Determination Of Reference Values Of Conventional Response, Range Of The Control Gate And Signal/Noise Ratio - NOVOTEST UD3701 Operation Manual

 level of excitation generator – U1 («Energy – U1»);
 level of the gate – 50 % (parameter group «Gates» parameter «Level – 50%»);
 method of echo-signal measurement – by peak («MEAS – PEAK»);
 averaging of signals – 4 (parameter group «Func» parameter «AVG – 4»);
 probe type – dual element («DUAL - ON»).
4. Get on the screen the signal from generator. Overlay A-gate on it.
5. Set alarm activation DTC for A-gate when the signal is higher the gate level (mode
«MORE»).
6. Set minimum time for the gate, but under the condition that the whole signal is within the
gate.
7. Set A-gate level 80 % of the screen.
8. Correct the signal level on the screen to 80 % of flaw detector screen by control keys of
generator AFG320 amplitudes AFG320 (by visual monitoring and alarm activation DTC).
9. Determine the signal amplitude on the screen by changing the «Attenuation» controls of
tester attenuator according to Table 3.3. Amplitude height should not exceed permissible
values from Table 3.3.
10. Repeat p. 2 – 10 for frequency values: 1,2; 1,8; 5,0; 10 MHz.
11. For every frequency value, signal amplitude on the screen should comply with values
shown in Table 3.3.
Table 3.3 – Receiver level for linearity of vertical scanning
Setting of external
attenuator, dB
3.2.7 Determination of reference values of conventional response, range of the control gate
and signal/noise ratio
1. Connect single-element angle beam probe P121-5-50-М-003 to generator output.
2. Set the following flaw detector parameters:
 measurement range 100 mm («RANGE – 100 mm»);
 receiver frequency 5 MHz («FREQ – 5 MHZ»);
 probe angle – 50° («ANGLE – 50»);
 level of excitation generator – U3 («Energy – U3»);
 gate level – 50 % (parameter group «Gates» parameter «Level – 50%»);
 method of echo-signal measurement – by peak («MEAS – PEAK»);
 probe type – single element («DUAL – OFF»).
3. Put the probe, through couplant, on the standard calibration block SО-1 and receive echo-
signal from the nearest reflector with 2 mm diameter and 5 mm depth. Drive echo-signal to
normal level (50 % of screen height) by gain control keys. Record value of conventional
response in dB (N
Reference amplitude,
% of the screen
0
1
3
5
7
11
13
19
25
).
s
Ultrasonic Flaw Detector NOVOTEST UD3701
Measured amplitude,
% of the screen
90 88 - 92
80 Starting level
64 62 - 66
50 48 - 52
40 38 - 42
25 23 - 27
20 18 - 22
10 8 - 12
5
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