Design And Functioning - NOVOTEST UD3701 Operation Manual

Figure 1.5 - Appearance of the angle beam single element probe
P122 – Angle beam dual element probe
These probes mostly are used for NDT of girth welds of pipe elements from steel and
polyethylene with 14-219 mm diameter and 2-6 mm thickness.
Probes are applied for testing of thin welds, mostly from stainless and mild steels, aluminum
alloys. Characteristic feature of the probe – minimal dead zone and UT waves focus in the particular
thickness range.
Figure 1.6 – Appearance of the angle beam dual element probe

1.6 Design and functioning

Operating principle of flaw detector is based on the ultrasonic contact NDT method, which uses
the properties of UT waves to reflect from the borders between materials with different acoustic
impedance.
UT waves are generated due to UT probe ability to transfer electric impulse into mechanical
waves (UT waves). UT probe emits ultrasonic impulse into the tested object. Echo signal is reflected
from the defect or the product back side and received by the ultrasonic transducer. Then received
electrical signals are magnifying, converting to digital, are processing and outputting to the display.
Received echo signals are performing on the device display as A-scan.
Operator analyzes A-scan and decides about presence of the defect in product, its location and
equal dimensions. For determination of defect depth, the following formula is applied:
where Н – distance between entry point of UT waves and defect, m;
С – velocity of UT waves in tested object, m/s;
t – time of UT waves to pass from entry point to the defect and turn back, s.
Ultrasonic Flaw Detector NOVOTEST UD3701
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Operation manual
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