Ultrasonic testing device
Ultrasonic testing devices are devices with which ultrasound is generated, introduced into a medium, received and evaluated.
All criteria do not always have to be met.
The first devices were built in Germany before 1950 by the companies Karl Deutsch Prüf- und Messgerätebau , Krautkrämer , Lehfeld and Siemens , and later by Sofranel, Ultrasonic / HBS, Branson, Rochar Eletronique and Panametrics.
Non-destructive material testing
An ultrasonic probe emits a sound pulse at a frequency suitable for testing between 500 kHz and 75 MHz. It then listens for the echo pulse that is reflected from the back wall or the flaw, similar to radar . The echo is shown as amplitude on a simple oscillographic ground glass .
Using the echo height and depth shown on the screen, flaws and cracks in the material can be located and thickness measurements can be carried out. In this type of application, the comparison error method is common, according to which the echo height in the test piece is compared with a reference body with the same material properties and known error size. It is also possible to calculate the depth of the flaw in the component after the adjustment to a known distance.
Standard are Digitalprüfgeräte, with an in pixels anzeigendem screen or display . These devices are not only more handy, but also show the echo height in percent (reflectivity of the discontinuities ) and their depth in millimeters when set correctly . Saving the snapshot of the screen (the so-called A-scan ) contributes to reproducible logging.
See also:
Leak detection
If a room to be tested (e.g. car body) is subjected to air pressure, the air escapes at leaks with an ultrasonic component in the noise spectrum.
This ultrasound component is located and measured with specially designed devices and the intensity is displayed digitally or graphically.
Distance and speed measurements
As airborne sound measuring arrangements, the devices designed for this purpose can be used to measure distances, signal movements, measure fill levels and record speeds. The main applications of such devices are in industrial process technology.
Examples from everyday life are distance measuring devices, parking aids, access detectors.
Medical diagnostics (sonography)
→ Main article: Sonography
The representation of the internal anatomy is possible through a computer-aided evaluation of the different transit times, densities and the associated absorptions or reflections. Mainly group emitters, so-called arrays, are used, which can be excited by the master computer to form certain sound beam shapes.
