Development and manufacturing of non-
destructive testing units and system
Ultrasonic Flaw Detector NOVOTEST UD2301
31
9.2.
Measuring of prism delay for angle-beam transducer
During operation with the angle-beam transducer abrasion occurs
with prism, it cause to changes of angle and delay of the signal in
transducer. Given that the propagation of time in the prism
transducer significantly affect the accuracy of calculation of the
coordinates of the reflectors it is very important to accurately
measure the delay in the prism and periodically update this
parameter.
Measurement of prism delay of angle-beam transducer made using
a standard sample SO-3.
To measure delay in the prism it is necessary to get the reflected
signal from the radiused surface at the standard sample SO-3 and
put this signal into one of the control gates, for example gate A.
Configure the display of the measured parameters - display the
value of the propagation time along the beam for the required
control gate, in this example - La.
Time of propagation of ultrasonic vibrations in the prism of angle-
beam transducer in microseconds equals:
2t = t1
– 33,7 µs,
where t1 - the total time between the excitation pulse and the echo
signal from the concave cylindrical surface in the standard sample
SO-3 when the transducer is installed in a position corresponding to
the maximum amplitude of the echo signal, for this example - the
value La;
33,7 µs - the propagation time of the ultrasonic vibration in the
standard sample, calculated for the parameters: the radius of the
sample - 55 mm, the propagation velocity of the transverse wave in
the material sample -
3,26 mm/µs.
