((
#$*&#,$*4("('"
56
M
ODE: SET
Used to set the AWS measurement mode.
REF
Used to define the Indication Level (IL).
CURSOR
Used to move the cursor above the reference echo and set the reference
level.
MODE:
MEAS
Used to perform the measurements according to the standard.
IL Db
Indication Level: these are the dB’s needed to calibrate the indications to
the reference level.
AF dB
Attenuation Factor: is the attenuation in dB’s of the reference indication
based on the distance.
IR dB
Indication Rating: is the difference in dB’s between the indication and
reference gain with the attenuation factor correction.
Welding inspection using the AWS method
11. Calibrate the instrument for the welding test and set the trigonometric mode (See paragraph 4.4.1). In
this mode the data related to the ultrasound path, distance and depth of the indication are available for
the operator on the lower part of the screen;
12. Go to the AWS function of the main MEAS menu;
13. Select SET in the MODE video window using the
key;
1
4. Highlight the REF box and set the desired reference level; normally 80% of the screen height;
15. Put the coupling liquid on the surface;
16. Position the probe on the sample block and obtain the maximum signal height;
17. Select the CURSOR item and position it on the indication using the
and keys and confirm it by
p
ressing the SET key;
With the instrument calibrated in this manner it is possible to perform the indication measurements in
accordance with the AWS standards according to the procedure:
18. Select MEAS in the MODE video window using the
key;
1
9. Make sure Gate1 and the trigonometric measurement function are correctly set;
20. When the signal crosses the gate, the windows on the right display the values IL, AF, and IR according
to the following formula:
IR = IL – RG – AF
RG is the reference gain, i.e. the dB’s necessary to calibrate the sample flaw indication at the
reference level.
To Next Page
Loading...