GE Krautkramer USM 35X, Руководство оператора

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Krautkramer USM 35X Issue 01, 04/2005 5-23
Operation
Calibrating the USM 35X
– Press to record the second calibration echo.
The correct calibration is confirmed by the message
“
Calibration is done ”. The material velocity and
probe delay are set. The value of the CAL function
goes back to 0.
– If necessary, check the calibration on one or several
known calibration lines, e.g. using the stepped
reference block VW.
H
Note:
Always keep in mind that the measured value is deter-
mined at the intersection point of gate and echo flank
when the function
TOF was set to flank . A correct set-
ting of the echo height and gate threshold is therefore
decisive for accurate calibration and measurement!
Calibrations or measurements in the peak mode are
mostly not possible when using dual-element (TR)
probes. As the echoes are often very broad and jagged,
a clear echo peak cannot always be found in these
cases.
5.8 Measuring
General notes
Please pay attention to the following notes when mea-
suring with the USM 35X.
• Condition for measurements is the correct instrument
calibration (sound velocity, probe delay).
• All amplitude measurements are carried out at the
highest or the first signal in the gate.
• All distance measurements are carried out at the
intersection point of gate and the first echo flank
(
TOF = flank or jflank ), or at the peak of the highest
echo ( TOF = peak ).
• If the echo amplitudes do not succeed 5 % screen
height all sound path and amplitude measurements
will be suppressed. Thus, rapidly changing random
measurements caused by the instrument’s back-
ground noise are avoided.
Krautkramer USM 35X Issue 01, 04/2005 5-23
Operation
Calibrating the USM 35X
– Press to record the second calibration echo.
The correct calibration is confirmed by the message
“
Calibration is done ”. The material velocity and
probe delay are set. The value of the CAL function
goes back to 0.
– If necessary, check the calibration on one or several
known calibration lines, e.g. using the stepped
reference block VW.
H
Note:
Always keep in mind that the measured value is deter-
mined at the intersection point of gate and echo flank
when the function
TOF was set to flank . A correct set-
ting of the echo height and gate threshold is therefore
decisive for accurate calibration and measurement!
Calibrations or measurements in the peak mode are
mostly not possible when using dual-element (TR)
probes. As the echoes are often very broad and jagged,
a clear echo peak cannot always be found in these
cases.
5.8 Measuring
General notes
Please pay attention to the following notes when mea-
suring with the USM 35X.
• Condition for measurements is the correct instrument
calibration (sound velocity, probe delay).
• All amplitude measurements are carried out at the
highest or the first signal in the gate.
• All distance measurements are carried out at the
intersection point of gate and the first echo flank
(
TOF = flank or jflank ), or at the peak of the highest
echo ( TOF = peak ).
• If the echo amplitudes do not succeed 5 % screen
height all sound path and amplitude measurements
will be suppressed. Thus, rapidly changing random
measurements caused by the instrument’s back-
ground noise are avoided.