Ultrasonic sensor

In the ultrasonic caliper sub, two ultrasonic sensors are mounted 180° apart on stabilizer blades as shown in Figure 4-288. 

Intelligent vehicles have been developed with arrays of ultrasonic probes for pipeline inspection — one commercial version contains 512 ultrasonic sensors. 

Hinrichs and Thuen [28] used ultrasonic attenuation to determine the proper time for pressure application during an otherwise traditional pre-established cure cycle. Because dielectric is an electrical property, it is influenced by moisture content and temperature as well as viscosity, so it may vary quantitatively. Ultrasonic measurements are also affected by other parameters (i.e., void content), but they are a mechanical measurement rather than an electric one. The ultrasonic sensors used by Hinrichs unfortunately were less reliable than the dielectric sensors. 

A. Manetou, "Development of an ultrasonic sensor for monitoring air content", Leatherhead Food R.A. Research Report No. 667 (1990). 

In several renewable energy processes, including the concentrating solar collectors, boilers, and combustion systems, the accurate measurement and control of high temperatures are required. These (over 1,000°C) temperatures are most often detected by thermocouples (types B, C, R, and S) and by optical and IR-radiation pyrometers. These devices are only briefly mentioned here, because they will be discussed in detail later. Here, the emphasis will be on some of the other high-temperature detectors such as sonic and ultrasonic sensors. 

Figure 5 Using an ultrasonic sensor (reflection system)...

Asher, R.C. 1997. Ultrasonic Sensors for Chemical and Process Plants. Institute of Physics Publishing, Bristol. 

Garbolino et al. (65) studied the effects of shear rate on crystallization of a confectionery coating fat (hydrogenated and fractionated mixture of soybean and cottonseed oils) using ultrasonic sensors. They hypothesized that primary nucleation is less likely to be affected by shear and suggested that crystal nuclei probably form from heterogeneous nucleation sites (dust particles or other suspended insoluble materials and imperfections in the container walls). They also suggested that... 

The principles outlined in the above studies constitute the basics of ultrasonic measurements of fat crystallization. We now proceed to an investigation of the effect of changing model process conditions (shear rate) on fat ci stallization behavior. These studies are facilitated by the relative ease by which ultrasonic sensors could be applied to a processing operation. 

Ultrasonic methods are perhaps the best tools available for studying fat crystallization under certain circumstances. They surpass the precision available with NMR, yet the experimental operation is as simple and the equipment costs are lower. Uniquely, ultrasonic sensors can be readily applied on-line with little cost in precision and, particularly using the new reflectance approach, minimal modification of existing process equipment. 

Feed slurry is introduced into the basket through either single or multiple feed pipes, or by other means such as rotating feed cone to help distribute the solids on the basket wall. In most cases, feed slurry is introduced at an intermediate speed, although in some applications (FGD gypsum, for one), feeding is done at full speed. There are several methods available to control the feed and cake level such as mechanical, paddle-type feelers, capacitance probes, ultrasonic sensors, feed totalizer, or load cells. 

Another possibility is acoustic/ultrasonic sensors. We have not experimented with these, so we do not have any information to offer in this regard. 

Asher, R. C. Ultrasonic Sensors. Institute of Physics Publishing Bristol and Philadelphia, 1997. 

Ultrasonic sensors Attach to die Sound velocity, attenuation Low No... 

R.E. Dutton, and D.A. Stubbs, An ultrasonic sensor for high temperature materials, in Sensors and Modeling in Materials Processing Techniques and Applications, S. Viswanathan, R.G. Reddy, and J.C. Malas (eds.), The Minerals, Metals and Materials Society, 1997, pp. 295-303. 

The process must be close-loop controlled, using either rheological (MFM), infrared, or ultrasonic sensors. 

Ultrasonic sensor The reflection time of a high-frequency sound pulse can be measured to give an accurate estimate of distance from an object or from a liquid level. In the latter case, an ultrasonic sensor is a noncontact alternative to a float transducer. 

Designed to sort compacted bottles, the Poly-Sort system employs conveyors for singulation, and two devices for color and chemical composition identification. A vibratory conveyor singulates bottles a read conveyor transports bottles to an ultrasonic sensor that detects their position a near-infrared system detects the resin type a camera detects the color of the container a computer integrates data and makes an identification air jets divert bottles to the appropriate segregation conveyor or hopper. 

Means of inspection after draining have also been envisaged. These are probes equipped with ultrasonic sensor or fibroscope to ensure that no retention remains for a good carbonatation... 

Medium density can be measured on-line by acoustic methods. An ultrasonic sensor was installed in the autoclave and allowed on-line measuring of the speed of sound in the medium. An example is given in Fig. 5.11 for pure SCCO2. These values are compared with the NIST database and reveal an excellent agreement Knowing the speed of sound and pressure/temperature, it is possible to determine the medium density in the case of single or even multiple components. 

One of the main advantages of reaction calorimetry on the larger scale is the possibility of inserting into the reactor special analytical probes for on-line measurements. Some preliminary results obtained by coupling an ultrasonic sensor with calorimetry are presented in Fig. 5.17. The sensor is directly inserted into the reactor, its contribution in terms of heat accumulation having been previously determined so that the calorimetric signal is only related to the chemical reaction and process. At the moment, only the sound wave measurement is compared to the... 

Height relative to reference (laser, infrared or ultrasonic sensor)... 

One method of feeding material into an entry loop is by simply driving the payoff mandrel with an electric motor (see Fig. 11). Normally, this is accomplished with a DC motor, but on slow speed lines, an AC motor with an on-off -type operation may be adequate. When a DC motor is utilized, the loop position is usually automatically controlled with a set of photocells and flood lights or an ultrasonic sensor. This method of paying off material from the master coil is quite acceptable provided there are no stickers from the annealing furnace or any dents or damage to the sides of the coil. These defects would cause the material to stick to itself and not pay off with the force of gravity as it is uncoiled. 

Hauptmann P, Lucklum R, Puttmer A, and Banning B (1998) Ultrasonic sensors for process monitoring and chemical analysis State-of-the-art and trends. Sensors and Actuators A 67 32-48. 

Associated with refueling, inspection and maintenance (RIM) operations is the need for sensors. In addition to the traditional sensors used in other high-temperature reactors (thermocouples, ultrasonic sensors, etc ), liquid salts allow the use of optical systems. Salts are transparent between 200 and 2500 mn (50,000 to 4000 wave numbers). This includes the UV, visible, and near-infrared, with some transparency into the infrared from 2500 to 5000 nm (4000 to 2000 wave numbers). In other words, these salts are transparent over a wider range of the spectrum than is water. The liquid salt, depending upon its composition and activation, provides some radiation shielding for the optical systems. The coolant properties create new sensor options. 

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