Checkline TI-CMXDL - Manual (Page 31)

3. Press the ENTER key to display the list of material types.
4. Press the UP and DOWN arrow keys to scroll through the
material list until the appropriate material is highlighted.
5. Press the ENTER key to overwrite the material type and
display the menu items with the new material type selected.
6. Finally, press the MEAS key to return to the measurement
screen and begin taking readings.
To calibrate the TI-CMXDL for a specific type of coating using
samples with known thicknesses, please refer to the chapter 9 –
Pulse-Echo Coating (PECT) or Coating (CT) for a complete expla-
nation of using the TI-CMXDL for coating measurements.
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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 back-
wall 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 subtracted 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 dur-
ing the inspection process.
The primary purpose of thru paint measurement is to determine actual or overall material
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 con-
junction 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-CMXDL, a basic echo-echo thru paint configuration is recalled
from memory. Each of the transducers in the list contains pre-configured echo-echo set-
tings. 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-CMXDL 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-CMXDL 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-CMXDL can also be configured for thru paint applications by selecting a factory
setup stored in the list of setups in the TI-CMXDL. Refer to section 12.0 for information
on recalling a setup. Once either the transducer type or setup has been selected, the
inspector is ready to begin making measurements.
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