Dakota PR-82 User Manual

OPERATION MA

NUAL

P/N P

-

102

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0004

Rev 1.

9

0,

January

200

8

DAKOTA ULTRASONICS MODEL PR-82 SONIC TESTER

Copyright  2008 Dakota Ultrasonics. All rights reserved.

No part of this publication may be reproduced, translated into another
language, stored in a retrieval system, or transmitted in any form or by any
means; electronic, mechanical, photocopying, recording, or otherwise,
without the prior written consent of Dakota Ultrasonics.

Every precaution has been taken in the preparation of this publication.
Dakota Ultrasonics assumes no responsibility for errors or omissions.
Neither is any liability assumed for damages resulting from the use of
information contained herein.

Any brand or product names mentioned herein are used for identification
purposes only, and are trademarks or registered trademarks of their
respective holders.

1500 Green Hills Road. #107, Scotts Valley, CA 95066 USA

Tel [phone] Fax [phone]

http://www.dakotaultrasonics.com

CONTENTS

PR-8 2 Ultrasonic Thickness Gauge

INTRODUCTION
OPERATION

THE KEYPAD
THE DISPLAY
THE TRANSDUCER
MAKING MEASUREMENTS
CONDITION AND PREPARATION OF SURFACES
PROBE ZERO
CALIBRATION

SCAN MODE
TRANSDUCER SELECTION
APPENDIX A: PRODUCT SPECIFICATIONS
APPENDIX B: APPLICATION NOTES

1
3
3
6
8

9
11
12
13
17
18
21
23

APPENDIX C: SOUND VELOCITIES OF COMMON MATERIALS
WARRANTY INFORMATION

27
29

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 Dakota Ultrasonics model PR-82 is a precision Ultrasonic
Micrometer. Based on the same operating principles as SONAR, the PR-82
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 PR-82, 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 notes and a table of
sound velocity values for various materials.

Dakota Ultrasonics 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:

• Dakota Ultrasonics, Green Hills Road #10 7
Scotts Valley, California 95066 USA

• Telephone: [phone]

• Facsimile: [phone]

• www.dakotaultrasonics.com

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OPERATION

The PR-82 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

This key is used to turn the PR-82 on and off. When the tool is turned
ON, it will first perform a brief display test by illuminating all of the

segments in the display. After one second, the tool 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 tool is ready
for use.

The PR-82 is turned OFF by pressing the ON/OFF key. The tool has a
special memory that retains all of its settings even when the power is off.
The tool also features an auto-powerdown mode designed to conserve
battery life. If the tool is idle for 5 minutes, it will turn itself off.

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The PRB- 0 key is used to "zero" the PR-82 in much the same way that
a mechanica l micrometer is zeroed. If the tool is not zeroed correctly, all of

the measurements that the tool makes may be in error by some fixed value.
Refer to page 12 for an explanation of this important procedure.

The CAL key is used to enter and exit the PR-82's calibration mode.
This mode is used to adjust the sound-velocity value that the PR-82 will use

when calculating thickness. The tool will either calculate the sound-velocity
from a sample of the material being mea sured, or allow a known velocity
value to be entered directly. Refer to page 13 for an explanation of the two
CAL functions available.

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 tool is

displaying a thickness (IN or MM) or a velocity value (IN/µs or M/s).

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The UP arrow key has two functions. When the PR-82 is in calibration
mode, this key is used to increase numeric values on the display. An auto­repeat function is built in, so that when the key is held down, numeric

values will increment at an increasing rate. When the PR-82 is not in
calibration mode, the UP arrow key switches the SCAN measurement
mode on and off. Refer to page 17 for an explanation of the SCAN
measurement mode.

The DOWN arrow key has two functions. When the PR-82 is in the CAL
mode, this key is used to decrease numeric values on the display. An
auto-repeat function is bu ilt in, so that when the key is held down, numeric
values will decrement at an increasing rate. When the PR- 82 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 PR-82 is
actually making a measurement.

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The Display

The numeric portion of the display consists of 4 complete 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 PR-82 is displaying thickness measurements, the display will hold
the last value measured, until a new measurement is made. Additionally,

when the battery voltage is low, the entire display will begin to flash.
When this occurs, the batteries should be replaced.

These eight vertical bars form the Stability Indicator. When the PR-82 is
idle, only the left -most bar and the underline will be on. When the tool is
making a measurement, six or seven of the bars should be on. If fewer

than five bars are on, the PR-82 is having difficulty achieving a stable
measurement, and the thickness value displayed will most likely be
erroneous.

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When the IN symbol is on, the PR-82 is displaying a thickness value in
inches. The maximum thickness that can be displayed is 19.999 inches.

When the MM symbol is on, the PR- 82 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 symbol is on, in conjunction with the /µs symbol, the PR-82
is displaying a sound-velocity value in inches- per-microsecond.

When the M symbol is on, in conjunction with the /s symbol, the PR- 82
is displaying a sound-velocity value in meters-per-second.