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5.7.1 To Adjust the Gain Value
The quickest way to adjust GAIN is directly from the hot menu. Alternatively, adjust the value using
the menus:
1.
Select MENU/TUNE/GAIN and adjust using LEFT and RIGHT or press ENTER to use the
DIGITS EDIT BOX
2.
Press OK to set the value
3.
Press MEAS to return to the measurement screen.
5.8 THRESHOLD
The threshold is the level of signal amplitude required to trigger a gate and activate the digital
thickness reading. Increasing the threshold value decreases the sensitivity of the gauge as a more
powerful signal is required to trigger the gate. For example on the A-scan display it may be clear
that there is a flaw in the material but the thickness reading is not taking this into account; lowering
the threshold has the effect of increasing the sensitivity of the gauge to a level that the flaw can be
detected. More information on thresholds can be found on the Elcometer NDT Knowledge Centre
on www.elcometerndt.com
5.8.1 To Adjust the Threshold Value
The threshold value may be adjusted from the hot menu when in the P-E GT or E-E measurement
mode.
5.9 GATES
Your gauge is equipped with gates which control the time measurement process. Further
information on gates can be found on the Elcometer NDT Knowledge Centre on
www.elcometerndt.com.
5.10 .FRONT PANEL LIGHTS
The green light illuminates when t
he alarm mode is active and the measured thickness is within
limits.
The red light illuminates when t
he alarm mode is active and the measured thickness is less than
the alarm low value, or the measured thickness is greater than the alarm high value.
6 MEASUREMENT - MODES
To select the measurement mode, press MULTI MODE and select the transducer type and
measurement mode from the list, see “Setting Up the Gauge” on page 12 for details.
The availability of the modes depends upon the type of transducer fitted to the gauge.
6.1 PULSE-ECHO MODE (P-E)
This mode measures from the initial pulse (sometimes referred to as an artificial zero) to the first
echo (reflection). This mode only requires one reflection and it is therefore the most sensitive mode
for measuring weak reflections (flaws) typically found when measuring heavily corroded metals. If
this mode is used to measure a coated sample, then the thickness of the substrate plus coating will
be measured.
6.2 PULSE-ECHO MODE (P-E GT)
This is the same as the standard Pulse-Echo mode described above, but Gate 1 is active.
6.3 ECHO-ECHO MODE (E-E)
This mode measures between two reflections. This technique is commonly used to eliminate errors
from surface coatings and also to make measurements in multiple layered materials. The
disadvantage is that two echoes are needed which requires a much stronger echo (reflection).
