UPGRADING THE MAXII ................................................................................................. 204
Page 7
Page 8
Page 9
CHAPTER ONE
INTRODUCTION
The Dakota Ultrasonics model MAX II 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 MAX II 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 MAX II cannot physically stretch a bolt, both conventional/mechanical
methods and the MAX II 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: (831) 431-9722
Facsimile: (831) 431-9723
www.dakotaultrasonics.com
1.1 General Disclaimer
The manual should be read and understood prior to using the MAX II. 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 MAX II while standing in water or in a wet environment can result in serious
electric shock, injury, and even death.
Operating the MAX II with damaged or inadequate cables and power source can
result in serious electric shock, injury, and even death.
Page 10
Failure to read this manual and understand the proper operation of the MAX II can
result in inaccurate measurements, and lead to decisions which cause property
damage, personal injury, or even death.
Use of the MAX II 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 MAX II carries a two year limited warranty. The warranty only
applies to MAX II 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.
Page 11
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 MAX II 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 MAX II
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 MAX II.
2.3 MAX II Overview
3
Page 12
Dakota Ultrasonics
In order to understand how to operate the MAX II, it’s best to start off with an
understanding of what it is we’re looking at exactly. The MAX II 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 MAX II is reliably measuring the same
value on a consistent basis.
B. Battery Icon – Indicates the amount of battery life the MAX II has remaining.
C. Temperature – Indicates the current temperature of either the temperature
sensor, or manual value entered.
4
Page 13
MAX II Bolt Tension Monitor
D. Alarm – Indicates that the alarm feature has been activated and currently in
use.
E. RF A-Scan Display (split screen) – Displays the radio frequency sound wave
reflection returned the opposite end of the bolt being measured. The RF view
displays both the positive and negative cycles.
F. Quantity – Displays the current quantity setting used (elongation, load, stress,
strain or time).
G. Digital Measurement – Display in inches, millimeters, KSI, KIPS, %strain,
time (nanoseconds).
H. Rectified A-Scan Display – Displays either the positive or negative half cycle
wave reflection returned from the opposite end of the bolt being measured,
depending on the polarity selected.
I. Time & Date – Feature to display either the time, date, or both time and date
on the main measurement screen.
J. Hot Menu items – We call this menu section our “hot menu”, as these items
are the most commonly adjusted features, requiring quick access from the
user. They can be displayed and scrolled by pressing the MEAS key at any
time. The MEAS key advances forward and the ESC key backwards to the
next hot menu item. Alternatively, the UP,DOWN, LEFT and RIGHT
arrow keys on the left button wheel can be used to either scroll through the
sub menu items, or advance to the next HOT MENU items list. There are 4
HOT MENU lists that contain the most commonly adjusted items from the
tabbed menus, and in the same order as the tabbed menus. Note: Some of
the lists contain multiple tabbed menu items in order to condense the number
of HOT MENU lists.
K. Units – Displays the current measurement units being used (English, Metric).
L. Gain & Step Size – The gain and increment step size can be continuously
used and adjusted at any time using the UP and DOWN arrow keys on
the right button wheel to scroll the value, and the GAIN key to activate the
Digit Edit screen to adjust the step size.
M. Scan Bar – Another view of bolt length in a deflection style horizontal bar.
This is a visual tool that would enable the user the ability to see the length
from a graphics perspective.
N. Large Digital Measurement – Display in inches, millimeters, KSI, KIPS,
%strain, time (nanoseconds).
O. Feature Status Bar – Indicates the features currently enabled and in use in
P. Temperature – Depending on the display view selected full/split screen, the
temperature will be displayed in either of two different locations on the screen.
Q. Digital Measurement – In full screen view, the measurement will be displayed
in either of two different locations (full/split screen).
R. RF A-Scan Display (full screen) – Displays the radio frequency sound wave
reflection returned the opposite end of the bolt being measured. The RF view
displays both the positive and negative cycles.
2.4 Top & Submenu Reference
The following table is a quick menu reference guide. The MAX II has 11 top level
menu titles, and multiple submenu items as illustrated below. The MAX II also has 4
‘hot menu’ subsets of the same menu structure. These are the most commonly
adjusted submenu items from each of the top level menus. They can be quickly
accessed from the main measurement screen by pressing the LEFT and RIGHT
arrow keys multiple times using the left button wheel, and pressing the UP and
DOWN arrow keys on the left button wheel to select the appropriate submenu item.
Refer to Chapter Four for additional definitions and information on the keypad and
menu items.
1st Main Hot Menu
Additional Hot Menus
Note: “Log” is also listed in the 1st main Hot Menu, and is used to access data storage if no log file is
currently open, or display log or grid file if open.
Start >>
CAL MATL GEOM DISP TUNE GATES AUTO SETUP
ZERO MODE UNITS QUANTITY VIEW GAIN POLARITY AUTO SET OPEN
ZERO TYPE LOAD FACTOR BRIGHTNESS PULSE GATE 1 APPROX LEN SAVE
MEASURE
ZERO
LOAD CAL
MODE
LOAD CAL
CALC
WIDTH GATE 3 LANGUAGE
RECT WAVE THRESHOLD 3
DETECT MARK
VELOCITY LOAD OFFSET COLORS PULSER
VOLTAGE
STRESS
FACTOR
TEMP COEF EFFECTIVE
AREA DIM DAMPING GATE 2 DEFAULT
DELAY DIGITIZER THRESHOLD 2
LEN
THRESHOLD 1 MEASURE
MODE
DELETE
SETUP
6
Page 15
>> End
DATA UTILS XFER
NEW TEMP MODE BACKUP
SETUPS
EDIT ALARM COPY DATA
OPEN ALARM LOW COPY
SCREENS
CLOSE ALARM HIGH UPGRADE
GAUGE
MAX II Bolt Tension Monitor
DELETE ONE
FILE
DELETE ALL
DATA
SET DATE ABOUT
SUMMARY SHOW DATE
ANALOG
OUTPUT
KEY CLICK STORAGE
CAPTURE TO
FILE
7
Page 16
CHAPTER THREE
QUICK START GUIDE
3.1 Overview
This section demonstrates the basic procedures for setting up and measuring bolts
using the MAX II. More in depth explanations pertaining to the individual functions
and features can be found in the chapters that follow.
Here we go!
3.2 Getting the MAX II ready
Making all the connections
In order to get the MAX II ready for operation; the following connections must
be made:
1) Remove the MAX II from the carrying case.
2) Connect the transducer cable to the transducer, and plug the lemo
connector into the gauge.
3) If a temperature sensor is being used, connect the sensor to the MA X II.
3.3 Setting up the MAX II
Please Read: In this section the MAX II will be setup in its simplest form. Remember
this is only a quick start guide to get the user up and measuring bolts. Before we
setup the gauge to measure basic elongation, the following assumptions must be
made: A preset material type will be used. The user will not be re-measuring the
fasteners at a later date to monitor relaxation of the joint over time. This eliminates
the need for an instrument zero/calibration. All these assumptions will be answered
and explained in detail in the chapters that follow.
Selecting the Quick Start Setup
8
Page 17
MAX II Bolt Tension Monitor
1) Press the ON/OFF key to power up the MAX II.
2) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right and the ESC key multiple times to tab left until
the SETUP menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel.
3) Use the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the sub menu items until OPEN is highlighted.
4) Press the ENTER key to display the list of setups.
5) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the setup list until the QUICK START setup is
highlighted.
6) Press the ENTER key to display the confirmation screen.
7) Press the OK key to select the setup and return to the menu screen, or ESC
to cancel the selecting the setup.
9
Page 18
Dakota Ultrasonics
Selecting the Units
Note: The Quick Start setup, selected in the previous section, automatically
defaults to english units – inches. Follow the procedure below to change the
units to metric, if needed.
1) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the MATL menu is highlighted and displaying the
submenu items. Alternatively, press the MENU key once, followed by
pressing the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the tabbed menus.
2) Use the UP and DOWN arrow keys to scroll through the sub menu items
until UNITS is highlighted.
3) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll through the unit options IN (inches), IN HR (inches hi
resolution), MM (millimeters), and MM HR (millimeters hi resolution).
Note: The high-resolution options display an additional digit of resolution to the
measurement. This mode is typically used when measuring very short bolts
with very little elongation.
Selecting the Material Type
10
Page 19
MAX II Bolt Tension Monitor
This section allows the user the ability to select a material from a list of preset
material types. Keep in mind that we are measuring elongation only. If your
material is not in the list, select a similar material type. When measuring in
elongation mode, the measurement consists of a difference equation only
(Loaded Length – Unloaded Length = Length). Therefore, it doesn’t matter if
the ultrasonic length is different from the actual physical length, because the
Length will be the same. Example: 2.0080” physical loaded length – 2.0000”
physical unloaded length = 0.0080” Length which is equivalent to 2.1080”
ultrasonic loaded length – 2.1000” ultrasonic unloaded length = 0.0080”
Length.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until TYPE is highlighted.
2) Press the ENTER key to display the list material types.
3) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the material list until the appropriate type is
highlighted.
4) Press the ENTER key to display the confirmation screen.
5) Press the OK key to select the type and return to the menu screen, or ESC
to cancel selecting the material type.
11
Page 20
Dakota Ultrasonics
3.4 Creating a New Group to Store Measurements
Now that the MAX II is all setup, this section will explain how to get started measuring
unloaded initial lengths. In order to do this, we need to create a group that contains
bolts. A group can have up to 250 bolts, each bolt containing 1 reference length (LREF), and up to 51 elongations. Keep in mind that the MAX II uses a group to store
measurements and all gauge settings at the time of measurement.
Creating a Group Name
1) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right, and the ESC key multiple times to tab left,
until the DATA menu is highlighted and displaying the submenu items.
Alternatively, press the MENU key once, followed by pressing the LEFT and RIGHT arrow keys multiple times using the left button wheel to
scroll the tabbed menus.
Note: Pressing the key will automatically open the DATA tabbed menu.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until NEW is highlighted.
3) Press the ENTER key to display the New Group Edit Box.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NAME is
highlighted.
5) Press the ENTER key to activate the Alpha Edit Box.
12
Page 21
MAX II Bolt Tension Monitor
6) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to highlight the appropriate alpha characters.
7) Press the ENTER key to select a character and advance to the next field of
the Group Name.
8) Use the CLR key to backspace if necessary.
9) Repeat steps 6 - 8 until the Group Name is completed.
10) Press the OK key to save the Group Name and return to the Group List
Items menu, or ESC to cancel entering the Group Name.
Creating a Group Note
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NOTE is
highlighted.
13
Page 22
Dakota Ultrasonics
2) Press the ENTER key to activate the Alpha Edit Box.
3) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to highlight the appropriate alpha characters.
4) Press the ENTER key to select a character and advance to the next field of
the Group Note.
5) Use the CLR key to backspace if necessary.
6) Repeat steps 3 - 5 until the Group Note is completed.
7) Press the OK key to save the Group Note and return to the Group List
Items menu, or ESC to cancel entering the Group Note.
Selecting the Number of Bolts in the Group
Note: A group can contain up to 250 bolts. There must be at least 1 bolt in a
group.
14
Page 23
MAX II Bolt Tension Monitor
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NUM BOLTS
is highlighted.
2) Press the ENTER key to display the Digits Edit Box.
3) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the highlighted value.
4) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the digit locations.
5) Repeat steps 3 & 4 until the NUM BOLTS value is correctly displayed.
6) Press the OK key to save the NUM BOLTS and return to the Group List
Items menu, or ESC to cancel entering the NUM BOLTS.
Note: If a number greater than 250 is entered, an error message box “VALUE
IS OUT OF RANGE” will be displayed.
7) Press the OK key to display the Digits Edit Box and re-enter the NUM BOLTS.
8) Press the OK key to save the NUM BOLTS and return to the Group List
Items menu, or ESC to cancel entering the NUM BOLTS.
Selecting the Number of Readings Per Bolt
Note: A bolt can have up to 51 possible measurements and 1 initial length (L-
REF). There must be at least one reading per bolt.
15
Page 24
Dakota Ultrasonics
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NUM READS
is highlighted.
2) Press the ENTER key to display the Digits Edit Box.
3) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the highlighted value.
4) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the digit locations.
5) Repeat steps 3 & 4 until the NUM READS value is correctly displayed.
6) Press the OK key to save the NUM READS and return to the Group List
Items menu, or ESC to cancel entering the NUM READS.
Note: If a number less than 1 or greater than 51 is entered, an error message
box “VALUE IS OUT OF RANGE” will be displayed.
7) Press the OK key to display the Digits Edit Box and re-enter the NUM READS.
8) Press the OK key to save the NUM READS and return to the Group List Items menu, or ESC to cancel entering the NUM READS.
If there’s not enough memory available to create the group, an error message
box “NOT ENOUGH MEMORY” will be displayed. Press the OK or ESC key to
16
Page 25
MAX II Bolt Tension Monitor
return to the Group List Items menu. It may be necessary to free some
memory in the MAX II at this time.
Selecting the Starting Bolt Number
Note: Depending on the application and layout of the project, the user won’t
always want the starting bolt to be 1. This feature allows the user to define
what the starting number will be.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until START BOLT NUM is highlighted.
2) Press the ENTER key to display the Digits Edit Box.
3) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the highlighted value.
4) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the digit locations.
5) Repeat steps 3 & 4 until the START BOLT NUM value is correctly
displayed.
6) Press the OK key to save the START BOLT NUM and return to the Group List Items menu, or ESC to cancel entering the START BOLT NUM.
17
Page 26
Dakota Ultrasonics
Note: If a value is enter that is greater than the maximum number of bolts
allowed per group (250), an error message box “VALUE IS OUT OF RANGE”
will be displayed.
7) Press the OK key to display the Digits Edit Box and re-enter the START BOLT NUM.
8) Press the OK key to save the START BOLT NUM and return to the Group
List Items menu, or ESC to cancel entering the START BOLT NUM.
Selecting the Auto Increment Direction
The Auto Increment feature gives the user the ability to specify which direction
to advance the cursor after storing a reading.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until INCR. DIR is
highlighted.
2) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to toggle the Increment direction NONE, NORTH, EAST, SOUTH, or WEST.
3) When the correct Increment direction is dis played, continue on to the next
section “Saving the Group”.
18
Page 27
MAX II Bolt Tension Monitor
Saving the Group
Once all the parameters are set, the user has the option of saving or canceling
the new group.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until CREATE NEW GROUP? is highlighted.
2) Press the ENTER key to accept the group parameters, and activate the
confirmation screen.
3) Press the OK key to save the New Group, or the ESC key to cancel the New Group setup and return to the DATA menu.
4) Press the MEAS key to return to the measurement screen to begin
measuring reference lengths.
3.5 Setting the Approximate Length
In order to utilize the AUTO SET feature of the MAX II, when measuring reference
lengths, the MAX II has to know where to start looking for the detection. We can
accomplish this by entering an approximate length into the gauge. The MAX II will
automatically take the value entered and scan +/- 5% in both directions of the
approximate length for the detection signal. The approximate length is a very
valuable feature that can be used to pin point a specific detection area. This feature
will be further discussed later in the manual.
Setting the Approximate Length using the Hot Menus
19
Page 28
Dakota Ultrasonics
1) Press the MEAS key once to activate measure menu items. Press the MEAS key multiple times to move down and the ESC key multiple times to
move up, until the ALEN cell is highlighted. Alternatively, press the UP
and DOWN arrow keys multiple times using the left button wheel.
2) Press the ENTER key to display the Digits Edit Box.
3) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the highlighted value.
4) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the digit locations.
5) Repeat steps 3 & 4 until the ALEN value is correctly displayed.
6)
Press the OK key to return to the measurement screen, or ESC to cancel
entering the ALEN.
The user can also access and set the approximate length from the tabbed menus.
However, this method is more tedious than making the adjustments using the Hot
Menus. The procedure using the tabbed menus is outlined below:
Setting the Approximate Length using the Tabbed Menus
20
Page 29
MAX II Bolt Tension Monitor
1) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right, and the ESC key multiple times to tab left,
until the AUTO menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until APPROX. LEN. is
highlighted.
3) Press the ENTER key to display the Digits Edit Box.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the highlighted value.
5) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the digit locations.
6) Repeat steps 4 & 5 until the Approx. Len. value is correctly displayed.
7) Press the OK key to set the Approx. Len. and return to the menu screen, or ESC to cancel entering the Approx. Len..
8) Finally, press the MEAS key to return to the measurement screen and begin
measuring reference lengths.
21
Page 30
Dakota Ultrasonics
3.6 Measuring Reference Lengths
At this point, the MAX II is setup and ready to start measuring reference lengths.
We’ve already setup a bolt group to store the reference length data, and now need to
display the group storage locations prior to making measurements.
Storing a Reading
1) Press the MEAS key once to activate measure menu items. Press the
MEAS key multiple times to move down and the ESC key multiple times to
move up until the LOG cell is highlighted. Alternatively, press the UP
and DOWN arrow keys multiple times using the left button wheel.
Note: Pressing the key will automatically open the Group View Box.
2) Press the ENTER key to display the Group View Box.
3) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to scroll the target cell cursor to the desired storage location.
Note: The approximate lengths must always be located in the first column A for
all bolts in the group.
4) Place a small amount of couplant on the transducer and attached it to the
bolt. Make sure that the transducer is seated so that there is no couplant
22
Page 31
MAX II Bolt Tension Monitor
layer creating a gap between the transducer and bolt. This can be
accomplished by rotating the transducer clockwise and counter clockwise
while applying a very small amount of pressure to seat the transducer firmly
against the bolt.
Important Note: Always be sure to place the transducer in the same exact
location if it will be removed in between reference lengths and elongation
measurements. This will eliminate any potential sound path error caused by
moving the transducer to a completely different location on the bolt, thus
causing potentially erroneous measurements. Be consistent and as methodical
in your methods as possible. This will help to avoid transducer placement
errors.
5) Press the AUTO SET key, located in the bottom left corner of the keypad, to
locate the detection point, or end of the bolt.
6) Press the ENTER key to save the current approximate length in the
highlighted cell location.
Note: If the measurement was saved in error, press the CLR key at anytime to
clear the stored reading and re-measure using the steps 4 – 6 above.
Note: The Group View Box can be aborted at any time by pressing the MEAS
key.
3.7 Measuring Elongations
Now that the reference lengths have been measured and saved, we’re ready to start
measuring elongation values. We’ll start off by assuming the bolt has been stretched
or tightened, the transducer has been once again coupled to the bolt in the same
location as before, and we’re ready to measure the elongation as follows:
Measuring an Elongation
23
Page 32
Dakota Ultrasonics
Important Note (recap): Always be sure to place the transducer in the same
exact location if it will be removed in between reference lengths and elongation
measurements. This will eliminate any potential sound path error caused by
moving the transducer to a completely different location on the bolt, thus
causing potentially erroneous measurements. Be consistent and as methodical
in your methods as possible. This will help to avoid transducer placement
errors.
1) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to scroll the target cell cursor to the desired storage location.
Note: Elongation values must be stored in column B - ZZ.
Note: Do not press the AUTO SET key, while measuring elongation’s, as this
activates a high speed mode used specifically with our shut-off box. The AUTO
SET feature is only used when measuring reference lengths. If the AUTO SET
key is accidentally pressed, press it again to turn the high speed mode off.
2) Press the ENTER key to save the current elongation in the highlighted cell
location.
Note: If the measurement was saved in error, press the CLR key at anytime to
clear the stored reading and re-measure using steps 1 & 2 above.
3) Continue to repeat this process until all the elongation measurements have
been completed.
Note: The Group View Box can be aborted at any time by pressing the MEAS
key.
24
Page 33
CHAPTER FOUR
KEYBOARD, MENU, & CONNECTOR REFERENCE
4.1 Menu Key (Operation & Sub Menus)
The Menu key activates the primary menu structure containing 11 menu tab groups.
These tab groups then contain sub menu items, or functions. The sub menu items
have been organized in tab groups according to how closely they are related to the
individual tab group names. Let’s first get familiar with how to move around in these
tabs before continuing on to the sub menu functions. This procedure is outlined
below:
25
Page 34
Dakota Ultrasonics
Activating and Getting Around in the Menu Items
1) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right, and the ESC key multiple times to tab left
until the desired tab group is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel. The tab groups are illustrated above (A).
Now that you’re familiar with activating and moving amongst the tab groups, let’s
have a look at how to move around in the sub menu items as follows:
Getting Around in the Sub Menu Items
1) Use the UP and DOWN arrow keys on the left button wheel to scroll
through the sub menu items until the desired function is highlighted. The
sub menu items are illustrated in the diagram above (B).
2) Depending on which function is highlighted, use the LEFT and RIGHT
arrow keys on the right button wheel to scroll the options, or the ENTER key
to activate the Digit Edit and List Box options.
The sections to follow will provide the user with an explanation of the sub menu
functions:
26
Page 35
MAX II Bolt Tension Monitor
4.2 CAL – Menu
ZERO MODE:
micrometer is zeroed. There are three zero mode options available in the MAX II –
FIXED, ONE POINT, TWO POINT and AUTO. Selecting the proper mode is
dependent on the application requirements, but the most convenient mode of
preference is - AUTO. Refer to page 48, for an explanation of this important
procedure.
ZERO VALUE: Depending on the Zero Mode selected above, the actual zero value
will be calculated and displayed in this sub menu item. The user can edit this value
at anytime from this sub menu item. Refer to page 48 for a further explanation.
MEASURE ZERO: Once the Zero Mode has been selected above, this function
displays and calculates the actual measurement screen containing the known
physical length, velocity, and temperature coefficient of the calibration standard
versus the ultrasonic length. . Refer to page 48 for a further explanation.
LOAD CAL MODE: Enables and disables the field calibration feature of the MAX II.
This is used to compare known and ultrasonic loads. Refer to page 111 for a further
explanation.
LOAD CAL CALC: This feature is used to calculate a linear regression or vector
curve, once the Load Cal Mode is enabled and known and ultrasonic loads have
been entered and ultrasonically measured. If the regression option was selected in
Load Cal Mode, a correction load offset and load factor will be calculated. If the
vector option was selected, a load factor will be calculated and the offset will be set to
zero. Refer to page 111 for a further explanation.
The MAX II is zeroed in much the same way that a mechanical
4.3 MATL (material) – Menu
27
Page 36
Dakota Ultrasonics
UNITS: Toggle between English and Metric units and multiple resolutions for each
unit ( IN - .0001, INHR - .00001, or MM - .001, MMHR - .0001 ), Using the
abbreviation HR to represent High Resolution.
TYPE: Select the bolt material type from a preset list of material types. Each type
contains a velocity, stress factor, and temperature factor. When a type is selected,
these values are displayed in the sub menu items below and can be edited by the
user at anytime.
VELOCITY: This feature allows the user to edit the material velocity at anytime.
Once a material type is selected, the velocity of the selected material type is stored in
this sub menu item and can be edited a by the user if necessary.
STRESS FACTOR: This feature allows the user to edit the stress factor at anytime.
Once a material type is selected, the stress factor of the selected material type is
stored in this sub menu item and can be edited by the user if necessary. Refer to
page 102 for further info.
TEMP COEF: This feature allows the user to edit the material temperature coefficient
at anytime. Once a material type is selected, the temperature coefficient of the
selected material is stored in this sub menu item and can be edited by the user if
necessary. Refer to page 106 for further info.
4.4 GEOM (geometry) – Menu
QUANTITY:
STRESS, and % STRAIN. Refer to page 127 for further info.
LOAD FACTOR: The conversion factor from elongation to Load. This value is
typically determined by performing a field calibration and running a regression or
vector using the MAX II or utility software. Alternatively, the load factor can be
determined using the bolt calculator in the utility software. However, if extreme
accuracy is required, performing a field calibration is a must. This sub menu item
enables the user to edit the factor at anytime. Refer to page 109 for further info.
LOAD OFFSET: Normally the Load Offset is set to zero. However, when a field
calibration is performed and regression calculated a small offset (y intercept) will
result. This value is a constant added or subtracted from the measurement, and will
result in correction to the load quantity. This sub menu item enables the user to edit
the offset value at anytime. Refer to page 109 for further info.
AREA:
stress. Set to zero if the user is not measuring the quantity in terms of stress. This
Selectable units of measure in terms of TIME, ELONGATION, LOAD,
The cross sectional area of the fastener being measured. Used to calculate
28
Page 37
MAX II Bolt Tension Monitor
sub menu item enables the user to edit the area at anytime. Refer to page 109 for
further info.
EFFECTIVE LENGTH: The length of the region of the fastener under stress (the
distance between the nut plus some amount of additional stress that occurs in the
head and nut(s) of the fastener). This sub menu item enables the user to edit the
effective length at anytime. Refer to page 109 for further info.
4.5 DISP (display) – Menu
VIEW: Selectable RF wave, RECT (rectified), and DIGITS (large digits) views. Refer
to page 128 for further info.
BRIGHTNESS: Blanview high speed color display. An arbitrary scale of 1-20 has
been implemented, with the brightest setting at 20. Refer to page 157 for further info.
COLORS: Provides the user with 12 different color schemes to select from. There
are two schemes for each main color option. Refer to page 158 for further info.
DIM: Allows the user to conserve battery life by diming the display after idle for a
specific amount of time – OFF, 30, 60, 90, 120 seconds. Once dimmed, a single
press of any key will restore the screen brightness. Refer to page 160 for further info.
DELAY: Provides the user the ability to change where the left side of the display
window starts according to time which is convert to a length, in english or metric
units. Refer to section 12.3 for further info.
WIDTH:
measurement area. It functions a lot like a zoom on a camera. Refer to section 12.3
for further info.
RECT WAVE: This option provides the user an outlined or filled view option when
the display setting is in RECT (rectified) wave mode only. Refer to page 128 for
further info.
DETECT MARK:
waveform: Line, Box, Dots, None. Offers the user a graphics preference on how
they prefer to view the detection on the waveform.
Provides the user the ability to change the overall size of the viewable
Selectable graphics option for the point of detection on the
29
Page 38
Dakota Ultrasonics
4.6 TUNE – Menu
GAIN:
with the attenuator feature above. This feature is used to increase/decrease the
power or amplitude of the signal. This might easily be considered as similar to
turning the volume up or down on a stereo receiver. Refer to page 139 for further
info.
PULSE: The DFX-8 has an adjustable pulse width for both high penetration and
resolution applications. The pulse width refers to the duration of time the pulser is
on. There are three different types of pulsers built into the MAX II – Spike, Square
Wave, and Tone Burst with adjustable voltage options of 100-400 volts and select
settings of Spike, Thin, Wide, HV Spike, HV Thin, HV Wide, TB 10MHz, TB 5MHz,
TB 2MHz, and TB 1MHz. Refer to page 171 for a further explanation.
PULSER VOLTAGE: Adjustable voltage of 100-400 volts, depending on the pulser
option selected. The standard setting is 150 volts. This enables the MAX II to offer
greater penetration for difficult material types, or increased resolution on noisy
materials. Refer to page 163 for a further explanation.
DAMPING: Provides the user with multiple input impedances to match the
impedance of the transducer, and optimized overall transducer performance. Refer
to page 165 for further info.
DIGITIZER: Increases the measurement resolution by 2x or 4x by increasing the
number of shots/samples. The higher the sample digitizer rate, the better the
resolution, but the slower the update rate/speed and visa versa. Refer to page 163
for a further explanation.
The MAX II has 100dB gain range from (-30 to 70 dB), used in conjunction
4.7 GATES – Menu
POLARITY: The MAX II operates on a zero crossing detection principal. This
feature toggles which stroke of the cycle the crossing detection uses, either positive
or negative. Refer to 13.10 for further info.
30
Page 39
MAX II Bolt Tension Monitor
GATE 1: Gates allow the user to view a specific measurement range, or sections of
the waveform, and ignore others. The Gate1 feature adjusts the start of the gate,
according to time/distance. Gate 1 can be used in all pulse-echo and echo-echo
measurement modes. Refer to page 143 for further info.
THRESHOLD1:
of the signal must reach or exceed the threshold level before a measurement is
detected. Refer to page 143 for further info.
GATE 2:
specific distance from the first detection point found inside of the boundaries of the
Gate 1 settings. If no detection is found, the Gate1 width value is used as a starting
value for Gate2. Refer to page 143 for further info.
THRESHOLD2: Enables the user to set the sensitivity level of Gate2. The amplitude
of the signal must reach or exceed the threshold level before a measurement is
detected. Refer to page 143 for further info.
GATE 3: Provides the user with the ability to delay the starting point of Gate3, a
specific distance from the first detection point found inside of the boundaries of the
Gate 2 settings. If no detection is found, the Gate2 width value is used as a starting
value for Gate3. Refer to page 143 for further info.
THRESHOLD3: Enables the user to set the sensitivity level of Gate3. The amplitude
of the signal must reach or exceed the threshold level before a measurement is
detected. Refer to page 143 for further info.
Provides the user with the ability to delay the starting point of Gate2, a
Enables the user to set the sensitivity level of Gate1. The amplitude
4.8 AUTO – Menu
AUTO SET:
viewable display area. Used when measuring reference lengths only. Refer to
section 12.9 for further info.
APPROX LEN:
length of the fastener must be entered. The approximate length gives the MAX II
some idea of where to turn on the receiver and look for the detection, or end of the
bolt. This sub menu item enables the user to edit the effective length at anytime.
Refer to section 12.9 for further info.
MEASURE MODE: Used to select the measurement mode for different application
requirements. The mode options are P-E (pulse-echo), E-E (echo-echo), or E-EV
(echo-echo-echo). Refer to page 143 for further info.
Automatically locates the detection point if the measurement is out of the
In order for the user to use the Auto Set feature, an approximate
31
Page 40
Dakota Ultrasonics
4.9 SETUP – Menu
OPEN:
These setups can be recalled and used at any time. Refer to page 191 for further
info.
SAVE: Provides the user with the ability to save a custom setup that has been
modified or created by the user. Refer to page 192 for further info.
DELETE: Provides the user with the ability to delete specific setups previously save
in memory. Refer to page 195 for further info.
DEFAULT SETUP: Loads a basic default setup. Use only as a last resort when the
setups in the MAX II have been corrupted and a computer is not accessible. Refer to
page 197 for further info.
LANGUAGE: Provides the user the ability to select different languages for the MAX
II. Refer to page 198 for further info.
Displays a list of factory and user defined setups currently stored in memory.
4.10 DATA – Menu
NEW: Allows the user the ability to create a new alpha numeric grid, or sequential
log file with auto identifiers. It is equipped with custom parameters, rows, and
columns depending on the user’s application reporting requirements. Refer to page
177 for further info.
EDIT: Gives the user the ability to change parameters of grid or sequential file
previously saved. Note: Pre-defined coordinates cannot be changed once they have
been created. Refer to page 186 for further info.
OPEN:
files that currently exist in memory, from a list of grids. Refer to page 188 for further
info.
CLOSE:
log file. Refer to page 190 for further info.
This function provides the user with the ability to recall grids or sequential log
Provides the user the ability to close a currently opened grid or sequential
32
Page 41
MAX II Bolt Tension Monitor
DELETE ONE FILE: This function provides the user with the ability to delete one
individual grid or sequential log file from a list of multiple grids/files previously saved
in memory. Refer to page 183 for further info.
DELETE ALL DATA: This function provides the user with the ability to delete all files
currently stored in memory. Refer to page 184 for further info.
SUMMARY: Provides the user with an overall summary of the current data group
open/active. Refer to page 184 for further info.
4.11 UTIL (utilities) – Menu
TEMP MODE: This sub menu item enables the user to select the automatic
temperature compensation mode (manual, semi-auto, and auto). This feature is only
available to those units purchased with the automatic temperature compensation
option and probe. Note: Contact Dakota for information on upgrading the MAX II.
Refer to Error! Reference source not found. for further info.
ALARM: Toggles alarm mode on, off, or audible. Refer to page 168 for further info. ALARM: Toggles alarm mode on, off, or audible. Refer to page 168 for further info.
ALARM LOW: Gives the user the ability to set the LO limit parameter. If the
measurement falls below this value, a red light will illuminate and sound the internal
beeper. Refer to page 168 for further info.
ALARM HIGH: Gives the user the ability to set the HI limit parameter. If the
measurement exceeds this value, a red light will illuminate and sound the internal
beeper. Refer to page 168 for further info.
ANALOG OUTPUT:
is determined by the PRF setting. Refer to page 170 for further info.
KEY CLICK: Gives the user the ability to set the level of the key press beeper OFF, QUIET, or LOUD. Refer to page 171 for further info.
SET DATE: Gives the user the ability to set the internal date and time stamp in the MAX II. Refer to page 172 for further info.
SHOW DATE:
measurement screen. Refer to page 172 for further info.
Gives the user the ability display the time, date or both in the main
Proportional outputs (amplitude or distance), 0-10 volts. Speed
33
Page 42
Dakota Ultrasonics
4.12 XFER (transfer) – Menu
BACKUP SETUPS:
memory card to the other memory card, depending on the current internal/external
setting of Storage (current device being used to store data), located in the XFER
menu. Refer to page 202 for further info.
COPY DATA:
internal or external SD memory card to the other memory card, depending on the
current internal/external setting of Storage (current device being used to store data),
located in the XFER menu. Refer to page 202 for further info.
COPY SCREENS:
external SD memory card to the other memory card, depending on the current
internal/external setting of Storage (current device being used to store data), located
in the XFER menu. Refer to page 202 for further info.
CAPTURE TO FILE: Enables the user the ability to enable screen captures to .tiff
files, and used in conjunction with the FREEZE key. Refer to page 174 for further
info.
UPGRADE GAUGE: Enables the user the ability to upgrade the MAX II to the most
current firmware revision. Refer to page 173 for further info.
STORAGE: Enables the user to select which SD memory card to use for storage.
Note: if no card exists in the external reader slot, this option will be grayed out and
inactive. Refer to page 201 for further info.
ABOUT:
MAX II software version. Refer the Dakota Ultrasonics web site for information on
the latest firmware versions available for download.
Enables the user to copy all, or individual grid/log files from either the
Provides the user with Dakota Ultrasonics contact information and the
Copies setup files from either the internal or external SD
Copies screen capture (.tif’s) files from either the internal or
4.13 ON/OFF Key
The ON/OFF key simply powers the unit either ON or OFF. Note: Unit will
automatically power off when idle for 5 minutes. All current settings are automatically
saved prior to powering off.
4.14 FREEZE Key
34
Page 43
MAX II Bolt Tension Monitor
The FREEZE key is used to freeze the display for evaluation/review of what’s
currently on the display. It is also used in conjunction with the CAPTURE feature to
save the current display to a .tif (tagged image) graphic file that can be opened using
any graphics viewer.
4.15 SETUPS Key
The PEAK key is a feature used in the flaw detector portion of the MAX II, and is not
used in the thickness gauge.
4.16 AUTO SET Key
The AUTO SET is an automatic measurement routine that attempts to locate the
detection and set all the scope parameters of the MAX II.
4.17 DATA Key
The DATA key opens the tabbed data menu, allowing a user to efficiently create a
new group file of bolts for storage.
4.18 STORE Key
The STORE key displays the current group opened in split screen mode. If no group
file is currently open, pressing this key will open the tabbed data menu in order create
a new, or open an existing group file for storage.
4.19 CLEAR Key
The primary functions of the CLR key, is to clear a measurement from a group file
cell location, and backspace in an Alpha Edit Box.
4.20 MEAS (measurement mode) Key
The MEAS key puts the MAX II into its primary mode of operation. In this mode, the
user has a complete view of the waveform, hot menu items, and measurement.
35
Page 44
Dakota Ultrasonics
4.21 OK Key
The primary function of the OK key is confirmation of a change or selection. The OK
key also toggles between full or split screen view while in the main measurement
screen. If the MAX II is displaying a data group, the OK key toggles an advance to
row number option.
4.22 ESC Key
The ESC key is used in the MENU, MEAS, and EDIT functions as a back or escape
function. If the MAX II is displaying a group file, the OK key toggles the display view
options: Digits, RF, RECT views.
4.23 Wheel Keys
The Wheel Keys are used to navigate through the menus, increase/decrease values,
and toggle specific function keys.
4.24 ENTER key
The ENTER key is used in the overall menu selection process, to activate list and
edit boxes, display and save measurements to a group file location.
4.25 Navigating the Hot Menus
36
Page 45
MAX II Bolt Tension Monitor
The diagram above is a screenshot of all 4 “Hot Menus” in the MAX II. The Hot
Menu’s contain all the most regularly adjusted features from each tabbed menu, in
the exact order of the tabbed menus themselves. Some of the menus have been
combined into a single Hot Menu in order to reduce the number of hot menus. The
primary purpose of the design was to provide the user with an efficient way to make
adjustments on the fly, while continuing to have visibility of the A-Scan display. The
following procedure outlines the steps to navigate and make adjustments as follows:
Navigating Hot Menus
1) Using the left button wheel, press the LEFT and RIGHT arrow keys to
scroll through the 4 individual Hot Menus, and the UP and DOWN
arrow keys to scroll through the Hot Menu items. Alternatively, the MEAS & ESC keys can be used to scroll through the Hot Menu items.
2) Press the
button wheel to toggle the value or status.
Note: This is a coarse adjustment. It’s the fastest and easiest way to
increment, decrement, or toggle the status however it does so in coarse steps.
Pressing the ENTER key will allow the user to enter a specific target value.
This procedure above is universal for navigating through and selecting all
the features in the Hot Menus.
LEFT and RIGHT arrow keys multiple times on the right
37
Page 46
4.26 Top & Bottom End Caps
The top & bottom end panels are where all connections are made to the MAX II. The
diagram above shows the layout and description of the connectors:
Transducer Connector
Refer to Diagram: The transducer connector is a board mounted and shielded
LEMO “00”.
Temperature Sensor Connector
Refer to Diagram: The temperature sensor connector is a Shielded custom 5 pin
Lemo “1”.
Battery Covers (backup)
Refer to Diagram: The emergency battery backup disks are the large round disks
shown in the diagram. Each compartment stores three 3 AA cell batteries. A polarity
diagram is shown on the back label of the gauge. Use caution to be sure the
batteries are inserted correctly. Note: Rechargeable batteries can be used, however
they must be recharged outside of the unit in a standalone battery charger.
USB Type B Connector
Refer to Diagram: The USB connector is a common type B connector found on a
variety of electronic devices. This port will be used to transfer stored grid/log files,
captured screen shots, etc. This connector will also be used to upgrade the MAX II
with the latest version of firmware (gauge software). The cable supplied with the
MAX II is USB type A to USB type B.
RS-232 Serial Connection (LEMO 1 – 5 pin)
Refer to Diagram: The RS-232 connector is a 5 pin female Lemo 1 connector. It is
designed to connect directly from the MAX II to a standard AT serial port on a PC,
and will be used in conjunction with our proprietary java application software called
“Remote Commander”. The primary purpose of the Remote Commander is for
system integration to be controlled by a PC. An accessory 9 pin female serial to
Lemo 1 - 5 pin male cable will be required to use this feature, and is not included in
the standard kit.
38
Page 47
MAX II Bolt Tension Monitor
Alarms Connection (LEMO 1 – 5 pin)
Refer to Diagram: The RS-232 connector is a 5 pin female Lemo 1 connector. This
is used for connecting each alarm directly to an external source. An accessory 9 pin
female serial to Lemo 1 - 5 pin male cable will be required to use this feature, and is
not included in the standard kit.
Analog Output (LEMO 1 – 5 pin)
Refer to Diagram: One of the pins in the RS-232 connector is dedicated to high
speed analog out (0-10 volts). This can be terminated to a number of connectors,
BNC most common, and connected to a chart recording device to plot a curve as the
fastener is tightened.
Power Connector (LEMO 1 – 2 pin)
Refer to Diagram: The Lemo 1 2 pin connector is used for direct line power and
charging the Li-Ion battery pack.
39
Page 48
CHAPTER FIVE
THEORY OF OPERATION
5.1 Ultrasonic Measurement of Bolts
Note: The terms bolt, fastener, and threaded fastener are used interchangeably.
Ultrasonic measurement has proven to be the most reliable and cost effective
solution when:
Variations in friction or joint geometry prevent applied torque from controlling the
actual clamping force produced by the fastener with the required accuracy.
The clamping force must be monitored over the service life of the bolt.
Ultrasonic measurement of clamping load is obtained through a predictable decrease
in the sound velocity within the body of the bolt as the tensile load is increased. By
introducing a sonic pulse at one end of the bolt and accurately measuring the time
required for the echo to return from the opposite end, the ultrasonic length is
determined. As the fastener is tightened, the change in this ultrasonic length is used
to calculate and display the actual clamping force produced.
The physics governing this process are clearly understood, and have been employed
for many years in the fields of active sonar, or radar. Send a pulse of energy toward
an object (in this case the opposite or reflecting end of the fastener), and then
measure the time between the initial pulse and the returning echo.
While the concept is comparatively simple and ultrasonic measurement can produce
astoundingly accurate results, the selection of the optimum bolt and transducer, and
their coupling can be difficult. The MAX II minimizes these difficulties to the greatest
extent possible:
The variable width pulser system can send the maximum amount of energy to the
ultrasonic transducer, allowing the broadest possible range of transducers for a
given application.
The low noise and gain features of the receiver system allow signal detection and
measurement in the most difficult applications.
The digital signal processor optimizes the measurement process.
5.2 Features of the MAX II
The Dakota Ultrasonics MAX II, Ultrasonic Bolt Tension Monitor, defines the State of
the Art in the measurement of the actual clamp load produced by tightening a
fastener. The MAX II can measure time, elongation, load, stress, or %strain in bolts
of virtually any material from 1 inch to 100 feet in length. By storing the reference
waveform and displaying it for comparison while the elongation is being measured,
the MAX II minimizes operator training.
40
Page 49
MAX II Bolt Tension Monitor
5.3 Ultrasonic waves
Ultrasonic measurement requires the transmission of a suitable quantity of ultrasonic
energy through the length of the bolt. The relationship of the energy pulse frequency
to its penetration is important in energy transmission. Lower frequencies produce
longer wavelengths that will travel further through a given substance: while higher
frequencies produce shorter wavelengths. To use a familiar example: AM radio
signals are broadcast at relatively low frequencies and can be received hundreds of
miles away, over the horizon. Higher quality FM radio and television signals are
broadcast at much higher frequencies, and can only be received within a
comparatively short line-of-sight or distance.
The same phenomenon exists with ultrasound. A low frequency 1 MHz pulse travels
much farther through metal than a 5 MHz pulse. Therefore, a lower frequency
transducer is able to achieve an echo in a longer bolt, or in a bolt made of metal with
higher resistance to sound transmission (attenuation). While the lower frequency has
more penetration power, it also produces more unwanted noise. Low frequency
energy tends to spread, much like an unfocussed beam of light. When low frequency
energy is introduced at the end of a bolt, a significant portion is bounced from side to
side within the cylindrical shape, producing a noisy and distorted echo. Higher
frequency pulses tend to travel more directly down and back the centerline of a bolt,
with less noise and distortion.
5.4 Measurement Modes
In this section we will discuss the different measurements modes the MAX II is
capable of operating in, the transducers required, and the reasons for using specific
modes:
Pulse-Echo Mode (P-E)
Pulse-echo mode measures from the initial pulse (sometimes referred to as an
artificial zero) to the first echo (reflection). This is the standard most common
measurement mode typically used.
In this mode errors result from surface coatings applied to the bolt, as well as
temperature variations.
Since pulse-echo only requires one reflection (return-echo), it can be used for very
long bolts where achieving a second return-echo is difficult.
41
Page 50
Dakota Ultrasonics
Echo-Echo Mode (E-E)
Multi echo mode that measures from the first to the second return echo, and blocks
the initial pulse. This mode can slightly improve user transducer placement errors,
coated fasteners, and coated fasteners with changes in temperature. Because two
return echoes are required, generally not suitable for long fasteners applications.
Echo-Echo Verify Mode (E-EV)
Multi echo mode that measures from the first to the second return echo, and from the
second to the third return echo, then compares the measurements to “verify” they are
the same. Like the E-E mode, can slightly improve transducer placement errors,
coated fasteners, and coated fasteners with changes in temperature. Because three
return echoes are required, generally only used for shorter fastener applications.
42
Page 51
CHAPTER SIX
BOLT PREPARATION
The best balance between maximum frequency and noise suppression requires
selecting the best transducer for bolt measurement. The diameter of the transducer
(which is generally specified by the diameter of the actual piezoelectric crystal)
directly effects energy transmission: Larger diameter crystals have greater ability to
send and receive energy, and less of the energy tends to spread laterally. The MAX II Bolt Tension Monitor strives to achieve this ideal balance: direct transmission of the
strongest possible pulse, with the least amount of noise and distortion, down and
back the center of the bolt to obtain the most accurate measurement.
6.1 Use of Ultrasonic Couplant
Sonic energy at the frequency range used by the MAX II travels well through solid
materials and most liquids. It does not travel well through air. This variable resistance
to the passage of sonic energy is called sonic impedance. It is the sudden change in
impedance which occurs when the sound pulse attempts to cross the metal / air
boundary at the end of the bolt, which causes most of the energy to be returned as
an echo. To make a familiar comparison: light crossing the transparent glass
boundary of a mirror and reflecting back an image from the nontransparent silvered
back is much like an echo.
Any air gap between the face of the transducer and the end of the bolt will prevent
the sonic energy from crossing. The gap must be filled with a suitable coupling fluid.
Normally, a liquid ultrasonic couplant is applied between the transducer and the bolt.
Since liquid has sonic impedance closer to the transducer and bolt material than air,
it forms a continuous path for the outgoing pulse and the returning echo.
Many liquids can serve as an adequate couplant, however liquids with lower sonic
attenuation will produce better results. Liquids containing glycerin offer such low
impedance, and couplant manufactured for ultrasonic testing, such as the one
shipped with the MAX II, produce the best results.
The single purpose of the couplant is to fill the air gap between the transducer and
the bolt end. This is accomplished more easily with a liquid that is viscous enough to
stay in place. Very viscous substances can create such a thick layer between the
transducer and bolt that measurement errors occur. Also, viscous substances can
trap air bubbles, which prevent adequate energy transmission. Again, the ultrasonic
couplant provided with the MAX II works best. Apply only the smallest quantity of
couplant required to fill the air gap, and carefully seat the transducer so that any
trapped air or excess couplant is squeezed out of the interface.
6.2 Transducer Contact Requirements
The goal is to transmit as much sonic energy as possible from the transducer into the
bolt, and to send that energy, to the greatest extent possible, down and back the
center of the bolt, as shown in Figure 1.
43
Page 52
Dakota Ultrasonics
Figure 1 Sound path in a good bolt
Smooth, even surfaced bolt ends that seat the entire active surface of the transducer
with minimum gap are required for accurate signal transmission. Bolt ends may need
to be cleaned, ground, etc. to achieve the required surface.
Avoid:
Rough or irregular surface’s which pr event adequate contact with the transducer.
Irregular or rough surfaces can be filled with couplant, but energy transmission
will still be reduced and dispersed causing mode conversions to occur from
reflections off the side walls of the bolt, as shown at left of Figure 2.
Bolt ends not perpendicular to the axis of the bolt, as shown at right of Figure 2.
Energy will be transmitted toward the side wall and reflect along the bolt, yielding
poor signal quality and possible measurement errors. Avoid alignment errors
exceeding 2 degrees.
Figure 2 Rough and angled transducer contact
Rusted, dirty, or thick paint-covered bolt ends. These coatings prevent sonic
energy from traveling between the transducer and the bolt. Very thin coating or
plating is acceptable.
Bolt ends with recessed grademarks, as shown at left of Figure 3. Couplant can
be used to fill recessed grademarks. Small indentations cause some loss of signal
strength, but normal measurement is still possible. Large or numerous
indentations cause the signal to be too weak for a reliable measurement.
Bolt ends with raised grade marks, or indentations with a raised edge, which
cause the transducer to be seated at an angle to the axis of the bolt, thus
preventing adequate contact, as shown at right of Figure 3.
44
Page 53
MAX II Bolt Tension Monitor
Figure 3 Effect of lowered and raised grade marks
6.3 Bolt End Reflectors
Smooth, flat reflecting bolt ends that are perpendicular to the axis of the bolt are
required for accurate echo reception. Bolt ends may need to be cleaned, ground, etc.
to achieve the required surface.
Note: Misalignment exceeding 2 degrees can cause significant errors.
Avoid:
Rough reflecting bolt ends. As shown in Figure 4, if the reflecting end of the bolt is
rough or curved, most of the reflected energy will be dispersed and a weak or
distorted echo will be received.
Reflecting bolt ends not perpendicular to the axis of the bolt. Sonic energy will be
reflected toward the sidewall of the bolt, as shown in Figure 5.
Nonperpendicular reflecting bolt ends due to bending of the bolt as shown in
Figure 6.
Figure 4 Rough reflective surface
Figure 5 Non Parallel reflecting Surface
45
Page 54
Dakota Ultrasonics
Figure 6 Reflection in a bending bolt
46
Page 55
CHAPTER SEVEN
TRANSDUCER SELECTION
7.1 Selecting the Transducer
Transducer selection is a very import part of getting the best results from the MAX II.
The frequency and diameter of transducer should be carefully selected using the
following information:
Select the largest diameter transducer that will seat completely on the end of the
bolt. If there are multiple applications and diameters to consider, select a
diameter that will work for as many applications as possible, thus reducing the
overall number of transducers needed.
When selecting the proper frequency, the following items should be taken into
consideration:
Higher frequencies are typically a better choice when measuring smaller
diameter bolts as the sound is better focused resulting in less beam spread
and more directivity.
Lower frequencies are more forgiving of potential bending and attenuative
materials. This is primarily due to the longer wavelength avoiding smearing or
distortion of the waveform. Longer wavelengths require more of a phase shift
before distortion will occur. Lower frequencies offer an increased amount of
dispersion and a reduced amount of directivity. As this may seem to go
against what may typically be considered a good choice, in the case of
bending it’s actually the best choice overall.
47
Page 56
CHAPTER EIGHT
MEASURING SYSTEM ZERO (CALIBRATION)
8.1 Introduction
System zeroing is the method of calculating the time required for each MAX II and
transducer combination to detect the echo. When an echo travels back through the
bolt to the transducer face, there is an electronic delay before the MAX II detects the
echo. Because of differences in the electronic parts, or the transducer and cable, the
delay is slightly different for each combination of MAX II and transducer. The time
delay is called the delay factor or zero time offset.
The MAX II is designed for use with one or two calibration bars having a known
ultrasonic velocity and known length. Comparing their known physical length and
measured ultrasonic length determines the system delay factor, or zero time offset.
The system delay factor makes the Dakota Ultrasonics MAX II interchangeable with
all other calibrated MAX II systems.
Once the delay factor is determined, the MAX II software automatically subtracts it
from the apparent measurement of the time required for the sonic signal to travel
through the bolt. Thus, the actual time of signal travel is determined, and
compensation is made for the slight difference in each system. Since every zeroed MAX II makes the same time measurement, the systems give the same result and
are interchangeable.
System Zeroing is only required if:
More than one MAX II or transducer will be used while measuring a set of bolts. If
the same MAX II and transducer are used, the amount of the delay is constant. If
unloaded length measurements were made with one MAX II, and the load
measurements were made with another, the difference in the delay factor could
cause an error, though in most cases the error would be very small. If it is
uncertain that the same unit and transducer will always be used, it is strongly
recommended that System Zeroing be checked whenever the MAX II used.
The application requires that the bolts be monitored over periodic intervals
through their service life. In this case, the MAX II must be zeroed in order to
maintain reliable and accurate measurements. Once again, If a transducer,
cable, or unit is replaced, the delay factor will change, resulting in erroneous
measurements.
8.2 Calibration / Zero misnomer
In the past there have been instances where users were under the impression that
zeroing the unit was the same as calibrating the unit. If the ultrasonic unit could
successfully measure the calibration blocks, the unit was calibrated. However, this is
not the case. The linearity of the unit and material type of the bolts are not calibrated
following a zero procedure.
48
Page 57
MAX II Bolt Tension Monitor
The MAX II should be sent in for calibration by Dakota Ultrasonics, or other
authorized service representative, on a periodic basis to verify proper operation of
the instrument. Dakota Ultrasonics recommends one-year intervals.
Depending on the how critical the application is, bolts should be calibrated in a lab
against a known load prior to measuring. A temperature bath should also be used
to determine the necessary temperature factors required.
The following sections are typical methods of how to perform and calculate a probe
zero using the MAX II. The proper method should be determined by the level of
accuracy required and the specifications and conditions of the application itself.
8.3 Creating a Group to Document Zero (Calibration) data
The first step is to setup a group to document our probe zero data. By doing this, all
the values and settings will be saved to the cell location for easy recall at a later time.
This will allow the user to easily verify the zero value and make any necessary
changes to the MAX II, by adjusting the zero value or temperature depending on the
circumstances or conditions.
Note: This section applies to all the Zero/Calibration options (auto, using a stand
alone bolt, and 3” & 6” cal bars / glass block.
Creating a Zero/Cal Group Name
Note: Select a name that references this group to Cal Data.
1) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right, and the ESC key multiple times to tab left,
until the DATA menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel.
49
Page 58
Dakota Ultrasonics
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until NEW is highlighted.
3) Press the ENTER key to display the New Group Edit Box.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NAME is
highlighted.
5) Press the ENTER key to activate the Alpha Edit Box.
6) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left and
right button wheel to highlight the appropriate alpha characters.
7) Press the ENTER key to select a character and advance to the next field of
the Group Name.
8) Use the CLR key to backspace if necessary.
9) Repeat steps 6 - 8 until the Group Name is completed.
10) Press the OK key to save the Group Name and return to the Group List
Items menu, or ESC to cancel entering the Group Name.
Creating a Group Note
50
Page 59
MAX II Bolt Tension Monitor
Note: Be sure to include a note that describes and references the Zero/Cal
data, and or bolt.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NOTE is
highlighted.
2) Press the ENTER key to activate the Alpha Edit Box.
3) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left or
right button wheel to highlight the appropriate alpha characters.
4) Press the ENTER key to select a character and advance to the next field of
the Group Note.
5) Use the CLR key to backspace if necessary.
6) Repeat steps 3 through 5 until the Group Note is completed.
7) Press the OK key to save the Group Note and return to the Group List Items menu, or ESC to cancel entering the Group Note.
51
Page 60
Dakota Ultrasonics
Selecting the Number of Bolts in the Group
Note: A group can contain up to 250 bolts. In this case, the number of bolts in
the group can be thought of as the number of reference points on the calibration
standards. If a standalone bolt is used, the group will contain 1 bolt. If the 3” &
6” cal bars are being used, then the group should contain 2 bolts. If the triple
sided glass block is being used, then the group should contain 3 bolts.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NUM BOLTS
is highlighted.
2) Press the ENTER key to display the Digits Edit Box.
3) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
4) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
5) Repeat steps 3 & 4 until the NUM BOLTS value is correctly displayed.
6) Press the OK key to save the NUM BOLTS and return to the Group List Items menu, or ESC to cancel entering the NUM BOLTS.
7) Press the OK key to display the Digits Edit Box and re-enter the NUM BOLTS.
52
Page 61
MAX II Bolt Tension Monitor
8) Press the OK key to save the NUM BOLTS and return to the Group List
Items menu, or ESC to cancel entering the NUM BOLTS.
Selecting the Number of Readings Per Bolt
Note: A bolt can have up to 51 possible measurements and 1 initial length (L-
REF). There must be at least one reading per bolt. Since this group is being
created to store Zero/Cal Data and verify your probe zero periodically, or before
starting a new application, consider selecting all 51 measurements locations.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until NUM READS
is highlighted.
2) Press the ENTER key to display the Digits Edit Box.
3) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
4) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
5) Repeat steps 3 & 4 until the NUM READS value is correctly displayed.
6) Press the OK key to save the NUM READS and return to the Group List Items menu, or ESC to cancel entering the NUM READS.
53
Page 62
Dakota Ultrasonics
Note: If a number less than 1 or greater than 51 is entered, an error message
box “VALUE IS OUT OF RANGE” will be displayed.
7) Press the OK key to display the Digits Edit Box and re-enter the NUM READS.
8) Press the OK key to save the NUM READS and return to the Group List Items menu, or ESC to cancel entering the NUM READS.
If there’s not enough memory available to create the group, an error message
box “NOT ENOUGH MEMORY“ will be displayed. Press the OK or ESC key to
return to the Group List Items menu. It may be necessary to free some
memory in the MAX II at this time.
Selecting the Starting Bolt Number
Note: Depending on the application and layout of the project, the user won’t
always want the starting bolt to be 1. This feature allows the user to define
what the starting number will be.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until START BOLT NUM is highlighted.
54
Page 63
MAX II Bolt Tension Monitor
2) Press the ENTER key to display the Digits Edit Box.
3) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
4) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
5) Repeat steps 3 & 4 until the START BOLT NUM value is correctly
displayed.
6) Press the OK key to save the START BOLT NUM and return to the Group List Items menu, or ESC to cancel entering the START BOLT NUM.
7) Press the OK key to display the Digits Edit Box and re-enter the START BOLT NUM.
8) Press the OK key to save the START BOLT NUM and return to the Group
List Items menu, or ESC to cancel entering the START BOLT NUM.
Selecting the Auto Increment Direction
The Auto Increment feature gives the user the ability to specify which direction
to advance the cursor after storing a reading.
1) Use the UP and DOWN arrow keys to scroll through the new Group List Items until INCR. DIR is highlighted.
55
Page 64
Dakota Ultrasonics
2) Use the LEFT & RIGHT arrow keys to toggle the Increment direction NONE, NORTH, EAST, SOUTH, or WEST.
3) When the correct Increment direction is dis played, continue on to the next
section “Saving the Group”.
Saving the Group
Once all the parameters are set, the user has the option of saving or canceling
the new group.
1) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the new Group List Items until CREATE NEW GROUP? is highlighted.
2) Press the ENTER key to accept the group parameters, and activate the
confirmation screen.
3) Press the OK key to save the New Group, or the ESC key to cancel the New Group setup and return to the DATA menu.
4) Press the MEAS key to return to the measurement screen to begin
measuring reference lengths.
56
Page 65
MAX II Bolt Tension Monitor
8.4 Auto Zero/Calibration
The auto calibration feature uses a single calibration bar and two multiples (echoecho mode) of the calibration bar to perform an automatic Two-Point calibration. If a
3” calibration bar is used, it would measure at 3”, and then again on the second
multiple at 6”. This zero option will typically be the preferred option, as it’s the easiest
option to use and for the most part is automatic in terms of operation. However,
depending on signal quality and calibration standard used, may not always work. If
valid signals cannot be acquired during the auto set routine, the MAX II will report
“Can’t find stable echo”. Before eliminating this option altogether and using one of
the manual options listed below, try relocating the transducer to various positions on
the end of the calibration standard first. Since the calibration standards are
cylindrical, they can sometimes create substantial sidewall noise, based on the the
length, transducer size, and frequency. Moving the transducer to the edge of the
cylinder will often times eliminate the noise by shooting down the edge of the
standard and allowing the MAX II to acquire a reasonable signal.
Now that the bolt group CAL DATA has been created in the previous section, we’re
ready to get started with the automatic zero/calibration process. The first thing to
note is the procedures in this section demonstrate a Two-Point calibration, but a very
fast and efficient one, with minimal adjustments required from the operator.
Measuring Calibration Standard – For the First Time
1) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the CAL menu is highlighted and displaying the
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel.
57
Page 66
Dakota Ultrasonics
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until ZERO MODE is
highlighted.
3) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll the zero mode options until the AUTO option is
displayed.
Note: The auto option will perform a two-point calibration option allows the
user to use two separate points for the probe zero calibration.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until MEASURE ZERO is
highlighted.
5) Press the ENTER key to display the One Point Zero list box.
6) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point Zero list until PHY LENGTH is
highlighted.
Note:PHY LENGTH is the actual physical length of the calibration standard.
7) Press the ENTER key to display the Digits Edit Box.
8) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
58
Page 67
MAX II Bolt Tension Monitor
9) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
10) Repeat steps 8 & 9 until the PHY LENGTH value is correctly displayed.
11) Press the OK key to return to the One Point Zero list, or ESC to cancel
entering the PHY LENGTH.
12) Press the ENTER key to display the Digits Edit Box.
13) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
14) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
15) Repeat steps 13 & 14 until the TEMP COEF value is correctly displayed.
16) Press the OK key to return to the One Point Zero list, or ESC to cancel
entering the TEMP COEF.
Note: The TEMP COEF should be set to 55 (99 metric) for the 3 & 6” bars
supplied by Dakota Ultrasonics. If the glass block is used, it should be set
to 0. The reason for this is because glass has a very low temperature
coefficient.
59
Page 68
Dakota Ultrasonics
17) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point Zero list until ULTRASONIC is
highlighted.
Note: Ultrasonic will measure the ultrasonic length of the calibration standard.
18) Press the ENTER key to display the measurement screen.
19) Press the key to automatically adjust the settings and measure the
calibration standard.
20) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the hot menu items until ACCEPT CAL is highlighted.
21) Press the ENTER key to accept the calibration and return to the One Point Zero list, or ESC to cancel the calibration.
22) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point Zero list until CALC ZERO is
highlighted.
60
Page 69
MAX II Bolt Tension Monitor
23) Press the ENTER key to calculate, change, and display the new velocity
and zero values, or ESC to cancel the calibration.
Note: If ENTER was pressed to calculate the new values, pressing the ESC
key once will display the CAL menu to review the new ZERO value
calculated.
Note: In order for the MAX II to display the correct measurement value for
documentation purposes in the CAL DATA group created in the previous
section, the material velocity calculated during the calibration process and
temperature coefficient must be set to the same values as in the calibration
section. Additionally, the Stress Factor must be set to 1.000.
24) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until VELOCITY is
highlighted.
25) Press the ENTER key to display the Digits Edit Box.
26) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
27) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
28) Repeat steps 21 & 22 until the VELOCITY value is correctly displayed.
61
Page 70
Dakota Ultrasonics
29) Press the OK key to return to the MATL menu, or ESC to cancel entering
the VELOCITY.
30) Repeat steps 32 – 37 to enter the TEMP COEF.
31) Repeat steps 32 – 37 to enter the STRESS FACTOR to 1.000”.
32) Press the key to display the CAL DATA group.
33) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to scroll the target cell cursor to the desired storage location.
Note: The first column A must be used to store reference lengths.
34) Press the ENTER key to save the current reading in the highlighted cell
location.
35) Abort the Grid View Box by pressing the MEAS key at any time.
36) The zero calibration is complete and documented.
37) Finally, press the MEAS key to return to the measurement screen, set up a
new bolt group, and begin taking measurements.
8.5 Using a Standard Bolt
Using any fastener that provides a good ultrasonic echo with both ends ground and
polished can make a simple and effective calibration standard. The primary objective
is to verify a zero value prior to measuring to avoid measurement errors if the MAX II,
transducer, or cable is replaced. While this sounds like an economic way to go, the
user must keep in mind that certified calibration standards are usually inclusive of an
ultrasonic length, velocity, and temperature coefficient that is certified according to a
specific set of standards. The following procedures outline how to use a standard
bolt as follows:
Now that a group has been created to store our probe zero data, the material type of
the standard zero/cal bolt must be selected. This will load the appropriate values for
velocity and the temperature coefficient into memory.
62
Page 71
MAX II Bolt Tension Monitor
Selecting the Bolt Material Type
1) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right and the ESC key multiple times to tab left until
the MATL menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel to scroll the tabbed menus.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until TYPE is highlighted.
3) Press the ENTER key to display the list of material types.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the material list until the appropriate material
is highlighted.
5) Press the ENTER key to display the confirmation screen.
6) Press the OK key to select the material and return to the menu screen, or ESC to cancel the material selection.
63
Page 72
Dakota Ultrasonics
Now that a bolt group has been created, and material type selected to save and
document the probe zero data, this next section will go through the process of
obtaining the information needed to use the standard bolt for a probe zero calibration
bar.
Setting up a Bolt Standard – For the First Time
1) With the menu items already active, press the MENU key multiple times to
tab right and the ESC key multiple times to tab left until the CAL menu is
highlighted and displaying the submenu items. Alternatively, press the LEFT and RIGHT arrow keys multiple times using the left button wheel to
scroll the tabbed menus.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until ZERO MODE is
highlighted.
3) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll the zero mode options until the FIXED option is
displayed. Note: Each time the arrow keys are pressed a confirmation
screen will appear to warn the user that the zero mode is being changed.
Press the OK key to advance to the next mode option.
Note: The fixed option sets the delay factor to zero. In other words, disables
the zero feature altogether.
64
Page 73
MAX II Bolt Tension Monitor
4) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the MATL menu is highlighted and displaying the
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel to scroll the tabbed menus.
5) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until TYPE is highlighted.
6) Press the ENTER key to display the list of bolt types.
7) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the bolt material types until the appropriate
bolt type is highlighted.
8) Press the ENTER key to display the confirmation screen.
9) Press the OK key to select the bolt type and return to the menu screen, or
press ESC to cancel the bolt type selection.
10) The new bolt type selected will be displayed to the right of the sub menu
item. Write down the values for the Velocity and Temperature Coefficient
also displayed next to the sub menu items below. These values will be
needed in one of the following steps.
11) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the GEOM menu is highlighted and displaying the
65
Page 74
Dakota Ultrasonics
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel to scroll the tabbed menus.
12) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until QUANTITY is
highlighted.
13) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll the quantity options until the ELONG option is
displayed.
14) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the AUTO menu is highlighted and displaying the
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel to scroll the tabbed menus.
15) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until APROX LEN is
highlighted.
Note: This is the approximate physical length of the fastener or bolt. This tells
the MAX II where to turn on the receiver and look for an echo. The area
scanned will be +/- 5% from the approximate length.
16) Press the ENTER key to display the Digits Edit Box.
66
Page 75
MAX II Bolt Tension Monitor
17) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
18) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the digit locations.
19) Repeat steps 17 & 18 until the APPROX LEN value is correctly displayed.
20) Press the OK key to set the Approximate Length and return to the menu
screen, or ESC to cancel entering the Approximate Length.
21) Use the UP and DOWN arrow keys to scroll through the sub menu items
until AUTO SET is highlighted.
Note: Both the Approximate Length and Auto Set feature could have also been
set and activated using the Hot Menu Items and Keypad Auto Set button as
well. However, since we are already in the Tab Menu Items, it was just as easy
as returning to the Hot Menu Items screen.
22) Apply a drop of couplant to the bolt or transducer, and attach it to one end
of the bolt. Rotate the transducer clockwise and counter clockwise applying
a small amount of pressure to eliminate any excess couplant between the
transducer and bolt surface. Be sure to always place the transducer in the
same location. This will help to eliminate any potential measurement errors
cause by changing the sound path.
67
Page 76
Dakota Ultrasonics
23) Press the ENTER key and the Ultrasonic Length of the bolt will be
displayed and should be documented and scribed on the bolt, along with the
Velocity and Temperature Coefficient, for future zero verification.
24) Proceed to the next section to save this length in the zero group CAL
DATA created in a previous section. DO NOT REMOVE THE
TRANSDUCER FROM THE BOLT.
Now that we’ve gathered all the data for the probe zero bolt, we need to document it
as outlined in the next section.
Storing the Reference Length
1) Press the MEAS key once to activate measure menu items. Press the
MEAS key multiple times to move down and the ESC key multiple times to
move up until the LOG cell is highlighted. Alternatively, press the UP
and DOWN arrow keys multiple times using the left button wheel.
Note: Pressing the key will immediately open the data group.
2) Press the ENTER key to display the Group View Box.
68
Page 77
MAX II Bolt Tension Monitor
3) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to scroll the target cell cursor to the desired storage location.
Note: The first column A must be used to store reference lengths.
4) Press the ENTER key to save the current reading in the highlighted cell
location.
5) Abort the Grid View Box by pressing the MEAS key at any time.
6) Proceed to the next section to perform and store the first Probe Zero
verification. DO NOT REMOVE THE TRANSDUCER FROM THE BOLT.
The next two sections outline the procedures of how to perform a probe zero
calibration by calculating a zero value, or alternatively adjusting the temperature
value to match the existing probe zero value. When should I use the Calc Zero
feature versus adjusting the Temperature, and why?
The only time the Calc Zero feature should be used is when a different MAX II,
transducer, or transducer cable is being used, other than the one initially used to
obtain the probe zero data for the probe zero calibration bolt. In this case, calculating
the probe zero value forces the new hardware to match with the original. If the
hardware has not changed, the user should not use this feature. If the hardware
hasn’t changed only the temperature value should be adjusted to match the existing
zero values.
The next two sections outline first, the procedure for calculating a probe zero
because the hardware has changed, and second, by adjusting the temperature value
because the hardware is the same and the values do not match.
Performing a Probe Zero Calibration
Note: User has selected this section because the MAX II, transducer, or
transducer cable has changed.
69
Page 78
Dakota Ultrasonics
1) Press the MENU key once to activate the menu items tab. Press the
MENU key multiple times to tab right, and the ESC key multiple times to tab
left, until the CAL menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel to scroll the tabbed menus.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until ZERO OPTION is
highlighted.
3) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll the zero mode options until ONE POINT is displayed.
Note: Each time the arrow keys are pressed a confirmation screen will
appear to warn the user that the zero mode is being changed. Press the OK
key to advance to the next mode option.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until MEASURE ZERO is
highlighted.
70
Page 79
MAX II Bolt Tension Monitor
5) Press the ENTER key to display the One Point Zero Edit Box.
6) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point List Items until PHY LEN 1 is
highlighted.
7) Press the ENTER key to display the Digits Edit Box.
Note: Enter the known ultrasonic length of the bolt that was documented and
stored in the previous section. We will consider this ultrasonic length to be the
actual physical length from this point forward. Reminder: It was stored in the
first column of the probe zero group.
8) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
9) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
10) Repeat steps 8 & 9 until the PHY LEN 1 value is correctly displayed.
71
Page 80
Dakota Ultrasonics
11) Press the OK key to return to the One Point Zero List, or ESC to cancel
entering the PHY LEN 1 value.
12) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point Zero List Items until
VELOCITY is highlighted.
13) Press the ENTER key to display the Digits Edit Box.
Note: Enter the velocity value of the bolt that was documented in the previous
section. Reminder: The value was written down and scribed on the side of the
bolt, and is the velocity used for the probe zero bolt.
14) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
15) Press the LEFT and RIGHT arrow keys multiple times using the left
right button wheel to scroll the digit locations.
16) Repeat steps 14 & 15 until the VELOCITY value is correctly displayed.
17) Press the OK key to return to the One Point Zero List, or ESC to cancel
entering the VELOCITY value.
18) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point Zero List Items until TEMP COEF is highlighted.
72
Page 81
MAX II Bolt Tension Monitor
19) Press the ENTER key to display the Digits Edit Box. Note: Enter the temperature coefficient value of the bolt that was documented
in the previous section. Reminder: The value was written down and scribed on
the side of the bolt. It is the temperature coefficient used for the probe zero
bolt.
20) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
21) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
22) Repeat steps 20 & 21 until the TEMP COEF value is correctly displayed.
23) Press the OK key to return to the One Point Zero List, or ESC to cancel
entering the TEMP COEF value.
24) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point Zero List Items until
ULTRASONIC 1 is highlighted.
73
Page 82
Dakota Ultrasonics
25) Press the ENTER key to display the measurement screen.
26) Press the key to automatically adjust the settings and measure the
calibration standard.
27) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the hot menu items until ACCEPT CAL is highlighted.
28) Press the ENTER key to accept the calibration and return to the One Point Zero list, or ESC to cancel the calibration.
29) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the One Point Zero list until CALC ZERO is
highlighted.
30) Press the ENTER key to calculate, change, and display the new velocity
and zero values, or ESC to cancel the calibration.
Note: If ENTER was pressed to calculate the new values, pressing the ESC
key once will display the CAL menu items to review the new ZERO value
calculated.
31) Finally, press the MEAS key to return to the measurement screen and
begin taking readings.
Typically when the zero value is off and the hardware has not changed, it’s because
the temperature of the bolt has changed. In this case, the zero value should not be
changed, but the temperature value should be. Therefore the bolt becomes sort of a
temperature sensor in itself. This is also a good way to monitor temperature changes
in the bolt. The procedures below demonstrate how to adjust the temperature to
match the zero value.
Adjusting the Temperature to Match the Zero Value
74
Page 83
MAX II Bolt Tension Monitor
This section assumes that a temperature sensor has not been connected
and the temperature mode is set to “manual”. If the temperature sensor
was connected and activated, the length of the bolt should match within
tolerance.
Note: User has selected this section because the MAX II, transducer, or
transducer cable has not changed and the elongation is outside the tolerance of
+/- .0005”.
Note: This section assumes that a group CAL DATA has been created and
opened/active, as outlined in section 8.3.
1) Press the MEAS key once to activate measure menu items. Press the MEAS key multiple times to move down and the ESC key multiple times to
move up until the LOG cell is highlighted. Alternatively, press the UP
and DOWN arrow keys multiple times using the left button wheel.
Note: Pressing the key will immediately display the CAL DATA group.
2) Press the ENTER key to display the Group View Box.
3) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to scroll the stored readings and corresponding display view. Notice
75
Page 84
Dakota Ultrasonics
as the cursor is moved to a different cell, the display will be updated with the
display view saved with the reading.
4) Scroll the cursor to the next blan k cell for the probe zero bolt. This will
always be a cell located in columns B – ZZ. As soon as the user has
scrolled to blank cell, the MAX II will switch into elongation mode and use all
the data from the probe zero bolt initially stored.
5) Press the MEAS key once to activate Hot Menu items. Press the MEAS
key multiple times to move down and the ESC key multiple times to move up
until the TEMP cell is highlighted. Alternatively, press the LEFT and
RIGHT arrow keys multiple times using the left button wheel.
6) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll the TEMP value.
7) Continue to scroll the temp value until the elongation reads 0.0000. When
the value is at 0.0000 the MAX II is officially zeroed and ready to store or
document the zero data prior to making measurements.
8) Press the ENTER key to store the 0.0000 elongation value. Why bother
storing the 0.0000 elongation value? Because the adjustment to
temperature is also stored with the measurement. This documents the
changes for reporting requirements.
76
Page 85
MAX II Bolt Tension Monitor
9) Finally, press the MEAS key to return to the measurement screen, set up a
new bolt group, and begin taking readings.
8.6 Calibration / Zero Bars & Triple Sided Glass Block
Historically a set of 3” & 6” mild steel calibration bars, or a triple sided glass block
have been used for performing a probe zero. The bars/block are generally measured
and certified to a specific set of standards in a professional calibration lab, and the
corresponding length, velocity, and temperature coefficient are documented. Dakota
Ultrasonics carries a custom set of cal bars and an optical glass block that are
measured and calibrated according to national standards. The primary advantage of
using these bars/block versus setting a standard bolt aside, as explained in the
previous section, is the possibility of losing the stand alone bolt. Because the factory
3” & 6” bars and glass block are calibrated with documentation, these can be
interchanged between units and cal bars/blocks.
While the 3” & 6” bars provide two specific points to demonstrate linearity, the triple
sided glass block has a third reference point. The glass block has a 1”, 2”, & 3”
reference. Generally the user will set up the two-point calibration on the 1” & 3” sides
first, and use the 2” side for additional verification purposes. This section explains
the procedure for using the factory calibration bars and glass block as a means of
probe zeroing the MAX II.
The first step is to setup a group to document our probe zero data, as previously
outlined in section 8.3. By doing this, all the values and settings will be saved to the
cell location for easy recall at a later time. This will allow the user to easily verify the
zero value and make any necessary changes to the MAX II, by adjusting the zero
value or temperature depending on the circumstances or conditions.
Now that the bolt group has been created to document the probe zero data, we’re
ready to get started with the probe zero process. The first thing to note is, the
procedures in the next section demonstrate a Two-Point calibration. However, the
same procedures apply to the One-Point calibration option also. The user would
simply follow the same procedures and ignore references to the second point.
Measuring Calibration Standards – For the First Time
77
Page 86
Dakota Ultrasonics
Note: It is assumed that the temperature sensor is connected to the MAX II,
and semi automatic or automatic mode has been selected. The
temperature sensor should also be attached to the specific calibration bar
being measured. If an external pyrometer or other method will be used, the
temperature mode should be set to manual, and the temperature manually
entered into the gauge.
1) With the menu items still active from the previous section, press the MENU
key multiple times to tab right and the ESC key multiple times to tab left until
the CAL menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until ZERO MODE is
highlighted.
3) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll the zero mode options until the TWO POINT option is
displayed. Each time the arrow keys are press, and confirmation screen will
appear letting the user know that the ZERO MODE is being changed.
Pressing the OK key each time will allow the mode to be changed.
Note: The two-point option allows the user to use two separate points for the
probe zero calibration.
78
Page 87
MAX II Bolt Tension Monitor
Note: The one point option can optionally be selected if only one cal bar will be
used. Although the procedures below are described with the two-point option in
mind, they will also work in the case of a one-point calibration.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until MEASURE ZERO is
highlighted.
5) Press the ENTER key to display the Two Point Zero list box.
6) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the Two Point Zero list until PHY LEN 1 is
highlighted.
Note:PHY LEN 1 is the actual physical length of the first calibration standard
noted on the certificate included with the bars. If the glass block is being used,
the 1” side should be used for PHY LEN 1.
7) Press the ENTER key to display the Digits Edit Box.
8) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
9) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
10) Repeat steps 8 & 9 until the PHY LEN 1 value is correctly displayed.
79
Page 88
Dakota Ultrasonics
11) Press the OK key to return to the Two Point Zero list, or ESC to cancel
entering the PHY LEN 1.
12) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the Two Point Zero list until PHY LEN 2 is
highlighted.
Note:PHY LEN 2 is the actual physical length of the second calibration
standard. If the glass block is being used, the 3” side should be used for PHY LEN 2.
13) Press the ENTER key to display the Digits Edit Box.
14) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
15) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
16) Repeat steps 14 & 15 until the PHY LEN 2 value is correctly displayed.
17) Press the OK key to return to the Two Point Zero list, or ESC to cancel
entering the PHY LEN 2.
18) Press the UP and DOWN arrow keys to scroll through the Two Point Zero
list until VELOCITY is highlighted.
Note: This refers the velocity of the probe zero cal bars. Since there is a
velocity for each cal bar, use the velocity of the longest cal bar as it will be most
significant – 6” bar. If the glass block is being used, it will have only one
velocity specified for the block.
19) Press the ENTER key to display the Digits Edit Box.
80
Page 89
MAX II Bolt Tension Monitor
20) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
21) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
22) Repeat steps 20 & 21 until the VELOCITY value is correctly displayed.
23) Press the OK key to return to the Two Point Zero list, or ESC to cancel
entering the VELOCITY.
24) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the Two Point Zero list until TEMP COEF is
highlighted.
Note: This should be set to 55 (99 metric) for the 3 & 6” bars supplied by
Dakota Ultrasonics. If the glass block is used, it should be set to 0. The reason
for this is because glass has a very low temperature coefficient.
25) Press the ENTER key to display the Digits Edit Box.
26) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
27) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
28) Repeat steps 26 & 27 until the TEMP COEF value is correctly displayed.
29) Press the OK key to return to the Two Point Zero list, or ESC to cancel
entering the TEMP COEF.
30) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the Two Point Zero list until POLARITY is
highlighted.
81
Page 90
Dakota Ultrasonics
Note: The default is AUTO, allowing the MAX II the ability to select either
positive or negative polarity. However, the polarity can be set and fixed to a
specific polarity, positive/negative, as selected by the user.
31) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll AUTO, POSITIVE or NEGATIVE polarity options.
32) Press the ESC key once to leave the Two Point Zero list.
33) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the MATL menu is highlighted and displaying the
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel.
Note: In order for the MAX II to display the correct measurement value during
calibration, the material velocity and temperature coefficient must be set to the
same values as in the calibration section, and the stress factor set to 1.000.
34) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until VELOCITY is
highlighted.
35) Press the ENTER key to display the Digits Edit Box.
36) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
82
Page 91
MAX II Bolt Tension Monitor
37) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
38) Repeat steps 34 & 35 until the VELOCITY value is correctly displayed.
39) Press the OK key to return to the MATL menu, or ESC to cancel entering
the VELOCITY.
40) Repeat steps 34 – 37 to enter the TEMP COEF.
41) Repeat steps 34 – 37 to enter the STRESS FACTOR as 1.000”.
42) Proceed to the next section.
Before the probe zero is calculated the cal bars / glass block needs to be
ultrasonically measured. Once the zero value has been calculated, the results will
then need to be documented. This procedure is demonstrated in the next section.
Setting up the MAX II for Measurement
Note: Check to see if the system was previously calibrated. You should NOT
change the calibration unless the transducer, transducer cable, or instrument
has been changed. In any event, the probe zero calibration should always be
checked prior to changing it and only changed if it’s required. If the MAX II has
been previously calibrated, open the calibration data saved in the MAX II and
check the probe zero by simply measuring the bars in an empty location
(columns B – ZZ) in the existing probe zero data group. If the zero is off by a
value greater than .0005”, repeat the two point calibration section and
overwrite/record the values in column A of the calibration group for both the 3”
& 6” bars.
1) With the menu items still active from the previous section, press the MENU
key multiple times to tab right and the ESC key multiple times to tab left until
83
Page 92
Dakota Ultrasonics
the GEOM menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until QUANTITY is
highlighted.
3) Press the LEFT and RIGHT arrow keys multiple times using the left
button wheel to scroll the quantity options until the ELONG option is
displayed.
Note: This will set the quantity display in terms of elongation.
Note: In order to record the data for both the 3” & 6” (1” & 3” glass block), the
CAL DATA group created in an earlier section must be opened.
4) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the DATA menu is highlighted and displaying the
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel.
84
Page 93
MAX II Bolt Tension Monitor
5) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until OPEN is highlighted.
6) Press the ENTER key to display the list of log files.
7) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the log names until CAL DATA is highlighted.
8) Press the ENTER key to open the log, followed by pressing the OK to
confirm “load from memory”, or ESC to cancel opening the log file.
9) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the CAL menu is highlighted and displaying the sub
menu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel.
10) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until MEASURE ZERO is
highlighted.
11) Press the ENTER key to display the Two Point Zero list.
12) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until ULTRASONIC 1 is
highlighted.
13) Apply a drop of couplant to the standard or transducer and attach it to one
end of the 3” calibration bar.
14) Press the ENTER key to display the measurement screen.
Note: Rotate the transducer clockwise and counter clockwise applying a small
amount of pressure to eliminate any excess couplant between the
transducer and cal bar surface.
85
Page 94
Dakota Ultrasonics
15) Press the key to automatically setup and measure the 3” cal bar.
Note: Once an echo is found and the MAX II is measuring the cal bar, the
GAIN, as well as the POLARITY may need to be adjusted. Using a large
diameter transducer can produce an extremely strong signal and often the
gain can be turned down to allow the user to see the peaks of the
waveform. A thorough understanding of the section on “Interpreting the Waveform” is very important prior to making any adjustments.
16) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the hot menu items until ACCEPT CAL is highlighted.
17) Press the ENTER key to accept the calibration and return to the Two Point Zero list, or ESC to cancel the calibration.
18) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the Two Point List items until ULTRASONIC 2
is highlighted.
19) Apply a drop of couplant to the bolt or transducer and attach it to one end of
the 6” calibration bar. Use the 3” for the glass block.
20) Press the ENTER key to display the measurement screen.
Note: Rotate the transducer clockwise and counter clockwise applying a small
amount of pressure to eliminate any excess couplant between the
transducer and cal bar surface.
86
Page 95
MAX II Bolt Tension Monitor
21) Press the key to automatically setup and measure the 6” cal bar.
Note: Once an echo is found and the MAX II is measuring the cal bar, the
GAIN, as well as the POLARITY may need to be adjusted.
22) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll the hot menu items until ACCEPT CAL is highlighted.
23) Press the ENTER key to accept the calibration and return to the Two Point Zero list, or ESC to cancel the calibration.
24) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the Two Point Zero list until CALC ZERO is
highlighted.
25) Press the ENTER key to calculate the zero and velocity values.
26) Make note of the velocity value calculated, as it will need to be changed in
the MATL menu prior to saving the measurements in the CAL DATA group.
27) Press the ESC key to review the ZERO value calculated.
28) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the MATL menu is highlighted and displaying the
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel.
29) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until VELOCITY is
highlighted.
30) Press the ENTER key to display the Digits Edit Box.
31) Press the UP and DOWN arrow keys multiple times using the left or
right button wheel to scroll the highlighted value.
87
Page 96
Dakota Ultrasonics
32) Press the LEFT and RIGHT arrow keys multiple times using the left or
right button wheel to scroll the digit locations.
33) Repeat steps 31 & 32 until the VELOCITY value is correctly displayed.
34) Press the key to display the CAL DATA group.
Note: Since the last data point taken was ULTRASONIC 2, or the 6” cal bar,
press the UP, Down, Left, Right arrow keys multiple times using the
left button wheel to highlight A2 for the first reading of the 6” cal bar.
35) Press the ENTER key to store the measurement in location A2.
36) Press the MENU key multiple times to tab right and the ESC key multiple
times to tab left until the CAL menu is highlighted and displaying the
submenu items. Alternatively, press the LEFT and RIGHT arrow keys
multiple times using the left button wheel.
37) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until MEASURE ZERO is
highlighted.
38) Press the ENTER key to display the Two Point Zero list.
39) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until ULTRASONIC 1 is
highlighted.
88
Page 97
MAX II Bolt Tension Monitor
40) Apply a drop of couplant to the cal bar or transducer and attach it to one
end of the 3” calibration bar. Make sure it is in the original position when
the measurement was first taken.
41) Press the ENTER key to display the measurement screen.
42) Press the key to automatically setup and measure the 3” cal bar.
Note: Rotate the transducer clockwise and counter clockwise applying a small
amount of pressure to eliminate any excess couplant between the
transducer and cal bar surface. Continue to rotate until the actual length of
the cal standard is being displayed. This ensures the transducer is back to the original position when the zero measurement was first taken.
40) Press the key to display the CAL DATA group.
41) Press the UP, Down, Left, Right arrow keys multiple times using the
left button wheel to highlight A1 for the first reading of the 3” cal bar.
42) Press the ENTER key to store the measurement in location A1.
Note: The MAX II is now properly zeroed and ready for action.
This next section demonstrates how to go back and verify if the probe zero value is
still linear and “In Spec” at a later time. It’s important to note that user should never
have to change or re-calculate the probe zero value again, unless the MAX II,
transducer, or cable has been replaced. If the transducer or cable has changed, and
the probe zero value re-calculated, the change in the zero value should be very
small. Therefore, if the zero is re-calculated and the delta is very large, something
else has gone wrong and the user should become suspicious of the how well the
zero/cal was performed.
If we consider the initial probe zero value constant, as the hardware cal bars or glass
block have not been replaced, the future verifications should always show an
elongation value of +/- 0.0005”, in order to be considered “In Spec”. If the probe
zero/cal is out of spec, the user should redo the zero/cal procedure in its entirety.
The next section outlines the verification procedures.
89
Page 98
Dakota Ultrasonics
Verifying the Probe Zero at a Later Time
1) Press the MENU key once to activate the menu items tab. Press the MENU
key multiple times to tab right, and the ESC key multiple times to tab left,
until the DATA menu is highlighted and displaying the submenu items.
Alternatively, press the LEFT and RIGHT arrow keys multiple times
using the left button wheel.
2) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the sub menu items until OPEN is highlighted.
3) Press the ENTER key to display the Open Group List Box.
4) Press the UP and DOWN arrow keys multiple times using the left
button wheel to scroll through the list menu items until the group name containing the probe zero dataCAL DATA is highlighted.
5) Press the ENTER key to load the zero data group into memory, followed by
pressing the OK key to confirm loading the group into memory.
Note: The user will always use this group for the zero verification procedure,
as it contains the original settings and measurement data of the probe zero
calibration standards. Multiple data groups may have been created for different
transducer types and frequencies.
6) Apply a drop of couplant to the cal standard or transducer, and attach it to
one end of the cal standard. Rotate the transducer clockwise and counter
90
Page 99
MAX II Bolt Tension Monitor
clockwise applying a small amount of pressure to eliminate any excess
couplant between the transducer and cal standard. Be sure to always place
the transducer in the same location. This will help to eliminate any potential
measurement errors caused by changing the sound path.
7) Press the MEAS key once to activate the measure menu items. Press the
MEAS key multiple times to move down and the ESC key multiple times to
move up, until the LOC cell is highlighted. Alternatively, Press the UP
and DOWN arrow keys multiple times using the left button wheel.
Note: Pressing the key will immediately open the data file.
8) Press the ENTER key to display the Group View Box.
9) Press the UP, DOWN, LEFT, & RIGHT arrow keys using the left button
wheel to scroll the target cell cursor to the desired storage location.
Note: Since this is the 1st verification following the initial measurement of the
Probe Zero Cal Bars, the cursor should be located on a cal standard in
column B. It’s also important to note that the L-REF stored in column A, also contains all the MAX II settings when the L-REF was initially measured. These
settings will automatically be copied to all the columns B-ZZ, for each
individual bolt. Therefore, no adjustments to the MAX II should be
necessary.
10) If the elongation is +/- .0005” and “In Spec”, Press the ENTER key to save
the current reading in the highlighted cell location, storing all the current
probe zero verification data. Repeat steps 6 - 10 for the other probe zero
91
Page 100
Dakota Ultrasonics
calibration standards. If the probe zero is “Out of Spec” perform the
zero procedure in its entirety.
92
Loading...
+ hidden pages
You need points to download manuals.
1 point = 1 manual.
You can buy points or you can get point for every manual you upload.