Checkline TI-25LT - Manual (Page 8)

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4 .0 G ET T I N G S TART ED
4.1 Connecting The Probe
Grasp the connector located at the end of the probe cable and carefully
insert the connector plugs into the receptacle located at the top edge of the
gauge. Make sure the connector is fully inserted into the receptacle. The
orientation of the plugs does not matter as they are non-polarized.
4.2 Turn On The Power
Press the ON/OFF key. All of the LCD Display elements will momentarily
illuminate. The firmware revision will then be momentarily shown
(for factory troubleshooting purposes only). Eventually the display will
show “0.000” (or “0.00” if using metric units), indicating it is ready for use.
Note: 1. The gauge is turned off by pressing the ON/OFF key again.
2. The gauge will automatically power off after 5 minutes of
non-use.
3. All settings will be retained in non-volatile memory.
4.3 “Zeroing” The Probe
The Probe Zero Plate is used to “zero” the probe for calibration purposes.
Normally, this procedure is required only when the probe is connected to
the instrument for the first time, but since this process takes less than 10
seconds, we recommend performing the Probe Zero function occasionally
as described below.
1. Check that the probe face (wear surface) is clean and free of debris.
2. Place a small drop of the supplied coupling fluid on the built-in
Probe Zero Plate located on the top of the gauge.
3. Press the probe firmly against the Plate.
4. The Stability Indicator on the LCD display should have six or
seven bars illuminated and a value should be shown in the display.
5. While maintaining probe contact with the Test Plate, press the
PROBE ZERO key. The display will show “Prb0” while the TI-25LT
calculates its zero point.
Note: The value shown on the display can be recorded and used in the
future to confirm that the gauge is functioning properly.
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4.4 Changing Units — inches to mm
To change the measuring units from inch (factory setting) to mm, press the
INCH/MM key. Each time the key is pressed, the units will change.
4.5 Checking Calibration With The Probe Zero Plate
Calibration can be checked using a sample of known thickness or using our
SB4H or SB4L 4-step calibration block.
4.6 Preparation Of The Surface
The surface to be measured should be relatively clean and smooth, free of
any small particulate, rust or scale. The presence of any of these conditions
will prevent stable and reliable readings. Often, a wire brush, sandpaper or
scraper will be helpful in cleaning the measurement surface. In situations
where the surface is heavily corroded or pitted, a rotary sander, or grinding
wheel will be necessary to properly prepare the surface for measurement.
If the surface is still “rough” after preparation, using a more viscous cou-
plant fluid similar to petroleum jelly or K-Y jelly will help obtain a stable,
reliable measurement. This type of “thick” coupling fluid is 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 the
coupling agent.
Extremely rough surfaces will prove most difficult to measure. These kinds
of surfaces act on the sound beam like frosted glass acts on light; the beam
becomes diffused and scattered in all directions.
Rough surfaces also contribute to excessive wear of the probe, The probe
should be inspected regularly for signs of uneven wear on the probe surface
(wearface). If this is detected, the probe should be returned to the factory
for repair or replacement.