried out in the frame of an Eulerian approach in order get additional insights into the considered problem through comparison with the experimental results. The following conclusions are drawn: (1) The intensity of noise is directly proportional to the number of solid particles colliding with the electrode of the electromagnetic flow sensor per unit time, and to the square of the average velocity of the flow layer near the pipe wall. (2) With an increase in the slurry noise intensity, the power spectrum curve shifts upward in the logarithmic coordinate system (and vice versa).

An Improved Electromagnetic Flowmeter

Electromagnetic flowmeters are widely used in industrial production or control. However, the structure of the traditional electromagnetic flowmeter makes it restricted in some applications. With the development of medicine, aviation and other fields, people’s demand for multiphase flow measurement is increasing. However, the theoretical study of the multi-electrode electromagnetic flowmeter has always lacked systemicity, especially in the relationship between the tube wall, the electrical characteristics of the fluid and the output signal. Based on the existing research, this paper studies several key technologies of multi-electrode electromagnetic flowmeter. The structure of the existing electromagnetic flowmeter is improved, and a multi electrode non insulated pipe wall electromagnetic flow sensor is proposed. According to the equivalent circuit, the influence of the sensor structure on the measurement is analyzed, and the disturbance of the electrical characteristics of the tube wall to the output signal is obtained by combining with the weight function analysis. According to the results of theoretical calculation and analysis, a negative feedback circuit is designed. According to the experimental results, the accuracy and reliability of the novel electromagnetic flowmeter are verified.

The Study of Conductive Inner Lining of the Electromagnetic Flowmeter (EMF) on the Output

The lining of traditional electromagnetic flow sensor is insulated. But this limits the use of electromagnetic flowmeter. This paper presents a new type of electromagnetic flowmeter, which can measure the conductivity of pipe wall. The circuit is designed to compensate the sensor output induced potential. The stability and reliability of the new electromagnetic flowmeter are verified in theory and experiment.

Study on measurement error of iron ore pipeline transportation flow based on weight function theory of electromagnetic flow sensor

An electromagnetic flow sensor applied to the flow measurement of iron ore pipeline transportation will incur a measurement error after being used for a period of time, and the error will increase continuously. In this paper, based on the weight function theory of electromagnetic flow sensors, the main cause of the error is proposed. Specifically, in the process of using the electromagnetic flow meter the insulation lining of the sensor is easily damaged because the measuring pipe of the sensor constantly collides with the solid phase of the fluid, leading to a change in the distribution of the weight function of the electromagnetic flow sensor, which, in turn, changes the contribution of the induced electromotive force generated by each medium in the pipe to the measuring electrode. This paper is based on the PDE computer numerical calculation method, and, according to the analysis of the weight function under different boundary conditions, the rule that the output signal of the electromagnetic flow sensor decreases with increasing insulation lining area is obtained. The computer numerical calculation method used in this paper can provide a new approach to the theoretical analysis of the weight function of electromagnetic flow sensors. Furthermore, the conclusion reached in this paper can provide a theoretical basis for the development and maintenance of electromagnetic flow sensors applied to the flow measurement of iron ore pipelines.

Performance Differences of an Electromagnetic Flow Sensor With Nonideal Electrodes Based on Different-Dimensional Weight Functions

In the strict sense, the electrodes of the electromagnetic flow sensor (EFS) are nonideal, and the selection of models with different dimensions can result in a relatively large difference in the calculation of the weight function, which further affects the estimation of the output signal. The aim of this paper is to explore the difference in the characteristics of the 2-D and 3-D EFSs with nonideal electrodes. In this paper, the analytical expressions of weight function for both 2-D and 3-D cases are deduced mathematically, and a general weight function methodology based on simulation data and fitting is presented to solve the mixed boundary problem. The effectiveness of the proposed method is verified by the comparison with the numerical simulation. Meanwhile, the distributions of weight function for 3-D EFSs with different electrodes in cross sections are obtained by means of the method mentioned above, and the difference between the 2-D model and the 3-D model is revealed intuitively. Finally, the output characteristics of the EFS with different dimensions and electrode shapes are calculated by coupling the data of three fields, including the weight field, the flow field, and the magnetic field. Based on the comparison between the experimental data and the calculated values, the direct influence of the dimension and the electrode shape on the output characteristics of the EFS is discussed, and the theoretical analysis is made for the structure design and optimization of the EFS.

Quantitative assessment of paravalvular leakage after transcatheter aortic valve replacement using a patient-specific pulsatile flow model

BackgroundQuantitative assessment of post-transcatheter aortic valve replacement (TAVR) aortic regurgitation (AR) remains challenging. We developed patient-specific anatomical models with pulsatile flow circuit and investigated factors associated with AR after TAVR. MethodsBased on pre-procedural computed tomography (CT) data of the six patients who underwent transfemoral TAVR using a 23-mm SAPIEN XT, anatomically and mechanically equivalent aortic valve models were developed. Forward flow and heart rate of each patient in two days after TAVR were duplicated under mean aortic pressure of 80mmHg. Paravalvular leakage (PVL) volume in basal and additional conditions was measured for each model using an electromagnetic flow sensor. Incompletely apposed tract between the transcatheter and aortic valves was examined using a micro-CT. ResultsPVL volume in each patient-specific model was consistent with each patient's PVL grade, and was affected by hemodynamic conditions. PVL and total regurgitation volume increased with the mean aortic pressure, whereas closing volume did not change. In contrast, closing volume increased proportionately with heart rate, but PVL did not change. The minimal cross-sectional gap had a positive correlation with the PVL volumes (r=0.89, P=0.02). The gap areas typically occurred in the vicinity of the bulky calcified nodules under the native commissure. ConclusionsPVL volume, which could be affected by hemodynamic conditions, was significantly associated with the minimal cross-sectional gap area between the aortic annulus and the stent frame. These data may improve our understanding of the mechanism of the occurrence of post-TAVR PVL.

W052003 流れを視る医療用・バイオ用ディスポーザブル型流量計

Regarding Aichi Tokei Denki' s electromagnetic flow sensor which has such disposable structure that its flow-pass portion in contact with liquid can be replaced easily, the resin molding and the bonding technology to construct two flow-passes in the disposal flow-pass chip with high precision are described. Furthermore, the two flow-passes of the disposal flow-pass chip can measure different fluids in different flow-rates. The electromagnetic flow sensor of disposable structure is able to cope with various applications, as replacement of the disposable flow-pass chip can easily be done by any nurse and engineer, because knowledge of flow measurement is not required for the replacement.

Įrengimo sąlygų įtaka srauto matuoklių metrologinėms charakteristikoms

Darbe nagrinėjama įrengimo sąlygų įtaka elektromagnetinių ir turbininių srauto matuoklių metrologinėms charakteristikoms. Buvo tyrinėti vienodo vardinio skersmens (DN50) matuokliai esant 0,5–50 m3/h debitų diapazonui. Matavimai buvo atlikti, skaitiklius iš abiejų pusių prijungus vadinamaisiais standartiniais vamzdžiais (Dvid = 50,5 mm) – padidinto (55,2 mm) ir sumažinto (46,2 mm) skersmens. Be to, buvo tiriama tarpinių kiaurymės ( ∅ 50, ∅ 45 ir ∅ 40) įtaka. Matavimai parodė, kad turbininis srauto matuoklis jautriausiai reaguoja sumažinus tiek vamzdžio skersmenį, tiek ir tarpinę kiaurymę, o papildoma paklaida dėl skersmens sumažinimo gali padidėti net iki 25 %.

No major role of BKCa channels in the modulation of renal blood flow in rats

The aim of the present study was to investigate the role of large calcium activated potassium (BKCa) channels in the maintenance of basal renal vascular tone in vivo in anesthetized adult Sprague-Dawley rats. We also examined whether the vasoconstriction elicited by angiotensin II (Ang II) and norepinephrine (NE) was buffered by simultaneous activation of BKCa. Vasoactive agents, BKCa blockers or a stimulator were infused directly into the renal artery via a polyethylene (PE-10) catheter introduced into the left femoral artery and advanced through the abdominal aorta and approximately 1 mm into the left renal artery. Renal blood flow (RBF) was measured by using an electromagnetic flow sensor. Renal preinfusion of BKCa blockers tetraethylammonium chlorid (TEA) (3.0 μmol/min) for 1 (n = 8) or 5 min (n = 5) and iberiotoxin for 5 min (n = 6) (3.3 nmol/min) did not significantly affect the RBF baseline. Renal arterial injection of a 10 μL bolus of Ang II (n = 18) (1-4 ng/10 μL) or NE (n = 17) (10-40 ng/10 μL) produced a significant dose dependent temporary decrease in RBF. These responses were not significantly affected by 1 or 4 min preinfusion of TEA (n = 8) or a 4 min preinfusion of iberiotoxin (n = 6). Renal addition of the BKCa opener NS 1619 (n = 5) (30 and 90 μmol/min) did not significantly affect basal renal blood flow or the responses to Ang II and NE. The present results do not indicate any major role for BKCa channels in the control of basal renal tone in vivo. Furthermore, there is no support for the hypothesis that BKCa channels have a buffering effect on the responses to Ang II and NE in rat renal vasculature. (Supported by Danish Heart Foundation)

SENSORLESS ESTIMATION OF FLOW AND PRESSURE HEAD IN AN UNDULATION PUMP WITH PULSATILE DRIVEN

It is essential to measure pump flow and pressure to control the artificial heart. Although, the pump flow and pressure can be measured by electromagnetic flow sensor and semiconductor pressure sensor respectively, these methods have disadvantages due to its large size, poor stability, and anti-thrombogenicity. We have developed an undulation pump that can produce pulsatile flow by modulating its motor rotational speed. In our previous study, we have established a method to measure steady flow and pressure head, derived from the motor current and motor rotational speed. However, this method cannot be applied to pulsatile flow. In the present study, we developed a new method to measure pump flow and pressure head for pulsatile flow patterns. We have established an experimental formula in which the pressure head is derived from the angler speed and acceleration of the motor shaft, and motor current, pump flow be estimated from this pressure head and the motor rotational speed. The estimation pump flow and pressure head using this method, was compared with the actual value as measured by sensors. In an in vitro experiment, the mean error between this method and sensor were 0.23Umim for pump flow, 8.5mmHg for pressure head. In an in vivo experiment of total artificial heart in a goat, the mean error between these two methods were 0.87L/min for pump flow, 15.8mmHg for pressure head. These results show that this method has enough accuracy to measure the pump flow and pressure head for pulsatile flow.

SENSORLESS MEASUREMENT OF PULSATILE PUMP FLOW AND PRESSURE HEAD IN AN UNDULATION PUMP

It is essential to measure pump flow and pressure to control the artificial heart. Although, the pump flow and pressure can be measured by electromagnetic flow sensor and semiconductor pressure sensor, these methods have disadvantages as its size, stability, and anti-thrombogenisity. We have developed an undulation pump that can produce pulsatile flow by modulating its motor rotational speed. In our previous study, we have established a method to estimate steady flow and pressure head, derived from the motor current and motor rotational speed. However, this method cannot be applied to pulsatile flow. In the present study, we developed a new method to estimate pump flow and pressure head for pulsatile flow. We have established an experimental formula in which the pressure head is derived from the angler speed and acceleration of the motor shaft, and motor current. Pump flow can be estimated from this pressure head and the motor rotational speed. The estimation pump flow and pressure head using this method, were compared with the actual value as measured by sensors. In an in vitro experiment, the mean error between this method and sensor were 0.23L/mim for pump flow, 8.5mmHg for pressure head. In an in vivo experiment of total artificial heart in a goat, the mean error between these two methods were 0.87L/min for pump flow, 12.8mmHg for pressure head. These results show that this method has enough accuracy to estimate the pump flow and pressure head for pulsatile flow.

Differential effects of sulindac on renal hemodynamics and function in the rat

Renal hemodynamics were studied using an electromagnetic perivascular flow sensor in anesthetized rats injected i.v. with vehicle, 5 or 10 mg/kg body weight (b.w.) sulindac. No hemodynamic changes occurred with vehicle ( n=6), but mean arterial pressure was significantly decreased (by 15 mmHg) with sulindac ( n=12). In the 5 mg/kg b.w. sulindac group ( n=7), renal blood flow progressively and significantly increased from 7.88±0.36 to 8.98±0.58 ml/min, except during concomitant intrarenal infusion of 3 mg/kg b.w. per h proadifen ( n=7). The pressure limits for efficient and no renal blood flow autoregulation remained unchanged (approx. 100 and 80 mmHg, respectively). In the 10 mg/kg b.w. sulindac group ( n=5), renal blood flow did not change but autoregulatory pressure limits were lowered by 10 mmHg 2 h after treatment ( P<0.025). Also, Na + retention was marked. Prostanoid excretion in urine was significantly reduced with either dose but basal plasma renin activity was not (about 8 ng/ml per h; n=15). When plasma renin activity was enhanced after a reduction in renal perfusion pressure ( n=21), it was decreased from 11.5±1.2 to 7.4±0.2 ng/ml per h only by 10 mg/kg b.w. sulindac ( P<0.05; n=6). In conclusion, differential effects of sulindac on renal hemodynamics, Na + excretion and plasma renin activity were demonstrated. Renal hemodynamic changes could be related in part to the cytochrome P-450 arachidonic acid pathway.

Measurement of blood flow rates in the lower extremities with use of a nuclear magnetic resonance based instrument

Direct, noninvasive measurement of pulsatile blood flow to the human extremity is now possible by means of a flow measurement instrument that is based on the principles of nuclear magnetic resonance. The instrument uses a physically independent calibration module as a primary calibration standard. Volumetric calibration of this module indicates that it is precise and accurate over the range of 0 to 100 ml/min. The calibration module is used, in turn, to calibrate an electromagnetic flow sensor that is incorporated into the instrumentation. The calibration module and the electromagnetic sensor were found to be linearly related over the range of 5 to 100 ml/min, with a regression correlation coefficient of 0.996. The calibrated electromagnetic flow sensor is used as a secondary standard for calibration of the nuclear magnetic resonance sensor. Blood flow measurements, obtained by use of this method, agree closely with those obtained by plethysmographic methods. They differ from the plethysmographic results in that magnetic resonance flows will distinguish between the at-rest blood flow in the normal extremity and the flows seen in the extremity (also at rest) with claudication. Based on the results obtained from studying a limited number of limbs with a high degree of ischemia, the method will not distinguish the limb with ischemia from the limb with claudication. Limitations of the method and refinements required to make the method clinically useful are discussed.

Measurement of blood flow rates in the lower extremities with use of a nuclear magnetic resonance based instrument

Direct, noninvasive measurement of pulsatile blood flow to the human extremity is now possible by means of a flow measurement instrument that is based on the principles of nuclear magnetic resonance. The instrument uses a physically independent calibration module as a primary calibration standard. Volumetric calibration of this module indicates that it is precise and accurate over the range of 0 to 100 ml/min. The calibration module is used, in turn, to calibrate an electromagnetic flow sensor that is incorporated into the instrumentation. The calibration module and the electromagnetic sensor were found to be linearly related over the range of 5 to 100 ml/min, with a regression correlation coefficient of 0.996. The calibrated electromagnetic flow sensor is used as a secondary standard for calibration of the nuclear magnetic resonance sensor. Blood flow measurements, obtained by use of this method, agree closely with those obtained by plethysmographic methods. They differ from the plethysmographic results in that magnetic resonance flows will distinguish between the at-rest blood flow in the normal extremity and the flows seen in the extremity (also at rest) with claudication. Based on the results obtained from studying a limited number of limbs with a high degree of ischemia, the method will not distinguish the limb with ischemia from the limb with claudication. Limitations of the method and refinements required to make the method clinically useful are discussed.

Filtration of water from mother to conceptus via paths independent of fetal placental circulation in sheep.

1. Four pregnant ewes were operated on at 121-126 days of gestation. An electromagnetic flow sensor and an inflatable occluder were placed on the maternal common internal iliac artery. The ovarian arteries and veins were ligated. Indwelling catheters were placed in a maternal femoral artery and uterine vein and in the amniotic and allantoic fluids. An inflatable occluder was placed around the umbilical cord, close to the fetal abdomen. 2. Eight to nine days after surgery, the cord was occluded, the fetus killed and uterine blood flow reduced to one-quarter of its control value. The rate of water loss from the uterine circulation was calculated from blood flow and the venoarterial difference in blood osmolality. The amniotic and allantoic fluids were made hypertonic by infusion of 2 l into each sac of a solution of 1.5 mol of mannitol per litre of saline. The rate of water loss from the maternal uterine circulation was then measured five times over the next 4.5 h. 3. The combined filtration coefficient surface area product of the interfaces between maternal blood and the amniotic and allantoic sacs, normalized per kilogram fetal body weight, was (2.8 +/- 0.5) x 10(-6) cm3 s-1 kPa-1 kg-1 (mean +/- S.E.M).

Implantable sensor for intraoperative and postoperative monitoring of blood flow: A preliminary report

We have developed an implantable 20 MHz Doppler flow sensor, to monitor blood flow in patients after operation. During surgery the sensor is wrapped around a blood vessel and secured in place with a releasable tie. No tissue puncturing techniques are required. The lead wires, together with a release cable, are exteriorized through the chest wall. Several days after operation, the tie is externally released, and the sensor is pulled out. Twenty-seven sensors were implanted in 24 dogs for up to 16 days. All were extracted successfully with minimal visible behavioral reaction in the awake dogs and caused no thrombosis or vascular damage. The Doppler velocity signals had excellent linear correlations (r = 0.99) with data from electromagnetic flow sensors and timed blood collections. In addition, the sensors were applied to coronary artery bypass grafts in 31 patients for up to 2 days after operation. High-quality signals were obtained, and intraoperatively recorded signals agreed well with simultaneous electromagnetic flow tracings. All sensors were extracted with minimal discomfort to the awake patients and with no complications. Thus, the implantable flow sensor is a safe, reliable, accurate, and simple method for intraoperative and postoperative monitoring of blood flow in vessels 2.5 to 5 mm in diameter.