20
Quick selection to
"
TEST
"
,
"
SETTINGS
"
,
"
VIEW
"
,
"
ARCHIVE
"
,
"
CALIBRATION
"
inserts is carried out by pressing
,
,
,
,
keys.
"
Hot keys
"
which are operated by
"
F1
"
,
"
F2
"
,
"
F3
"
function keys are
situated on the keypad of the flaw detector:
−
F1 (Balancing)
1
– to balance the signal, place it in the screen center
and clear the flaw detector screen;
−
F2 (Full-screen mode) – the complex plane and time chart is
maximized to fill the entire screen.
−
F3 (Centering) – to place the signal in the screen center and clear the
flaw detector screen;
“Balancing”
– it is hardware compensation of input signal. It is carried
out by summation of input signal with reference signal of the same amplitude
but opposite in phase. Current procedure is conducted after preamplifier
according to radio signal (before signal detecting). Balancing algorithm is
iterative and takes some time. The procedure is necessary for ECP non-
balance voltage compensation. After the balancing of flaw detector the
centering is carried out automatically.
“Centering”
– it is a displacement of present (complex) signal in user
selected position on the screen of the flaw detector. The algorithm is fully
performed by processor module. Current procedure is carried out according
to digital detecting signal and necessary for signal displacement elimination
caused by amplifier and digital filters.
Balancing should be applied in case if:
−
ECP type was changed;
−
One of following parameters was changed: ECP frequency, gain
coefficient, preamplification coefficient, ECP excitation voltage;
−
Testing object was changed.
Centering should be used if the operator needs to set the signal in the
complex plane centre.
1
"
F, Hz"- operating frequency of probe
2
; varied in the range from 10
Hz to 16 МHz with a step of 1, 10, 100, 1000, 10000, 100000, 1000000,
10000000 Hz.
1
Balancing of the flaw detector is required after the ECP operating frequency was set or changed.
Also, the balancing should be carried out after the ECP replacement. If the flaw detector was once
balanced and its operating frequencies were not changed, it is possible to carry out centering.