Ultrasonic probes components

In service inspections of French nuclear Pressure Water Reactor (PWR) vessels are carried out automatically in complete immersion from the inside by means of ultrasonic focused probes working in the pulse echo mode. Concern has been expressed about the capabilities of performing non destructive evaluation of the Outer Surface Defects (OSD), i.e. defects located in the vicinity of the outer surface of the inspected components. OSD are insonified by both a "direct" field that passes through the inner surface (water/steel) of the component containing the defect and a "secondary" field reflected from the outer surface. Consequently, the Bscan images, containing the signatures of such defects, are complicated and their interpretation is a difficult task. 

Then, the weld depths penetration are controlled in a pulse-echo configuration because the weld bead (of width 2 mm) disturbs the detection when the pump and the probe beams are shifted of 2.2 mm. The results are presented in figure 8 (identical experimental parameters as in figure 7). The slow propagation velocities for gold-nickel alloy involve that the thermal component does not overlap the ultrasonic components, in particular for the echo due to the interaction with a lack of weld penetration. The acoustic response (V shape) is still well observed both for the slot of height 1.7 mm and for a weld depth penetration of 0.8 mm (lack of weld penetration of 1.7 mm), even with the weld bead. This is hopeful with regard to the difficulties encountered by conventional ultrasound in the case of the weld depths penetration. 

The CamuS system consists of a number of components, both hardware and software, as shown in Figure 1. The hub of the system is the data acquisition unit, which collects and stores ultrasonic data in the form of RF waveforms. An accurate probe position monitor provides information on the location and orientation of the probe as it is scanned over the test object. Software tools have been developed to provide assistance to the user with preparing inspection procedures according to the requirements of prEN1714 with visualising the data, in relation to the test object with making measurements of any indications present and with classifying indications. 

The coin-tap test is a widely used teclinique on thin filament winded beams for detection of disbonded and delaminated areas. However, since the sensitivity of this teclinique depends not only on the operator but also on the thickness of the inspected component, the coin-tap testing technique is most sensitive to defects positioned near the surface of the laminate. Therefore, it was decided to constructed a new scaimer for automated ultrasonic inspection of filament winded beams. A complete test rig illustrated in figure 6 was constructed in order to reduce the scanning time. While the beam rotates the probe is moved from one end to the other of the beam. When the scarming is complete it is saved on diskette and can then be evaluated on a PC. The scanner is controlled by the P-scan system, which enables the results to be presented in three dimensions (Top, Side and End view). 

Ultrasonic waves, produced by a sonicator, are transmitted into a suspension of cells by a metal probe (Figure E4.1C). The vibration set up by the ultrasonic waves disrupts the cell membrane, releasing the cell components into the surrounding aqueous solution. 

Both these geometric parameters altered diffusion data measured as Sherwood dimensionless number or as diffusion coefficients maxima and minima in these parameters mirrored nodes and antinodes from the ultrasound. This involved relative motions between the various components of several centimeters since the wavelength of sound at 20 kHz is of this order, depending on the medium. These workers were using electrochemistry as a probe to monitor ultrasonic power, and a fuller account of this work is given in another chapter of this volume, but the effects of geometry upon behavior of the electrochemical probe are noteworthy. 

The ReactlR MP unit is designed from a safety and performance perspective for operations in manufacturing environments. One of the operational problems occasionally encountered with in-line spectroscopic techniques is fouling of optical components. To avoid fouling of the probe and to insure a clean spectroscopic window, the ReactlR MP is equipped with a 200-W ultrasonic... 

ICP analyses were performed by Plasma Absorption Emission Spectroscopy (ICP-AES). BET surface areas were measured with a Micromeritics TriStar 3000 instrument after degassing the samples at 150 C under a 0.13 Pa vacuum overnight. XPS analyses were performed on a SSI X-probe spectrometer (SSX-100/206 photoelectron spectrometer Fisons) equipped with a monochromatized microfocused Al Ka X-ray source (1486.6 eV) and a hemispherical analyser. The binding energies were calculated relative to the C-(C, H) component of the adventitious Cls carbon peak fixed at 284.8 eV. Zeta potential measurements were carried out in a PENKEM Zeta Meter 500, using 25 mg of sample ultrasonically dispersed in 200 ml of an aqueous solution... 

The problem of ultrasonic Inspection through the austenitic cladding layer desposlted on the Inside of the pressure vessel of a PWR Is receiving much attention at the moment. The anisotropic nature of the austenite and the cusped Interface to the ferritic material causes severe distortion In the ultrasonic beam and hence degrades the subsequent sizing of defects within the ferritic component. A solution to this problem employed by some overseas utilities Is to use large diameter focused probes. 

Low-intensity ultrasonic waves are used for nondestructive probing to locate flaws in materials for which complete reliability is mandatory, such as those used in spacecraft components and nuclear reactor vessels. When an ultrasonic transducer emits a pulse of energy into the test object, flaws reflect the wave and are detected. Because objects subjected to stress emit ultrasonic waves, these signals may be used to interpret the condition of the material as it is increasingly stressed. Another application is ultrasonic emission testing, which records the ultrasound emitted by porous rock when natural gas is pumped into cavities formed by the rock to determine the maximum pressure these natural holding tanks can withstand. 

The second type of probe combines a microphone, to measure the pressxue, and an ultrasonic particle velocity transducer. Two parallel tdtrasonic beams are sent in opposite directions as shoAvn in Fig. A-10. The osdUatoiy motion of the air caused by audio-frequency sotmd waves produces a phase difference between the two ultrasonic waves at their respective detectors. This phase difference is related to the particle velocity component in the direction of the beams. This measme of particle velocity is multiplied directly by the pressme to give the soimd intensity. 

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