NDT Experts ExScan1000 User manual

ULTRASONIC
THICKNESS GAUGE
ExScan1000
www.okondt.com

CONTENTS
Introduction........................................................4
Operation...........................................................6
The Keypad.......................................................6
The Display........................................................12
The Transducer .................................................18
Making Measurements ......................................21
Condition and Preparation of Surfaces..............24
Probe Zero.........................................................26
Calibration .........................................................29
Scan Mode ........................................................35
APPENDIX A Product Specifications.................37
APPENDIX B Application Notes ........................39
APPENDIX C Sound Velocities of some
Common Materials.............................................42

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DISCLAIMER
Inherent in ultrasonic thickness measurement
is the possibility that the instrument will use the
second rather than the first echo from the back
surface of the material being measured. This may
result in a thickness reading that is TWICE what it
should be. Responsibility for proper use of the
instrument and recognition of this phenomenon
rests solely with the user of the instrument.

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INTRODUCTION
The NDT Experts model ExScan1000 is a
precision Ultrasonic Micrometer. Based on the
same operating principles as SONAR, the
ExScan1000 is capable of measuring the thickness
of various materials with accuracy as high as
± 0.001 inches, or ± 0.01 millimeters. The principle
advantage of ultrasonic measurement over
traditional methods is that ultrasonic
measurements can be performed with access to
only one side of the material being measured.
This manual is presented in three sections.
The first section covers operation of the
ExScan1000, and explains the keypad controls
and display. The second section provides
guidelines in selecting a transducer for a specific
application. The last section provides application

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notes and a table of sound velocity values for
various materials.
NDT Experts maintains a customer support
resource in order to assist users with questions or
difficulties not covered in this manual. Customer
support may be reached at any of the following:
2718 Westside Drive
Pasadena, TX 77502
USA

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OPERATION
The ExScan1000 interacts with the operator
through the membrane keypad and the LCD
display. The functions of the various keys on the
keypad are detailed below, followed by an
explanation of the display and its various symbols.
The Keypad

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This key is used to turn the ExScan1000 on
and off. When the gauge is turned ON, it will first
perform a brief display test by illuminating all of the
segments in the display. After one second, the
gauge will display the internal software version
number. After displaying the version number, the
display will show "0.000" (or "0.00" if using metric
units), indicating the gauge is ready for use.
The ExScan1000 is turned OFF by pressing
the ON/OFF key. The gauge has a special memory
that retains all of its settings even when the power
is off. The gauge also features an auto-power
down mode designed to conserve battery life. If the
gauge is idle for 5 minutes, it will turn itself off.

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The PRB-0 key is used to "zero" the
ExScan1000 in much the same way that a
mechanical micrometer is zeroed. If the gauge is
not zeroed correctly, all of the measurements that
the gauge makes may be in error by some fixed
value. Refer to page 27 for an explanation of this
important procedure.
The IN/MM key is used to switch back and
forth between English and metric units. This key
may be used at any time, whether the gauge is
displaying a thickness (in or mm) or a velocity
value (IN/µs or m/s).

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The CAL key is used to enter and exit the
ExScan1000's calibration mode.
This mode is used to adjust the sound-velocity
value that the ExScan1000 will use when
calculating thickness. The gauge will either
calculate the sound-velocity from a sample of the
material being measured, or allow a known velocity
value to be entered directly. Refer to page 29 for
an explanation of the two CAL functions available.

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The UP arrow key has two functions. When
the ExScan1000 is in calibration mode, this key is
used to increase numeric values on the display. An
auto-repeat function is built in, so that when the
key is held down, numeric values will increment at
an increasing rate. When the ExScan1000 is not in
calibration mode, the UP arrow key switches the
SCAN measurement mode on and off. Refer to
page 35 for an explanation of the SCAN
measurement mode.

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The DOWN arrow key has two functions.
When the ExScan1000 is in the CAL mode, this
key is used to decrease numeric values on the
display. An auto-repeat function is built in, so that
when the key is held down, numeric values will
decrement at an increasing rate. When the
ExScan1000 is not in calibration mode, the DOWN
arrow key switches the display backlight between
three available settings. OFF will be displayed
when the backlight is switched off. AUTO will be
displayed when the backlight is set to automatic
mode, and ON will be displayed when the backlight
is set to stay on. In the AUTO setting, the backlight
will illuminate when the ExScan1000 is actually
making a measurement.

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The Display
The numeric portion of the
display consists of 4 com-
plete digits preceded by a
leading "1", and is used to
display numeric values, as well as occasional
simple words, to indicate the status of various
settings.
When the ExScan1000 is displaying
thickness measurements, the display will hold the
last value measured, until a new measurement is
made.

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These sixteen vertical bars
form the Stability Indicator.
When the ExScan1000 is
idle, only the left-most bar
and the underline will be on.
When the gauge is making a measurement,
ten or twelve of the bars should be on. If fewer
than five bars are on, the ExScan1000 is having
difficulty achieving a stable measurement, and
the thickness value displayed will most likely be
erroneous.
When the IN symbol is on,
the ExScan1000 is
displaying a thickness value
in inches. The maximum
thickness that can be
displayed is 19.999 inches

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When the MM symbol is
on, the ExScan1000 is
displaying a thickness
value in millimeters.
If the displayed thickness exceeds
199.99 millimeters, the decimal point will shift
automatically to the right, allowing values up to
1999.9 millimeters to be displayed.
When the in/us symbol is
on, the ExScan1000 is
displaying a sound-velocity
value in inches-per-
microsecond.
When the m/s symbol is on,
the ExScan1000 is
displaying a sound-velocity
value in meters-per-
second.

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When performing the manual
thickness measurement, the M
symbol is illuminated on the
display.
When switching on the
scanning mode, the S symbol
is illuminated on the display.
The H1symbol is appeared
after pressing button –
calibrating the sound velocity
at a known thickness (1 point
calibration).
When the H2 symbol is on,the
ExScan1000 is performing the
2 point calibration.

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When the Z symbol is on, the
ExScan1000 is performing
the probe zero calibration.
When the V symbol is on, the
ExScan1000 is performing
the calibration by the known
sound velocity in a test block.
When the Prb0 symbol is on,
the ExScan1000 is finishing
the probe zero calibration.
The symbol for switching on
the mode of auto display illumination.
When the On symbol is on,
the ExScan1000 is switching
on the mode of constant
display illumination.

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When the OFF symbol is on,
the ExScan1000 is switching
off the display illumination.
When the Auto symbol is on,
the ExScan1000 is switching
on the auto mode display
illumination with direct
measurements.
When the 1-OK symbol is on,
the ExScan1000 is
performing the 2 point
calibration, the calibration of
the 1st point.
When the 2-OK symbol is on,
the ExScan1000 is perfor-
ming the 2 point calibration,
the calibration of the 2nd point

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This symbol indicates the
battery charge status. When
the battery needs to be
charged this symbol start
flashing.
The Transducer
The transducer is the "business end" of the
ExScan1000. It transmits and receives the
ultrasonic sound waves which the ExScan1000
uses to calculate the thickness of the material
being measured. The transducer connects to the
ExScan1000 via the attached cable, and two
coaxial connectors. When using transducers
manufactured by NDT Experts, the orientation of

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the dual coaxial connectors is not critical: either
plug may be fitted to either socket in the
ExScan1000.
The transducer must be used correctly in
order for the ExScan1000 to produce accurate,
reliable measurements. Below is a short
description of the transducer, followed by
instructions for its use.
This is a bottom view of a typical transducer.
The two semicircles of the wearface are visible, as
is the barrier separating them. One of the
semicircles is responsible for conducting ultrasonic
sound into the material being measured, and the
other semicircle is responsible for conducting the
echoed sound back into the transducer. When the

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transducer is placed against the material being
measured, it is the area directly beneath the center
of the wearface that is being measured.
This is a top view of a typical transducer.
Press against the top with the thumb or index
finger to hold the transducer in place. Moderate
pressure is sufficient, as it is only necessary to
keep the transducer stationary, and the wearface
seated flat against the surface of the material being
measured.