DAKOTA ULTRASONICS MAX II User manual

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CHAPTER ONE
MEASURING SYSTEM ZERO (CALIBRATION)
1.1 Introduction
In this chapter will be focused on establishing a system zero to enable the group data to
be portable between different hardware devices with limited measuring error. Data
created using one MAX II, can send the data file to another operator for use in another
MAX II, transducer (diameter or frequency), or cable (length or type). The MAX II offers
a few selectable calibration options for flexibility based on preference, or the type of
calibration standard used. Every Max II, transducer, and cable will have a slightly
different system delay because of differences in electronic components and materials.
However small, even identical transducers by diameter and frequency may result in
different delay times. When porting existing data to another hardware set, it’s always
optimal to use the same transducer diameter, frequency, and cable length to minimize
potential measurement error. These items should be documented for reference in the
data group.
The sections that follow will outline the procedures for all the System Zero options:
Fixed, Auto, One Point, and Two Point. A system zero is only required if the bolts will
be monitored/measured over the service life of the bolt…measured more than one time
(later date/time). An example might be measuring bolts in a refinery that requires a
shutdown and re-measurement once a year and every year thereafter for the service life
of the bolts. An example when a zero is not necessary is when measuring auto engine
bolts on an assembly line. In the first example one of the calibration options (auto, one
point, two point) would be used, while in the second example the calibration option
should be set to ‘fixed’.
A system zero should be done or checked any time the hardware configuration changes
in any way. If the MAX II monitor, transducer, or cable has changed, the zero should be
checked against the current zero calibration group in the project folder
CAL_ZERO_DATA. If the elongation is not reasonably close to “0”, then the zero
process should be repeated. Regardless, the operator should always take the time to
verify the system zero prior to starting a job, even when using the same hardware
configuration for existing data.
1.2 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 bars or glass block, the unit could be considered
calibrated. However, this is not the case. The linearity of the unit and material type of
the bolts are not calibrated following a system zero procedure.

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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.
Check in with your quality department to verify their duration requirement for “Test &
Measurement Equipment”.
1.3 Creating a Group to Document Zero (Calibration) Data
A project folder named “CAL_ZERO_DATA” will automatically be created following the
completion of a “One Point”, “Two Point”, or “Auto” calibration option…if one doesn’t
already exist. A group/log will automatically be created inside of the ‘project folder’ with
a ‘date/time’ stamp, each and every time the zero process has been successfully
completed. By default, the group/log will consist of 5 bolts and 10 measurements per
bolt, allowing for additional calibration points, verification, and recordation. The group
log will contain the zero measurements, as well as the diameter and calculated
frequency of the transducer used.
The group/log files created will remain on the SD memory card until manually deleted,
and provide the user with additional documentation regarding when the zero process
was performed, as well as the outcome of the zero calibration process.
File Name (format): CALZERO211202_132519
Date(yr/month/day)_Time(hr/min/sec)
Note: This section applies to all the Zero/Calibration options (one point, two point,
auto).
Note: Refer to chapter Error! Reference source not found. for instructions on how to
Create, Open, Edit (group name, note), Delete (a group/log), or Close (group) in a
project folder.
Overview

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1.4 Auto - Zero/Calibration
The auto calibration feature uses a single steel calibration bar and two measurements,
the second at twice the length (i.e. 3” bar at 3” & 6”). This zero option will typically be
most preferred, as it’s fully automated and simple to use. However, depending on
signal quality and the material type of calibration standard, it may not always work (not
recommended for use with our triple path glass block). 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 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 stable
echo.

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We’re ready to get started with the automatic zero/calibration process. The first thing to
note is the procedures in this section demonstrate an automatic ‘two-point’ calibration
using a 3” Cal Bar that’s fast and efficient, requiring minimal adjustments from the
operator.
Note: The temperature sensor should be connected to the gauge with the Temp Mode
set to ‘auto’, located in the utility menu, then placed on the serial # flat of the Cal Bar.
This will compensate for temperature shifts and avoid measurement errors.
Caution:
A very small amount of “WATER”, or other non-intrusive fluid with a similar viscosity,
should be used as the couplant between the transducer and calibration standard
selected. This will avoid creating a couplant film layer between them and cause an “out
of tolerance” condition > +/- 0.001” for the 3” cal bar.
Auto System Zero
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.
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.

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Note: The auto option will perform a two-point calibration using a single 3” cal bar
(pt# X-000-0011) and measurements of 1x & 2x lengths.
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 Digits Edit Box and adjust the physical
length of the cal bar.
6) Press the UP, DOWN, LEFT, & RIGHT arrow keys multiple times using
the left or right button wheel to scroll the highlighted value until the desired
PHY LENGTH is correctly displayed.
Note: PHY LENGTH is the actual physical length of the calibration standard
noted on the calibration certificate.
7) Press the OK key to save the PHY LENGTH and display the PROBE
DIAMETER List Box.

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8) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll the probe diameter options.
9) Press the ENTER key to select the probe diameter and start the automated
zero process.
Note: The Max II will automatically begin the wave analysis for each
measurement, display a summary page of the fit, calculated velocity, zero
values, and return to the main measurement screen when completed.
Caution: Do not disrupt the zero process until completed
Note: Refer to chapter Error! Reference source not found. for
instructions on how to Create (group), Open, Edit (file name, note), Delete (a
group/log), Close (group) in a project folder.
1.5 One & Two Point Zero Calibration
This section will outline the procedure to perform a one or two point system zero
calibration. The process using either method are virtually identical, with the exception of
entering the additional physical length of the second bar, averaging the two velocities
noted on the calibration certificates, and entering the average velocity into the MAX II.
To reiterate, a data group will automatically be created following the completion of either
of these two zero calibration methods. For additional information on the group data file
refer to section 1.3.
Calibration Standards:
1. 3” Steel (type 4140 pt# X-000-0011) – Used for one or two point zero calibration
options, using the first, and or the second (i.e. 3” & 6”) multiple echo.

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2. 3” & 6” Steel (type 4140 pt# X-000-0010) – Used for one or two point zero
calibration options in a number of configurations (individual or paired).
3. Triple Path Glass Block (1”, 2”, 3” pt# X-000-0020) – Most commonly used for all
three points. Two point using 1” & 3”, followed by a linear verification point
measured and recorded at 2” after completion of the Two Point procedure.
Note: The temperature sensor should be connected to the gauge with the Temp Mode
set to ‘auto’, located in the utility menu, then placed on the serial # flat of the Cal Bar.
This will compensate for temperature shifts and avoid measurement errors. If the triple
path glass block will be used as the cal standard, the temp sensor is not necessary with
the temperature coefficient of glass close to 0.
Caution:
A very small amount of “WATER”, or other non-intrusive fluid with a similar viscosity,
should be used as the couplant between the transducer and calibration standard
selected. This will avoid creating a couplant film layer between them and cause an “out
of tolerance” condition > +/- 0.001” for the 3” & 6” cal bars, or +/- 0.0005” for the triple
path glass block.
Triple Path Glass Block -
If the operator will be using the glass block for the zero calibration process, there are
only a few changes necessary:
 Physical lengths (PHY LEN) will be performed at 1” & 3”.
 Temperature coefficient (TEMP COEF) will be set to “0”.
 Recordation of the 2” side in the data group file.
The physical measurements documented on the glass block calibration certificates were
dimensionally measured in the center on all three sides (1”, 2”, & 3”). The transducer
should be placed in the same location during the calibration process.
The zero calibration procedure is as follows:
One & Two Point System Zero

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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 sub menu 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 either the ONE POINT or
TWO POINT option is displayed.
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.

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5) Press the ENTER key to display the Zero Calibration menu items.
6) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the sub menu items until PHY LEN 1 is highlighted.
7) Press the ENTER key to display the Digits Edit Box and adjust the physical
length of the cal bar.
8) Press the UP, DOWN, LEFT, & RIGHT arrow keys multiple times using
the left or right button wheel to scroll the highlighted value until the desired
PHY LEN 1 is correctly displayed.
Note: PHY LEN 1 is the actual physical length of the calibration standard noted
on the calibration certificate.
9) Press the OK key to save PHY LEN 1 and display the Zero Calibration menu
items.
10) Repeat steps 6 – 9, if using the TWO POINT zero calibration method, to enter
and save PHY LEN 2.

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11) 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.
12) Press the ENTER key to display the Digits Edit Box and adjust the
VELOCITY of the cal bar.
Note: If using the TWO POINT method, the average velocity of the cal bars
should be entered (Cal Bar Vel1 + Cal Bar Vel2) / 2.
13) Press the OK key to save VELOCITY and display the Zero Calibration menu
items.

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14) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the sub menu items until TEMP COEF is highlighted.
15) Press the ENTER key to display the Digits Edit Box and adjust the TEMP
COEF.
Note: The Temperature Coefficient (Temp Coef) should be set to ’55’ when using
the 3” (pt# X-000-0011) or 3” & 6” (pt# X-000-0010) steel cal bars, and ‘0’
when using the triple path glass block (pt# X-000-0008).
16) Press the UP, DOWN, LEFT, & RIGHT arrow keys multiple times using
the left or right button wheel to scroll the highlighted value until the desired
TEMP COEF is correctly displayed.
17) Press the OK key to save the TEMP COEF and display the Zero Calibration
menu items.
18) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the sub menu items until POLARITY is highlighted.

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19) Press the LEFT and RIGHT arrow keys multiple times using the right
button wheel to scroll the POLARITY options (auto, positive, negative) until the
desired option is displayed.
Note: AUTO is the default option and will analyze both sides of the waveform
(positive/negative) and attempt to determine the optimal polarity. Experienced
operators can opt to override this option by directly setting the polarity to either
POSITIVE or NEGATIVE as is needed.
20) Clean both the cal bar and transducer surface and apply a small drop of
couplant to the surface of the cal bar. Attached the transducer and rotate it
clockwise and counter clockwise to force out the excess couplant. Center the
transducer. Be methodical with this process to eliminate any potential errors.
21) 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.
22) Press the ENTER key to start the automated zero calibration routine.
Note: A waveform will be displayed with “CALC ZERO”, noted in the top right
corner of the display. Once the routine is completed and a stable echo is
displayed, review the waveform quality and polarity selected.
23) Press the ENTER key to store the result - ACCEPT CAL.

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24) Repeat steps 20 – 23 if using the TWO POINT zero calibration option, to
complete the routine for the additional zero cal bar ULTRASONIC 2.
Note: The operator can run the ultrasonic routine as many times as is needed, or
until comfortable with the results. When satisfied with the results, it’s time to
calculate the zero.
25) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the sub menu items until CALC ZERO is highlighted.
26) Press the ENTER key to calculate the zero and display the PROBE
DIAMETER list box. The diameter should be noted on the transducer housing.
27) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll the probe diameter options.
28) Press the ENTER key to select the probe diameter.
Note: This will be automatically documented in the CAL_ZERO_DATA project
data file.

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Important: Only if the glass block and two point calibration options were used as
the as the calibration standard and method, with the intension of recording all
three sides of the glass block, make a note of the velocity value calculated
prior to exiting the calibration menu. The material velocity in the MATL menu
will be edited to match the calculated calibration velocity later in section 1.6,
and in order to obtain/record an accurate measurement for the 2” side of the
glass block.
29) Press the MEAS key to exit the CAL menu and return to the main
measurement screen.
Note: The system zero calibration routine just performed is entirely independent
of the bolt measurement section. Therefore, be sure the MAX II is setup for
the actual bolts intended prior to measurement.
1.6 Verification of System Zero Calibration
The system zero can be verified either immediately following completion of one of the
zero calibration methods described in the previous sections, prior to starting a
new/existing job, or because the hardware has been changed in some way (gauge,
transducer, or cable).
Note: If the glass block was used in conjunction with the two point calibration method,
with the intension of using all three points (1”, 2”, 3”), recordation of the 2” side of the
block can also be stored/documented using this procedure to access the CALZERO
group data file. However, in order achieve an accurate result, the velocity calculated at
the end of the zero calibration procedure must be entered as the velocity in the MATL
menu. The zero calibration section is independent of the ‘live’ measurement section.
Additionally, the approximate length must changed to capture the 2” side of the glass
block.
The procedure below will guide the operator through changing the velocity &
approximate length prior to opening the CALZERO group data file:
Changing Material Velocity & Approximate Length

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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 sub menu
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 VELOCITY is highlighted.
3) Press the ENTER key to display the Digits Edit Box and adjust the
VELOCITY to the Zero Calibration velocity calculated.
4) Press the UP, DOWN, LEFT, & RIGHT arrow keys multiple times using
the left or right button wheel to scroll the highlighted value until the desired
VELOCITY is correctly displayed.
5) Press the OK key to save the VELOCITY and display the material menu
items.

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6) 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 sub menu
items. Alternatively, press the LEFT and RIGHT arrow keys multiple
times using the left button wheel.
7) 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.
8) Press the ENTER key to display the Digits Edit Box and adjust the APPROX
LEN for 2” to find the correct length.
9) Press the UP, DOWN, LEFT, & RIGHT arrow keys multiple times using
the left or right button wheel to scroll the highlighted value until the desired
VELOCITY is correctly displayed.
10) Press the OK key to save the APPROX LEN and display the AUTO menu
items.

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Note: Proceed to the verification section as a guide to access and open the
CAL_ZERO_DATA project, CALZERO data group, and record the 2” side of
the glass block. Follow steps 1 – 9, The procedure for recording the 2” point
will be at the ‘end’ of the verification section. However, start from the
beginning to open the group data file.
Caution:
A very small amount of “WATER”, or other non-intrusive fluid with a similar viscosity,
should be used as the couplant between the transducer and calibration standard
selected. This will avoid creating a couplant film layer between them and cause an “out
of tolerance” condition > +/- 0.001” for the 3” & 6” cal bars, or +/- 0.0005” for the triple
path glass block.
The procedure is as follows:
Verify System Zero Calibration
1) 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 sub menu
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 PROJECT is highlighted.

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3) Press the ENTER key to display the PROJECT list items.
4) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the sub menu items until CAL_ZERO_DATA is
highlighted.
5) Press the ENTER key to display the Confirmation screen, followed by pressing
the OK key to change the project folder.
6) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the menu items until OPEN is highlighted.

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7) Press the ENTER key to display the Cal Zero group data files in the project.
Note: The last group log in the list will contain the most recent zero calibration
data.
CALZERO211202_132519 Date(yr/month/day)_Time(hr/min/sec)
8) Press the UP and DOWN arrow keys multiple times using the left button
wheel to scroll through the log files until the appropriate log file is highlighted.
9) Press the ENTER key to display the highlighted CALZERO group log file.
10) Press the UP, DOWN, LEFT, & RIGHT arrow keys multiple times using
the left button wheel to scroll the cursor to an empty elongation column B–K on
row #2 to verify the 3” Cal Bar.
Note: Clean the surface of the Cal Bar & Transducer thoroughly, apply a small
drop of WATER, or other non-intrusive fluid with a similar viscosity on the Cal
Bar, and attach the transducer to the Cal Bar. Rotate and maneuver the
transducer searching for the absolute minimum elongation possible. If the

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minimum elongation achieved is greater than 0.001”, repeat the zero
calibration procedure to establish a new system zero.
11) Press the ENTER key to store the minimum elongation value, as
reference/record that the calibration was verified.
12) Repeat steps 10 & 11 for the 6” Cal Bar, to verify and document the elongation
value.
Glass Block – Storing 2” Side
1) Press the UP, DOWN, LEFT, & RIGHT arrow keys multiple times using
the left button wheel to scroll the cursor to an empty L-REF cell in column A,
row #4 – 6.
Note: Clean the surface of the 2” side of the Glass Block thoroughly. Apply a
small drop of WATER, or other non-intrusive fluid with a similar viscosity, in
the center of the 2” side and attach the transducer to the Glass Block.
2) Press the AUTO SET key to find the 2” echo and optimize the MAX II setup.
Note: Review the waveform and length displayed for a tolerance 0.0005”. Rotate,
maneuver, and vary pressure on the transducer, while searching for a length
that’s inside of allowable tolerance.
3) Press the ENTER key to store/record the 2” side of the glass block.