10
TU_US-BA-e-1714
The upper figure is a bottom view of a typical transducer. The two semicircles are
visibly separated in the middle of the surface. One of the semicircles is conducting the
echoed sound back into the transducer. When the transducer is placed against the
material being measured, this is the area directly beneath the centre of the measured
surface.
The below figure is a top view of a typical transducer.
It is pressed against the top with the thumb or the index finger to hold the transducer
in place. Only moderate pressure is sufficient to keep it stationary. Its surface must be
placed flat against the surface of the material.
Table 3-1 Transducer selection
Model Freq
MHz
Diameter
mm
Measurement range
Lower limit Description
ATU-
US01
2
22
3.0mm
～
300.0mm(in steel
）
40mm(grey
Cast iron HT200)
20
For thick, highly at-
tenuating
or highly scattering
materials
ATU-
US09
5
10
1.2mm
～
230.0mm (in steel) Φ20mm×
3.0mm
normal
measurement
ATU-
US10
/90°
5
10
1.2mm
～
230.0mm(in steel
）
Φ20mm×
3.0mm
normal
measurement
ATU-
US02
7
6
0.75mm
～
80.0mm
(in steel
）
Φ15mm×
2.0mm
For thin pipe
wall or small
bent pipe wall
ATB-
US02
5
14
3
～
200mm
(in steel)
30
For high tempera-
ture (lower
than 300°C)
measurement
4.2 Conditions and preparation of surfaces
At any kind of ultrasonic measurement, the shape and roughness of the surface being
tested are of paramount importance. Rough and uneven surfaces may limit the pene-
tration of the ultrasound through the material resulted by an unstable and therefore
unreliable measurement.
