DAKOTA ULTRASONICS MiniMax v2.0 User manual

OPERATION MANUAL
DAKOTA ULTRASONICS
MiniMax v2.0
Ultrasonic Bolt Tension Monitor
P/N P-156-0005 Rev 3.00, June 2019

Table of Contents
CHAPTER ONE INTRODUCTION ..................................................................... 1
1.1 GENERAL DISCLAIMER .......................................................................................................... 1
1.2 SAFETY ................................................................................................................................ 1
1.3 WARRANTY .......................................................................................................................... 2
CHAPTER TWO ABOUT THIS MANUAL ......................................................... 3
2.1 NEW TO ULTRASONICS? ....................................................................................................... 3
2.2 NEW TO FASTENER MEASUREMENT? ..................................................................................... 3
2.3 MINIMAX OVERVIEW ............................................................................................................. 3
2.4 TABBED & HOT MENU REFERENCE ....................................................................................... 6
CHAPTER THREE QUICK START GUIDE ....................................................... 8
3.1 OVERVIEW ........................................................................................................................... 8
3.2 GETTING THE MINIMAX READY .............................................................................................. 8
3.3 SETTING UP THE MINIMAX .................................................................................................... 8
3.4 CREATING A NEW GROUP TO STORE MEASUREMENTS ........................................................ 11
3.5 SETTING THE APPROXIMATE LENGTH .................................................................................. 19
3.6 MEASURING REFERENCE LENGTHS ..................................................................................... 22
3.7 MEASURING ELONGATIONS ................................................................................................. 23
CHAPTER FOUR KEYBOARD, MENU, & CONNECTOR REFERENCE ....... 25
4.1 MENU KEY (OPERATION & SUB MENUS) .............................................................................. 25
4.2 CAL – MENU ...................................................................................................................... 27
4.3 MATL (MATERIAL) – MENU ................................................................................................. 28
4.4 GEOM (GEOMETRY) – MENU ............................................................................................. 28
4.5 DISP (DISPLAY) – MENU .................................................................................................... 29
4.6 TUNE – MENU .................................................................................................................. 30
4.7 GATES – MENU ................................................................................................................ 31
4.8 AUTO – MENU .................................................................................................................. 31
4.9 SETUP – MENU ................................................................................................................ 32
4.10 DATA – MENU ................................................................................................................ 32
4.11 UTIL (UTILITIES) – MENU ................................................................................................. 33
4.12 XFER (TRANSFER) – MENU ............................................................................................. 34
4.13 CLR (CLEAR) KEY ............................................................................................................ 34
4.14 MEAS (MEASUREMENT MODE) KEY .................................................................................. 34
4.15 OK KEY ........................................................................................................................... 34
4.16 ESC KEY ..................................................................................................................... 35
4.17 ARROW KEYS ................................................................................................................... 35

4.18 ENTER KEY .................................................................................................................... 35
4.19 AUTO SET KEY ............................................................................................................. 35
4.20 ON/OFF KEY .................................................................................................................. 35
4.21 NAVIGATING THE HOT MENU ............................................................................................ 35
4.22 TOP & BOTTOM END CAPS ............................................................................................... 37
CHAPTER FIVE THEORY OF OPERATION .................................................... 38
5.1 ULTRASONIC MEASUREMENT OF BOLTS .............................................................................. 38
5.2 FEATURES OF THE MINIMAX ............................................................................................... 38
5.3 ULTRASONIC WAVES .......................................................................................................... 39
5.4 MEASUREMENT MODE ........................................................................................................ 39
CHAPTER SIX BOLT PREPARATION ............................................................ 40
6.1 USE OF ULTRASONIC COUPLANT ........................................................................................ 40
6.2 TRANSDUCER CONTACT REQUIREMENTS ............................................................................ 40
6.3 BOLT END REFLECTORS ..................................................................................................... 42
CHAPTER SEVEN TRANSDUCER SELECTION ............................................ 44
7.1 SELECTING THE TRANSDUCER ............................................................................................ 44
CHAPTER EIGHT MEASURING SYSTEM ZERO (CALIBRATION) ............... 45
8.1 INTRODUCTION .................................................................................................................. 45
8.2 CALIBRATION / ZERO MISNOMER ......................................................................................... 45
8.3 CREATING A GROUP TO DOCUMENT ZERO (CALIBRATION) DATA .......................................... 46
8.4 AUTO ZERO/CALIBRATION .................................................................................................. 54
8.5 USING A STANDARD BOLT .................................................................................................. 60
8.6 CALIBRATION / ZERO BARS & TRIPLE SIDED GLASS BLOCK ................................................. 74
CHAPTER NINE TEMPERATURE COMPENSATION ..................................... 91
9.1 PURPOSE .......................................................................................................................... 91
9.2 MANUAL MODE .................................................................................................................. 91
9.3 SEMI AUTOMATIC MODE ..................................................................................................... 92
9.4 AUTOMATIC MODE ............................................................................................................. 94
CHAPTER TEN BOLT MATERIAL CALIBRATION ......................................... 95
10.1 WHY CALIBRATE? ............................................................................................................ 95
10.2 VELOCITY CALIBRATION ................................................................................................... 95
10.3 STRESS FACTOR CALIBRATION .......................................................................................... 99
10.4 TEMPERATURE FACTOR CALIBRATION ............................................................................ 103
CHAPTER ELEVEN LOAD MEASURMENT .................................................. 106
11.1 CALCULATING LOAD FACTOR .......................................................................................... 106
11.2 CALIBRATING LOAD FACTOR (FIELD CALIBRATION) .......................................................... 108

11.3 PERFORMING A FIELD CALIBRATION ................................................................................ 109
CHAPTER TWELVE MEASUREMENT & WAVEFORM DISPLAY ............... 123
12.1 QUANTITIES OF MEASUREMENT ...................................................................................... 123
12.2 DISPLAY VIEW OPTIONS ................................................................................................. 124
12.3 ADJUSTING THE DISPLAY ................................................................................................ 128
12.4 GAIN .............................................................................................................................. 132
12.5 GATE ............................................................................................................................. 135
12.6 THRESHOLD ................................................................................................................... 138
12.7 INTERPRETING THE WAVEFORM ...................................................................................... 141
12.8 MANUALLY LOCATING THE ECHO .................................................................................... 142
12.9 AUTOMATIC ECHO OPTIMIZATION (AUTO SET) ................................................................. 144
12.10 UNLOADED LENGTH AND ELONGATION MEASUREMENTS ................................................ 147
CHAPTER THIRTEEN ADDITIONAL FEATURES ........................................ 148
13.1 QUALITY/CORRELATION (TRANSDUCER PLACEMENT) ...................................................... 148
13.2 CONTRAST ..................................................................................................................... 148
13.3 BACKLIGHT .................................................................................................................... 149
13.4 GRAPHICS OPTIONS (LOOK & FEEL) ................................................................................ 150
13.5 PULSE ........................................................................................................................... 152
13.6 PULSER VOLTAGE .......................................................................................................... 153
13.7 DAMPING ....................................................................................................................... 154
13.8 DIGITIZER ...................................................................................................................... 155
13.9 POLARITY ...................................................................................................................... 156
13.10 ALARM MODE ............................................................................................................... 157
13.11 KEY CLICK ................................................................................................................... 160
13.12 DATE & TIME ................................................................................................................ 160
13.13 UPGRADE GAUGE ........................................................................................................ 162
13.14 FREEZE & CAPTURE ..................................................................................................... 163
CHAPTER FOURTEEN DATA STORAGE – SETUP, EDIT, & VIEW FILES 165
14.1 INTRODUCTION TO GROUP (SPREADSHEET) FORMAT ....................................................... 165
14.2 CREATING A NEW GROUP ............................................................................................... 165
14.3 STORING A READING ....................................................................................................... 168
14.4 VIEWING STORED READINGS ........................................................................................... 169
14.5 DELETING GROUPS (FILES) ............................................................................................ 170
14.6 EDITING A GROUP (FILE) ................................................................................................ 173
14.7 CHANGING THE ACTIVE FILE - OPEN ................................................................................ 175
14.8 CLOSING AN ACTIVE FILE - CLOSE ................................................................................... 177
CHAPTER FIFTEEN SETUPS – CREATE, STORE, EDIT, & RECALL ....... 178
15.1 INTRODUCTION TO SETUPS ............................................................................................. 178

15.2 OPENING A SETUP ......................................................................................................... 178
15.3 SAVING A SETUP ............................................................................................................ 179
15.4 DELETING A SAVED SETUP ............................................................................................. 182
15.5 USING THE DEFAULT SETUP ........................................................................................... 184
15.6 SELECTING A LANGUAGE ................................................................................................ 185
CHAPTER SIXTEEN SOFTWARE, FILE TRANSFER, & UPGRADES ......... 187
16.1 COMPUTER SYSTEM REQUIREMENTS .............................................................................. 187
16.2 INSTALLING DAKVIEW ..................................................................................................... 187
16.3 COMMUNICATING WITH MINIMAX .................................................................................... 187
16.4 LINE POWER .................................................................................................................. 187
16.5 UPGRADING THE MINIMAX .............................................................................................. 187

1
CHAPTER ONE
INTRODUCTION
The Dakota Ultrasonics model MiniMax is used to measure the stretch (elongation,
load, stress and %strain) of a fastener under tension. This is accomplished
ultrasonically by sending an ultrasonic wave down the length of the fastener and
accurately measuring the change in transit time between an unloaded versus loaded
fastener/bolt, and calculating a physical stretch. The objective for using ultrasonics,
over conventional/mechanical methods is accuracy. Most conventional methods
refer to a torque value which has limited accuracy due to the coefficient of friction.
The coefficient of friction is difficult to determine, as it depends on the control and
application of lubrication.
The MiniMax avoids the coefficient of friction entirely, using the transit time of a
wave, Hooke’s law, and Young’s modulus to accurately calculate the stretch on a
bolt. Since the MiniMax cannot physically stretch a bolt, both
conventional/mechanical methods and the MiniMax are complimentary and used in
conjunction.
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 Corporation
1500 Green Hills Road, #107
Scotts Valley, CA 95066 USA
Telephone: [phone]
Facsimile: [phone]
www.dakotaultrasonics.com
1.1 General Disclaimer
The manual should be read and understood prior to using the MiniMax. This
operating manual provides the user with all the general information necessary to use
and adjust the designed features. However, this manual is not a certified
NDT/Bolting training course, nor is it intended to be one. Training, according to
company requirements, is recommended. The responsibility for proper use of the
instrument rests solely on the user.
1.2 Safety
Using the MiniMax while standing in water or in a wet environment can result in
serious electric shock, injury, and even death.
Operating the MiniMax with damaged or inadequate cables and power source can
result in serious electric shock, injury, and even death.

2
Failure to read this manual and understand the proper operation of the MiniMax can
result in inaccurate measurements, and lead to decisions which cause property
damage, personal injury, or even death.
Use of the MiniMax for any other purpose, or in any other manner than described in
this manual invalidates the warranty and can result in serious electric shock, injury,
and even death.
1.3 Warranty
The Dakota Ultrasonics MiniMax carries a two year limited warranty. The warranty
only applies to MiniMax units being operated as described in this manual. Software
and hardware failures of the unit will be repaired or replaced at Dakota Ultrasonics
discretion. Dakota Ultrasonics will not be held liable for any damage caused,
interruption of business, loss of profits, etc., resulting from such failures. Dakota
Ultrasonics will not be liable to repair or replace a unit, which has been damaged,
used inappropriately, or subject to unauthorized repair by the purchaser.

3
CHAPTER TWO
ABOUT THIS MANUAL
This chapter is intended to help you make the best use of this manual. Readers may
have different knowledge of ultrasonic bolt measurement and may find parts of this
manual repetitive or unnecessary.
2.1 New To Ultrasonics?
There are a variety of ultrasonic applications currently being utilized in today’s
industry. For example weld inspection, thickness measuring, immersion testing of
flaws, etc. The use of ultrasound to measure forces in fasteners is relatively new
compared to the previously mentioned traditional applications.
Ultrasonic measurement of bolts provides an extremely accurate means of
determining fastener load, provided the correct techniques are utilized. As a new
user, careful consideration of this entire manual is highly recommended.
2.2 New to fastener measurement?
Assuming you are familiar with ultrasonics, but unfamiliar with fastener measurement,
the chapters on transducer selection and the theory of operation can be skipped
entirely.
The MiniMax measures load on the fastener by measuring the amount the fastener
stretches. As load is applied to the fastener, it stretch’s just as a spring would
stretch. The stretch is proportional to the load while the load is less than the elastic
limit of bolt. By measuring the stretch of the fastener and knowing the physical
properties of the fastener, the load of the fastener can be calculated. The MiniMax
measures the fastener stretch by ultrasonically measuring the change in length.
Be sure to setup and experiment with a test fixture of some kind as a means of
becoming familiar with your MiniMax.
2.3 MiniMax Overview

Dakota Ultrasonics
4
In order to understand how to operate the MiniMax, it’s best to start off with an
understanding of what it is we’re looking at exactly. The MiniMax has a lot of great
features, tools, and flexibility to assist you with all of your bolting applications. Let’s
have a brief look at the screens you’ll be looking at most often:
A. Repeatability/Stability Indicator – Indicates the reliability of the measured
bolt length. When all the vertical bars are fully illuminated and the last digit on
the digital thickness value is stable, the MiniMax is reliably measuring the
same value on a consistent basis.
B. Battery Icon – Indicates the amount of battery life the MiniMax has
remaining.