SNDWAY SW-6510S, Руководство пользователя

Страница: 29 / 36

- 27 -
tested, the reading on the screen will change regularly, Select
the lowest value of the readings as the measured thickness of
the material. According to the curvature of the material, select
the correct direction of the angle between the probe crosstalk
barrier plate and the axis of the material to be tested. For pipes
with larger diameters, select the probe crosstalk barrier plate
perpendicular to the axis of the pipe; for pipes with smaller
diameters, select two measurement methods, parallel and
perpendicular to the axis of the pipe, and take the minimum
value of the readings as the measurement thickness.
B.1.5 Composite shape
When measuring materials with composite shapes (such as pipe
elbows), the method described above can be used, the difference
is that a second measurement is required, and the two values of
the probe crosstalk barrier plate perpendicular to the axis and
parallel to the axis are read respectively, the smaller of which
is taken as the thickness measurement of the material at the
measurement point.
B.1.6 Non-parallel surfaces
In order to obtain a stable and reliable thickness measurement
value, the other surface of the measured material must be
parallel or coaxial with the measured surface, otherwise it will
cause a large measurement error or no reading display at all.
B.2 Influence of temperature on measurement results
The thickness of the material and the propagation speed of
ultrasonic waves in the material are affected by temperature.
When the measurement accuracy is high, the test block com-
parison method can be used, that is, the test block of the same
material and approximate thickness is used for measurement
under the same temperature conditions, and the temperature
compensation coefficient is obtained, and this coefficient is
used to correct the measured value of the workpiece.