Ultrasonic pulse-echo technique

Due to the outer circumference of the silo, about 25 meters, a non- or rarely destructive testing method was needed for the localization. Because the building was still in use, it was only accessable from the exterior side. We chose the ultrasonic pulse-echo-technique as an appropriate way of doing the testing. 

Hillger, W. Inspection of Concrete by Ultrasonic-Pulse-Echo-Technique, In Proceedings of the European Conference on Non Destructive Testing, Nice 1994, pp. II59-II63... 

Figure 10. Ultrasonic pulse-echo technique for determining the thickness of layers in multilayer materials.

Povey, M.J.W., Wilkinson, J.M. 1980. Application of ultrasonic pulse-echo techniques to albumen quality testing - a preliminary report. Br. Poult. Sci. 21, 489-495. 

The acoustic velocity of SiC has been measured using both ultrasonic resonance [1] and ultrasonic pulse echo techniques. The latter has resulted in the appearance of CVD-SiC diaphragms in commercially available speakers [2]. 

Figure 15.12 Ultrasonic pulse-echo technique for detection of adhesion flaws.

Tattersall, A.G., 1973, "The Ultrasonic Pulse-Echo Technique as Apphed to Adhesion Testing", J. Phys. D Appl. Phys, Vol. 6, pp819-832. 

Tattersall, H.G., 1973, The Ultrasonic Pulse-Echo Technique as Applied to Adhesion Testing, J. Appl. Phys.D., 6, 819-832. 

Ultrasonic Testing of Concrete with Fast Imaging Pulse-Echo-Technique. 

The common civil engineering seismic testing techniques work on the principles of ultrasonic through transmission (UPV), transient stress wave propagation and reflection (Impact Echo), Ultrasonic Pulse Echo (UPE) and Spectral Analysis of Surface Waves (SASW). 

PULSE-ECHO TECHNIQUES - Corrosion detecting processes which, by recording the action of ultrasonic waves artificially introduced into production structures, can determine metal thickness and detect flaws. 

The two major techniques in ultrasonic testing arc the pulse-echo mode and the through-transmission mode. In pulse-echo mode, the same transducer is used to emit and receive ultrasonic waves and requires access to only one side of the structure inspected (Fig. 12). The pulse-echo technique is effective on the near side skin laminate only, and the sensitivity decreases as a function of depth [29]. With the through-transmission mode, access to both sides of a structure is required as an emitter probe is placed on one side and a receiver on the other (Fig. 13). This technique measures the signal amplitude of ultrasonic waves transmitted through the material tested and is more sensitive to small defects than the pulse-echo mode. The detection of flaws throughout the whole depth of a... 

X = wave length of ultrasound, A = crystal size) perpendicular to the beam axis and a quarter of the pulse length along the beam axis. Taking typical values of A 10mm for conventional probes, A = 6mm for a SAFT probe, R = 100 mm and X 1 mm the lateral resolutions of the conventional pulse echo technique and SAFT are 10 mm and 1.5 mm respectively. Thus SAFT substantially Improves the lateral resolution of ultrasonics. SAFT therefore finds applications In... 

In recent years a number of other non-intrusive techniques for determining the contents and status of unopened munitions have been developed. These include neutron interrogation techniques such as neutron-induced prompt photon spectroscopy and hydrogen concentration measurement, and ultrasonic pulse echo and acoustic resonance techniques. Equipment based on the use of neutron-induced prompt photon spectroscopy has been fielded and successfully used by US EOD teams on many occasions over the last two years. This equipment, which is based on the analysis of photons emitted as the result of the interaction of neutrons with the chemical elements present in the munition and its contents, makes it possible to identify the presence or absence of key elements such as phosphorus, sulphur, chlorine, fluorine and arsenic within the munition. Clearly this information not only helps to identify the presence of a chemical fill, but in many circumstances also means that it is possible to identify the fill. 

Pulse echo technique-. A technique in which the reflection of an ultrasonic pulse on material heterogeneities is analyzed in order to characterize their in-depth position and extension. Time-of-flight technique A technique where the relation between the pulse paths at various positions of examined object or wave angles of incidence are used for the description of the acoustic impedance heterogeneities. 

Sidkey et al. [15] measured the longitudinal ultrasonic velocity and ultrasonic attenuation of four blend systems - namely Adiprene CM/NBR, Adiprene CM/ natural rubber (NR), Adiprene E/NR, and Adiprene E/NBR-at room temperature, using the pulse-echo technique. The relationship between the measured ultrasonic absorption and temperature and the glass transition temperature (Tg) of the... 

The pulse-echo technique is the most popular of the three basic ultrasonic, nondestructive testing techniques. The pulse-echo technique is very useful in detecting flaws and for thickness measurement. 

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