YUSHI INSTRUMENTS
17
3.6 DAC Menu
Owing to the diffusion and attenuation of the sound velocity, the echo heights of the reflectors of
the same size depend on the distance between the reflector and the probe. The distance amplitude curve
is made according to different reference reflectors which are the same size but different in their depths,
and a curve diagram mode displays the influences and the changes. When the DAC curve is being made,
the material of the reference block with artificial flaws should be same as the work piece to be tested.
Note: When the DAC curve finished is activated, if you adjust some parameters, the prompt line
will display "a DAC curve has been made, the parameter is locked", if you really need to change the
parameter, you can close the DAC curve, and the DAC echo will be cleared. A new DAC curve will be
made after the adjustment.
Press
to enter the DAC menu.
3.6.1 DAC Echo
Select the DAC menu, press
(up) or
(down) to select the DAC echo submenu. Then
press
(left) or
(right) to adjust the value.
Note: The functional option of the DAC echo is used to display the current number of the echo
reference points, the maximum quality is 9, and confirm the echo reference points.
3.6.2 Gate A Start
Select the DAC menu, press
(up) or
(down) to select the Gate A start submenu. Then
press
(left) or
(right) to adjust the value.
Note: adjust the Gate A position to catch the reference echo. The adjustment range is 0-9999mm.
3.6.3 Distance Compensation(YUT-2820)
When penetrating through the work-piece, the sonic power of ultrasonic waves always attenuates
along with the enlargement of the spreading distance. When detecting the flaws of large work-pieces and
severe attenuated materials, the high receiving sensibility is required to discover the small flaw signals.
However, with the ultra high sensitivity, the crystal interface refection and probe disordered echoes will
be high and the near field blind area is enlarged. To solve this problem, YUT-28series is designed for
distance compensation. When the resolving power in the near field is not influenced, only the remote
signal will be compensated for its sensitivity so as to improve the testing range of the device
significantly. Before using this function, DAC curve should be made first.
Select the DAC menu, press
(up) or
(down) to select the TVG submenu. Then
press
(left) or
(right) to adjust. When shows OFF, close Distance Compensation, and ON
turn on the Distance Compensation.