Checkline TI-CMX - Manual (Page 21)

Coating Only
The coating only mode should be used when the application calls for coating measure-
ments only and the user is not interested in the thickness of the material the coating has
been applied to. This mode can also be used as a stand alone coating thickness gauge,
where the coating has not been applied to another material surface. An auto identified
coating probe must be attached to the TI-CMX in order to enable this mode.
Thin materials
Use pulse echo mode and a high frequency transducer for these types of applications.
The most common transducers are the 7.5MHz and 10MHz models with extra resolu-
tion. 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 surface
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 transducer to reduce this noise
– 7.5MHz and higher for better resolution.
Restricted access
Measuring materials with extreme curvatures or restricted access, higher frequencies
with smaller diameters should be considered. The smallest diameter uses 3/16” crystals
with a contact area of .250”. Custom transducers are available on request.
5.3 Factory Setup Chart
There are no standard factory setups provided with the TI-CMX, as the primary reason
for the setups is to retain all of the user adjustments made to set the gauge for use on a
specific application. Saving a setup allows you to retain all of the settings made to tune
the gauge, such as Gain setting, 1 or 2 Point Calibration values for the Material and/or
the Coating, Acoustic Velocity setting, Alarm limits, operating mode, B-scan settings
and much, much more. Refer to section 11.0 for additional info on Setups.
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8.0 T HRU -P AINT M EASUREMENT T ECHNIQUE
8.1 Introduction to Thru Paint Measurement
The principle behind thru paint measurement is by measuring the time between two
backwall echoes returning from the test material. Since both of these backwall echoes
travel the same path through the paint or coating, the thickness of the coating is subtract-
ed out of the measurement so that only the actual material thickness can be measured.
This feature saves the user a great deal of time scraping and removing the coating from
tanks and pipes during the inspection process.
The primary purpose of thru paint measurement is to determine actual or overall materi-
al thickness by eliminating the coating thickness. Thru paint mode cannot be used for
flaw or pit detection. Therefore, inspectors may need to use echo-echo thru paint mode
in conjunction with the standard pulse-echo flaw detection mode for some applications.
Chassis tubing inspectors and sanctioning bodies will use the echo-echo mode for tubing
with powder coatings, and pulse-echo mode for tubing without coating. The combination
of using both modes is ideal for the advanced inspectors needs.
8.2 Using Thru Paint Mode
The first thing to note in this section, is that by selecting the transducer type from the
list of probes stored in the TI-CMX, a basic echo-echo thru paint configuration is
recalled from memory. Each of the transducers in the list contains pre-configured echo-
echo settings. The standard transducer that will be used for common steel applications
_” 5MHz high damped transducer (1/4IN – 5.0MHZ HD). This is the recommended
transducer for this industry and should be used for thru paint applications. Any of the
auto recognition coating transducers are also high damped transducers and will work in
echo-echo mode as well.
NOTE: When a transducer is selected for use, all of the measurement modes available
for use with this transducer can easily be determined by pressing the multi-mode button
on the keypad. The TI-CMX has been programmed to identify the modes available to a
specific transducer.
Once the transducer type has been selected and the appropriate calibration procedure
completed, the TI-CMX can toggle between pulse-echo (flaws & pits), and echo-echo
(thru paint) modes by simply pressing the MULTI MODE key located on the keypad.
Refer to section 6.0 for additional information.
The TI-CMX can also be configured for thru paint applications by selecting a factory
setup stored in the list of setups in the TI-CMX. Refer to section 11.0 for information on
recalling a setup. Once either the transducer type or setup has been selected, the inspec-
tor is ready to begin making measurements.
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