Checkline TI-MVX - Manual (Page 27)

to measuring. Users will often use pulse-echo mode and echo-echo mode in
conjunction when performing inspections on coated materials.
Thru coating measurements require special high damped transducers. The most
common transducers are the 3.5, 5, and 7.5MHz hi damped transducers. These
transducers are suitable for use in both pulse-echo and echo-echo modes. This
conveniently enables the user to accurately measure overall material thickness
using the thru Coating mode, and then conveniently switch to pit detection mode
without changing transducers.
Thin materials
Use pulse echo mode and a high frequency transducer for these types of appli-
cations. The most common transducers are the 7.5MHz and 10MHz models with
extra resolution. The higher frequencies provide greater resolution and a lower
minimum thickness rating overall.
High temperature
Use and select a special 2.25MHz and 5 MHz High temperature transducer for
these types of applications. Both pulse-echo and echo-echo modes will also
work for these applications. However, echo-echo mode will eliminate error
caused by temperature variations in the delay line of the transducer.
Noisy Material
Materials such as titanium, stainless steel, and aluminum may have inherent sur-
face noise issues. This is a signal that appears at the surface of the material
when using a dual element delay line probe. Select a higher frequency transduc-
er to reduce this noise – 7.5MHz and higher for better resolution. Alternatively,
enable a single gate to block this noise. See the section Gate 1 on page 50 for
more information.
Restricted access
In order to measure materials with lots of curvature or restricted access, use and
select higher frequencies with smaller diameters. The smallest diameter uses
3/16” crystals with a contact area of .250”.
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Alternatively, Gate 2 can be selected from the menus and adjusted as follows:
1) Press the MENU key once to activate the menu
items tab. Press the MENU key multiple times to
tab right and the ESC key multiple times to tab left
until the GATE menu is highlighted and displaying
the submenu items.
2) Use the UP and DOWN arrow keys to scroll
through the sub menu items until GATE 2 is high-
lighted.
3) Press the LEFT and RIGHT arrow keys to scroll
the value. When the correct gate value is being
displayed, proceed to step 8.
4) Alternatively, press the ENTER key to display
the Digits Edit Box.
5) Press the UP and DOWN arrow keys to scroll the highlighted value.
6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.
7) Repeat steps 5 & 6 until the GATE 2 value is correctly displayed.
8) Press the OK key to set the gate and return to the menu screen, or ESC to
cancel entering the gate value.
9) Finally, press the MEAS key to return to the measurement screen and begin
taking readings.
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