Checkline TI-45N - Manual (Page 8)

TI-45N Operating Instruction Guide
8
5.0 Q UICK S TART I NSTRUCTIONS - S TEEL T HICKNESS
These Quick Start procedures are intended for those applications where the thickness of
steel is to be measured.
If a material other than steel will be measured, the acoustic velocity must be adjusted
to the appropriate value. In this case refer to Changing Acoustic Velocity Settings in sec-
tion 6.3
1. Turn the power on by pressing the POW key.
2. Check the calibration by placing a drop of coupling on the built-in calibration
disc on the front face of the gauge.
3. Grasp the probe and place it on the calibration disc.
4. The display should show a reading of 0.197 Inch ±0.001" or 5.00 mm ±0.01 mm,
along with the Good Coupling Indicator located in the upper left side of the
LCD display. The indicator will remain on the display while the probe is in
contact with the sample.
5. If the gauge shows any other value press the ZERO key while the probe remains in
contact with the calibration disc. The reading should then be adjusted to read
correctly. The gauge is now ready to perform thickness readings on steel samples.
6. Place a small amount of coupling fluid on the steel surface to be measured and
proceed as indicated in step 3 above.
7. The gauge will display the thickness of the steel wall along with the Good
Coupling Indicator. The Indicator will remain on the display while the probe is
in contact with the sample. If the Indicator is not displayed, then the measurement
was not successful and should be repeated.
Good Coupling
Indicator
TI-45N Operating Instruction Guide
17
7.1 Notes On Measurements
1. The following surface conditions can prevent accurate measurements.
(Refer to section 7.2 Preparing The Surface For Measurement.)
• More than 0.012" (12 mils or 300 microns) of paint or other coating
• Flaking or loosely adhered coatings
• Rough or heavily-pitted surface
2. If the Good Coupling Indicator is not shown on the display when the
probe is in contact with the sample or if it flashes on and off, the
following possibilities could exist:
• Some foreign substance (other than coupling fluid) could be present
between the probe and the sample (i.e. dust, sand, dirt, etc.)
• Extent of corrosion is too heavy
• A problem exists in the receiving (green) side of the cable or connector
3. If two materials are press-fitted or laminated together, the gauge will only
read the thickness of the sample that the probe contacts.
4. Pipes with outer diameters less than 1 Inch (25 mm) cannot be measured.
Specify Model TI-25.
5. Measurement of materials at or above 140 °F (60 °C) will damage the probe
and should be avoided.
7.2 Preparing The Surface For Measurement
The TI-45N Gauge can be used to measure thickness over existing paint or
coatings as long as the coating is in good condition, is well adhered to the
surface and does not exceed 0.012" (12 mils or 300 microns) in thickness.
Please note that the paint or coating thickness will be included in the overall
wall thickness measurement.
If the surface to be measured is rusty, heavily pitted or corroded, it will have
to be prepared using a wire brush, grinder, file or sandpaper. Additionally, if
the surface is still rough after preparation, use of a more viscous couplant
fluid (i.e. water-based K-Y Jelly) will help obtain a good acoustic coupling.
K-Y Jelly is also a good choice when measuring on vertical surfaces or on
the underside as it will help adhere the probe to the measurement surface
while also acting as a coupling agent.