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OPERATION MANUAL
DAKOTA ULTRASONICS
PPZZXX--77 DDLL
Precision Ultrasonic Data
Logging Thickness Gauge
P/N P-308-0002 Rev 1.10, March 2019
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CONTENTS
CHAPTER ONE INTRODUCTION ...................................................................... 1
DISCLAIMER ......................................................................................................................... 1
1.1
CHAPTER TWO KEYPAD, MENU, DISPLAY & CONNECTORS ..................... 2
2.1
ON/OFF/ENTER KEY… ..................................................................................................... 2
2.2
PRB 0 KEY… ....................................................................................................................... 2
2.3
CAL KEY…. ......................................................................................................................... 3
DATA KEY… ....................................................................................................................... 3
2.4
2.5
CLR KEY…. ......................................................................................................................... 3
2.6
+/- INCREMENT/DECREMENT KEY’S…. .................................................................................. 3
2.7
MODE KEY…. ..................................................................................................................... 3
2.8
MENU KEY…. ..................................................................................................................... 4
2.9
THE DISPLAY ....................................................................................................................... 5
THE TRANSDUCER .............................................................................................................. 7
2.10
2.11
TOP & BOTTOM END CAPS ................................................................................................. 9
CHAPTER THREE PRINCIPALS OF ULTRASONIC MEASUREMENT ......... 10
3.1
TIME VERSUS THICKNESS RELATIONSHIP ............................................................................. 10
3.2
SUITABILITY OF MATERIALS ................................................................................................. 10
RANGE OF MEASUREMENT AND ACCURACY .......................................................................... 10
3.3
3.4
COUPLANT ......................................................................................................................... 10
3.5
TEMPERATURE ................................................................................................................... 11
3.6
MEASUREMENT MODES ...................................................................................................... 11
CHAPTER FOUR SELECTING THE MEASUREMENT MODE ....................... 13
4.1
WHICH MODE & TRANSDUCER DO I USE FOR MY APPLICATION? ............................................ 13
CHAPTER FIVE MAKING MEASUREMENTS ................................................. 15
5.1
PROBE ZERO ...................................................................................................................... 15
5.2
MATERIAL CALIBRATION ..................................................................................................... 16
CHAPTER SIX THROUGH PAINT MEASUREMENT ...................................... 24
6.1
INTRODUCTION ................................................................................................................... 24
MULTI MODE TRANSDUCERS .............................................................................................. 24
6.2
CHAPTER SEVEN VELOCITY GAUGE ........................................................... 26
7.1
VELOCITY GAUGE (VX) ....................................................................................................... 26
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7.2 CALIBRATION TO A KNOWN THICKNESS ................................................................................ 27
7.3
CALIBRATION TO A KNOWN VELOCITY .................................................................................. 28
CHAPTER EIGHT ADDITIONAL FEATURES ................................................. 30
8.1
GAIN ................................................................................................................................. 30
8.2
HIGH SPEED SCAN ............................................................................................................. 31
8.3
ALARM ............................................................................................................................... 32
8.4
DIFFERENTIAL .................................................................................................................... 33
8.5
UNITS ................................................................................................................................ 34
8.6
LITE ................................................................................................................................... 36
BEEP ................................................................................................................................. 37
8.7
8.8
PROBE TYPE ...................................................................................................................... 38
8.9
VELOCITY (VX) .................................................................................................................. 39
8.10
LOCK ............................................................................................................................... 40
8.11
FACTORY DEFAULTS ........................................................................................................ 40
CHAPTER NINE DATA STORAGE ................................................................. 42
9.1
INTRODUCTION .................................................................................................................. 42
9.2
OPENING A DATA FILE ........................................................................................................ 42
9.3
STORING A MEASUREMENT ................................................................................................ 43
9.4
CLEARING A FILE ............................................................................................................... 44
CLEAR ALL FILES ............................................................................................................... 45
9.5
CHAPTER TEN DATA TRANSFER & POWER OPTIONS.............................. 47
10.1
CONNECTIVITY ................................................................................................................. 47
10.2
OPENING A FILE ............................................................................................................... 47
10.3
COPYING/OPENING FILES ................................................................................................. 47
10.4
LINE POWER .................................................................................................................... 48
APPENDIX A - VELOCITY TABLE .................................................................. 49
APPENDIX B- APPLICATION NOTES ........................................................... 51
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CHAPTER ONE
INTRODUCTION
The Dakota Ultrasonics model PZX-7 DL is a precision ultrasonic micrometer. Based
on the same operating principles as SONAR, the PZX-7 DL is capable of measuring
the thickness of various materials with accuracy as high as 0.0001 inches, or
0.001 millimeters. The principle advantage of ultrasonic measurement over
traditional methods is that ultrasonic measurements can be performed with access to
only one side
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:
of the material being measured.
Dakota Ultrasonics Corporation
1500 Green Hills Road, #107
Scotts Valley, CA 95066
Tel: (831) 431-9722
Fax: (831) 431-9723
www.dakotaultrasonics.com
1.1 Disclaimer
While the PZX-7 DL is a basic digital instrument, it is equipped with a number of
measurement modes and transducer options for additional versatility. It is strongly
recommended that the contents of this manual be read in its entirety to avoid
erroneous measurements based on operator error. The user is solely responsible for
proper use, setup and interpretation of the measurements acquired.
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CHAPTER TWO
KEYPAD, MENU, DISPLAY & CONNECTORS
The Keypad
2.1 ON/OFF/ENTER Key
The ON/OFF/ENTER key powers the unit ON or OFF. Since the same key is also
used as an ENTER key, the gauge is powered off by pressing and holding down the
key until the unit powers off.
Once the gauge is initially powered on, this key will function as the ENTER key,
similar to a computer keyboard. This key will be used to select or set a menu option.
Note: Unit will automatically power off when idle for 5 minutes. All current settings
are automatically saved prior to powering off.
2.2 PRB 0 Key
The PRB 0 key is used to “zero” the PZX-7 DL in much the same way that a
mechanical micrometer is zeroed. If the gauge is not zeroed correctly, all of the
measurements that the gauge makes may be in error by some fixed value. This
feature is only used when using single element contact transducers. Refer to page
15 for a further explanation of this important feature.
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2.3 CAL Key
The CAL key is used to enter and exit the PZX-7 DL's calibration mode. This mode
is used to adjust the sound velocity value that the PZX-7 DL will use when calculating
thickness. The tool will either calculate the sound-velocity from a sample of the
material being measured, or allow a known velocity value to be entered directly. This
provides increased linearity between transducers. Refer to page 16 for an
explanation on the various calibration options.
2.4 DATA Key
The DATA key accesses the data logging section of the PZX-7 DL, which consists of
50 sequential (single column) files with 250 storage locations per file. Refer to page
42 for an explanation on the various calibration options.
2.5 CLR Key
The CLR key is used in conjunction with the data logging section to clear a single
stored memory location. Refer to page 42 for an explanation on the various
calibration options.
2.6 +/- Increment/Decrement Key’s
The +/- Keys are used to increment/decrement values, navigate menus, select menu
options, and navigate data files and storage locations.
2.7 MODE Key
The MODE key toggles the measurement modes. If a delay line transducer (dLY) is
selected from the PROB menu option, echo-echo (E-E) and interface-echo (I-E)
modes will be toggled. If a contact transducer (Con) is selected, pulse-echo (P-E)
and echo-echo (E-E) modes will be toggled. Finally, if the plastic transducer (PLAS)
option is selected, the thickness options thin (thin) and thick (thK) will be toggled. The
measurement modes and transducer styles offer the flexibility to address specific
application scenarios. Refer to page 11 for an explanation on the various calibration
options.
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2.8 MENU Key
The MENU key is used to access and set all of the additional features of the PZX-7
DL that are not at the top level of the keypad with a dedicated key. The features and
setting are outlined in the table below:
Menu Feature Items:
Gain Matl Scan Alarm Diff Unit Lite Beep Probe VX
VLOW * Aluminum On On On English On On Delay On
LOW Steel Off Off Off Metric Off Off Plastic Off
MED Stainless Options Options Options Options Contact
HIGH Iron Set Lo Set
Nominal
VHI * Plexiglass Set Hi HIGH Med .12 5
PVC High .12 10
Plastic .25 5
Poly Urea .25 10
User 1 .37 5
User 2 .50 5
.50 10
LOW Lo Options
**
* Displayed only when the contact transducer option has been selected.
** Diameter options are only available for contact transducers.
Here’s a quick overview of navigating through the various features in MENU:
Navigating the Features in Menu
1) Press the key once to enter the sub menu items.
2) Press the keys to toggle through the features.
3) To enable or edit the status of any feature, press the key.
4) The edit icon will start blinking to indicate that the PZX-7 DL is currently in
EDIT mode.
5) Press the keys to toggle through the setting options.
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PZX-7 DL Ultrasonic Thickness Gauge
6) Press the key to accept changes and return to the top level of
features, or the key at any time to abort changes and return the
measurement screen.
2.9 The Display
The PZX-7 DL uses a custom glass LCD backlit low temperature display for use in a
variety of climate conditions. It contains graphic icons, as well as both 7 and 14
segment display areas. Let’s take a closer look and what all these things are telling
us:
A. Edit: This icon will be displayed, and blinking, to let a user know when they
are in an edit mode to change a value or setting.
B. Large 7 segment:
will be displayed in this area.
C. Measurement Modes: This group of icons indicates which measurement
mode the PZX-7 DL is currently using. The modes are pulse-echo, echo-
echo, interface-echo, and plastics (PLAS).
D. Stability/Repeatability Indicator: This is used in conjunction with the
thickness measurement as a reference for the validity of the measurement.
The PZX-7 DL takes multiple measurements per second, and when all the
The thickness measurement, velocity or alpha message
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vertical bars are illuminated, it’s a reference that the same thickness value is
reliably being measured multiple times per second.
E. Battery: Indicates the amount of battery life the PZX-7 DL has remaining.
F. Backlight : When this icon is illuminated, it indicates the backlight is on.
G. Small 7 Segment:
through a given medium/material, is displayed in this area, informing the user
what material the PZX-7 DL is currently calibrated too. This area is also used
for alpha messages in the menu and edit modes.
H. Units:
inform the user what measurement units are currently being displayed in the
small 7 segment area.
I. Small 14 Segment: Displays the current gain setting of the PZX-7 DL. In P-E
mode the options are VLOW, LOW, MED, HIGH, VHI, and LOW, MED, HIGH
with modes E-E, I-E, and PLAS. MED is the default setting.
J. Units: This combination of icons are illuminated in different sequences to
inform the user what measurement units are currently being displayed in the
large 7 segment area. The plus/minus icon is illuminated when the DIFF
(differential) feature is activated.
K. Small 14 Segment: The material type is displayed in this area. If it is set to a
value of one of the materials in our material list, it will be displayed in alpha
characters indicating the material type. Otherwise it will be set to CUST,
indicating custom material type.
L. Features: The icons illuminated in this row across the bottom of the LCD
display which features are currently enabled. For a complete list of the menu
features in the PZX-7 DL, Refer to page 4 for a list. The PZX-7 DL can be
locked once calibrated, to avoid accidently changing the calibration. When
this icon is illuminated, the PZX-7 DL is in lock mode. Refer to page 40 for an
explanation on locking the PZX-7 DL.
M. File/Loc:
DL. The icons and segment fields represent the current file open, and the
current storage location in the file. Refer to page 42 for an explanation of the
data storage feature in the PZX-7 DL.
This combination of icons are illuminated in different sequences to
This area is exclusively for the data storage section of the PZX-7
The material velocity, speed the sound wave travels
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2.10 The Transducer
Delay Line Contact
The Transducer is the “business end” of the PZX-7 DL. It transmits and receives
ultrasonic sound waves that the PZX-7 DL uses to calculate the thickness of the
material being measured. The transducer connects to the PZX-7 DL using a single
shielded coaxial cable with microdot connectors.
Delay Line Transducer
The single element delay line transducer is commonly used with the PZX-7 DL for
materials with an approximate range of 0.006” to 1.00” in steel. The measurement
modes used with this style of transducer are echo-echo (E-E) and interface-echo (IE). Echo-echo mode will be used for the lower end of the measurement range, while
interface-echo for the upper end of the measurement range. Interface-echo mode
measures from the end of the delay line to the first return echo from the back wall of
the material, while echo-echo measurements are made between the first and second
return echoes from the back wall of the material. The frequency range for the
versions Dakota commonly supply are from 10MHz to 20MHz.
The Delay line is fastened to the transducer with a retaining ring. A drop of couplant
is applied between the delay line and transducer body. Refer to the diagram above.
The couplant should be checked on a regular basis to keep it from drying out. To
replenish, unscrew the retaining ring counterclockwise, separate the delay line from
the body, ‘clean both surfaces’, apply a drop of couplant, and reassemble.
Delay Line Graphite Tip (For use with Plastics Mode)
The PZX-7 DL has a special “PLAS” mode that uses the standard delay line
transducer, as described above, but with a replaceable graphite delay tip. This mode
and tip should be used when the velocity of the plastic material measured is similar to
the velocity of the standard acrylic delay tip, and not achieving any
signal/measurement. The graphite tip creates a ‘mismatch’ between the tip material
and the plastic material measured.
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The Delay line is fastened to the transducer with a retaining ring. A drop of couplant
is applied between the delay line and transducer body. Refer to the diagram above.
The couplant should be checked on a regular basis to keep it from drying out. To
replenish, unscrew the retaining ring counterclockwise, separate the delay line from
the body, ‘clean both surfaces’, apply a drop of couplant, and reassemble.
Contact Transducer
The single element contact style transducers are commonly used for materials with
an approximate range of 0.040” to the maximum range of the PZX-7 DL rated in steel
and depending on the transducers diameter and frequency. The frequency range is
5.0 to 10 MHz, with diameters available at 0.125, 0.250, 0.375 and 0.500 inches.
The measurement modes used with this style of transducer are pulse-echo (P-E) and
echo-echo (E-E).
Measuring
In order for the transducer to do its job, there must be no air gaps between the wearface and the surface of the material being measured. This is accomplished with the
use of a "coupling" fluid, commonly called "couplant". This fluid serves to "couple", or
transfer, the ultrasonic sound waves from the transducer, into the material, and back
again. Before attempting to make a measurement, a small amount of couplant
should be applied to the surface of the material being measured. Typically, a single
droplet of couplant is sufficient.
After applying couplant, press the transducer (wear face down) firmly against the
area to be measured. The Stability Indicator should have six or seven bars
darkened, and a number should appear in the display. If the PZX-7 DL has been
properly "zeroed" (see page 15), only if P-E mode is currently selected, and set to the
correct sound velocity (see page 16), the number in the display will indicate the
actual thickness of the material directly beneath the transducer.
If the Stability Indicator has fewer than five bars darkened, or the numbers on the
display seem erratic, first check to make sure that there is an adequate film of
couplant beneath the transducer, and that the transducer is seated flat against the
material. If the condition persists, it may be necessary to select a different transducer
(size or frequency) for the material being measured. See page 13 for information on
transducer selection.
While the transducer is in contact with the material that is being measured, the PZX-7
DL will perform four measurements every second, updating its display as it does so.
When the transducer is removed from the surface, the display will hold the last
measurement made.
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2.11 Top & Bottom End Caps
The top & bottom end panels are where all connections are made to the PZX-7 DL.
The diagram above shows the layout and description of the connectors:
Transducer Connector
Refer to Diagram: The transducer connector and battery cover/probe zero disk are
located on the PZX-7 DL’s top end cap. The transducer connector is a Lemo “00”.
Probe Zero Disk & Battery Cover
Refer to Diagram: The Battery cover is the large round disk shown in the diagram.
Note: This same disk is also used as a probe zero disk when the zero feature is set
to the ‘manual’ option. Simply remove the cover when replacing the batteries (2 AA
cells). When performing a manual probe zero function, simply place the transducer
on disk making firm contact. Important: Be sure the battery polarity is correct,
which can be found on the back label of the PZX-7 DL.
Note: Rechargeable batteries can be used, however they must be recharged outside
of the unit in a standalone battery charger.
USB-C Connector
Refer to Diagram: The USB-C connector, located on the bottom end cap, is a mini
type C female connector. It is designed to connect directly from the PZX-7 DL to a
standard USB type A port on a PC. The cable supplied with the PZX-7 DL is a USB
type C to a USB type A (pt# N-003-0330). See page 47 for information on
connectivity.
Note: This connector is also used to upgrade the PZX-7 DL with the latest version of
firmware.
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CHAPTER THREE
PRINCIPALS OF ULTRASONIC MEASUREMENT
3.1 Time versus thickness relationship
Ultrasonic thickness measurements depend on measuring the length of time it takes
for sound to travel through the material being tested. The ratio of the thickness
versus the time is known as the sound velocity. In order to make accurate
measurements, a sound velocity must be determined and entered into the
instrument.
The accuracy of a thickness measurement therefore depends on having a consistent
sound velocity. Some materials are not as consistent as others and accuracy will be
marginal. For example, some cast materials are very granular and porous and as a
result have inconsistent sound velocities.
While there are many different ultrasonic techniques to measure thickness, which will
be discussed below, all of them rely on using the sound velocity to convert from time
to thickness.
3.2 Suitability of materials
Ultrasonic thickness measurements rely on passing a sound wave through the
material being measured. Not all materials are good at transmitting sound.
Ultrasonic thickness measurement is practical in a wide variety of materials including
metals, plastics, and glass. Materials that are difficult include some cast materials,
concrete, wood, fiberglass, and some rubber.
3.3 Range of measurement and accuracy
The overall measurement capabilities, based on the wide variety of materials, are
determined by the consistency of the material being measured (homogeneity). The
range of thickness that can be measured ultrasonically depends on the material type
and surface, as well as the technique being used and the type of transducer and
frequency. The range will vary depending on the type of material being measured.
Accuracy, is determined by how consistent the sound velocity is through the sound
path being measured, and is a function of the overall thickness of the material. For
example, the velocity in steel is typically within 0.5% while the velocity in cast iron
can vary by 4%.
3.4 Couplant
All ultrasonic applications require some medium to couple the sound from the
transducer to the test piece. Typically a high viscosity liquid is used as the medium.
The sound frequencies used in ultrasonic thickness measurement do not travel
through air efficiently. By using a liquid couplant between the transducer and test
piece the amount of ultrasound entering the test piece is much greater.
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3.5 Temperature
Temperature has an effect on sound velocity. The higher the temperature, the slower
sound travels in a material. High temperatures can also damage transducers and
present a problem for various liquid couplants.
Since the sound velocity varies with temperature it is important to calibrate at the
same temperature as the material being measured.
Normal temperature range
Most standard transducers will operate from 0F to 150F.
High temperature measurements
Special transducers and couplants are available for temperatures above 150F with
intermittent contact in some cases. It is necessary to cool the transducer by
submerging it in water between measurements.
Modes and temperature errors
In addition to errors caused by velocity changing with temperature, some modes
(measurement techniques) are affected more than others. Multi-echo techniques
offer temperature compensation to help minimize these errors.
3.6 Measurement Modes
This section will cover the different measurement modes of the PZX-7 DL, the
transducers required, and the reasons for using specific modes:
Pulse-Echo (P-E) Mode:
Pulse-echo mode measures from the initial pulse (sometimes referred to as an
artificial zero) to the first echo (reflection), and is only used if the transducer type is
set to contact mode. In this mode, a manual zero using the disk (battery cover) will
need to be performed prior to calibrating the PZX-7 DL. The transducer is placed on
the reference disk located on top of the PZX-7 DL, and the PRB 0 key pressed to
establish a zero point for the transducer connected.
Errors from surface coatings and temperature variations can occur in pulse-echo
mode. Therefore, coatings should be removed, and frequent probe zero’s should be
performed if experiencing temperature gradients.
Echo-Echo (E-E) Mode – Through paint
The echo-echo mode measures between the first and second return
echoes/reflections. This mode is most commonly used with the high frequency delay
line style transducers for thin materials, and will also eliminate compensate for
temperature. This technique will also eliminate error due to epoxy based coated
surfaces by eliminating the error from the coating and measuring only the second
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layer or base material without having to remove the coating. The disadvantage is
that two return echoes are required to effectively measure the test material. As a
result, the type and thickness of the coating will affect the ability to achieve a
successful measurement. Both delay line and contact style transducers can be used
for through paint/coating measurements.
Interface-Echo (I-E) Mode
The interface-echo mode measures from the end of the “‘interface/delay line” to the
first return echo/reflection. This mode can be used for thicker materials up to 1”, and
for attenuative materials that don’t produce a sufficient second echo. The standard
measuring range is approximately 0.060” up to 1.00” rated in steel, and offers
temperature compensation for the heating and cooling of the transducer itself.
Plastics (PLAS) Mode
The plastics mode is a special setup for measuring thin plastics using a modified
interface-echo mode. When the standard acrylic delay tip is similar in velocity to the
plastic material measured, a return echo is not possible. Simply replacing the acrylic
tip with our graphite tip and using the ‘plastics’ mode will provide the necessary
mismatch necessary to measure the plastic successfully. The approximate range is
0.005” up to 0.300” depending on the type of plastic measured. This mode
additionally offers temperature compensation for the heating and cooling of the
transducer.
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CHAPTER FOUR
SELECTING THE MEASUREMENT MODE
4.1 Which mode & transducer do I use for my application?
High penetration plastics and castings
The most common mode for these types of applications is pulse-echo. Thicker cast
iron and plastics applications will generally require lower frequencies depending on
the material type and thickness. Frequencies from 5MHz to 10MHz are common.
Larger diameters offer greater penetration power based on the size of the crystal.
Thin Materials & Tough Access Areas
The high frequency delay line transducers are suitable when measuring thinner
consistent materials that pass sound easily, such as steel, aluminum, titanium, etc.
They offer temperature compensation with a suitable range up to 1” depending on
the delay line used. Replaceable cone tip options are also useful for difficult access
areas and diameters.
Thru Paint & Coatings
It’s common that users will be faced with applications where the material will be
coated with some type of protective paint or other epoxy based material. Since the
velocity of the coating is approximately 3 times slower than that of steel, pulse-echo
mode will produce an error if not removed. However, echo-echo mode can be used
with either delay line or contact style transducers to eliminate the error from the
coating, and measure only the base material. High damped or high frequency
transducers are most suitable for echo-echo measurement mode.
Plastics
Thin plastics are best suited using the delay line transducer with either the acrylic
delay tip in echo-echo or interface-echo modes. If the plastic measured is similar in
velocity to the acrylic tip and not measuring adequately, the replaceable graphite tip
and plastics mode will serve as the best option. Thicker plastics will generally require
a lower frequency contact style transducer for additional penetration. Increasing the
diameter of the transducer will also offer greater output.
High temperature
High temperature applications will require a special delay line material that isn’t as
absorptive of temperature.
Noisy Material
Materials such as titanium, stainless steel, and aluminum may have inherent surface
noise issues (mirroring effect). This can be avoided using a high frequency delay line
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transducer in either echo-echo or interface-echo modes. If using a contact style
transducer, a high frequency option should be considered.
Restricted access
Measuring materials with extreme curvatures or restricted access are best suited for
higher frequencies and smaller diameter transducers or tip options.
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CHAPTER FIVE
MAKING MEASUREMENTS
The steps involved in making measurements are detailed in this section. The
following sections outline how to setup and prepare your PZX-7 DL for field use.
In pulse-echo mode the probe zero must be performed on the reference disk (battery
disk) attached to the top of the instrument. This compensates for variation in the
transducer. In all modes the sound velocity must be determined. The sound velocity
is used to convert the transit time to a physical length. The sound velocity can be
selected from the material chart at the end of this manual, or for greater precision
determined by measuring and calibrating from a known thickness of the actual
material. To enter the velocity from a table, look up the material on the chart in the
appendix of this manual and refer to the section below on Calibration to a Known
Velocity. To determine the velocity of a single sample, refer to the Material
Calibration section on page 16.
When measuring curved materials, it’s more accurate to calibrate from two test
points, one at the minimum limit of the target thickness and one at the maximum limit.
In this case the reference disk is not used, and considered a ‘two-point’ calibration
described on page 19.
5.1 Probe zero
A probe zero is only necessary if a contact style transducer is used in pulse-echo
mode, and the contact option is enabled in the menu. A probe zero should be done
prior to calibrating the instrument, and done on a periodic basis when a temperature
gradient is an issue. If the PZX-7 DL is not zeroed correctly, all measurements will
be in error by some fixed value. In order to perform a probe zero, you must be in
pulse-echo mode.
Setting the zero point of the PZX-7 DL is important for the same reason that setting
the zero on a mechanical micrometer is important. It must be done prior to
calibration, and should be done throughout the day to account for any temperature
changes in the probe. If the PZX-7 DL is not zeroed correctly, all the measurements
taken may be in error by some fixed value. The zero can only be performed with the
measurement mode set to pulse-echo (P-E). Therefore, if the PZX-7 DL is to use the
echo-echo (E-E) measurement mode and a manual zero is being performed, the
PZX-7 DL will argue by briefly displaying the message “nO prB0” (no probe zero),
and automatically switch modes to pulse-echo (P-E) where a zero can be performed.
The procedure to zero the transducer is outlined as below:
Performing a Manual Probe Zero (On Block)
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1) Apply a drop of couplant on the transducer and place the transducer in
steady contact with the disk (battery cover) located at the top of the unit to
obtain a measurement.
2) Be sure all six repeatability/stability bars in the top left corner of the display
are fully illuminated and stable, and last digit of the measurement is toggling
only +/- .001” (.01mm).
3) Press the key to perform the manual zero. “PRB0” will briefly be
displayed on the screen, indicating the zero calculation is being performed.
5.2 Material Calibration
In order for the PZX-7 DL to make accurate measurements, it must be set to the
correct sound velocity of the material being measured. Different types of materials
have different inherent sound velocities. For example, the velocity of sound through
steel is about 0.233 inches per microsecond, versus that of aluminum, which is about
0.248 inches per microsecond. If the gauge is not set to the correct sound velocity,
all of the measurements the gauge makes will be erroneous by some amount.
The One Point calibration is the simplest and most commonly used calibration
method - optimizing linearity over large
greater accuracy over small
material velocity. The PZX-7 DL provides three simple methods for setting the
sound-velocity outlined below:
ranges by calculating both the probe zero, as well as the
ranges. The Two Point calibration allows for
Known Velocity
If the material velocity is known, it can be manually entered into the PZX-7 DL, rather
than have the PZX-7 DL calculate the velocity value using a known thickness of the
same material type. The steps for entering the velocity are outlined below:
Using a Known Material Velocity
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1) With the transducer free from contact with the material, press the key
to display the current velocity.
2) Use the keys to scroll the velocity to the known target
value.
Note: The longer the keys are pressed and held, the faster the value will
increment/decrement.
Note: Pressing the key prior to pressing the key will abort the cal
routine without saving any changes.
3) Press the key to set the velocity value and return to the measurement
screen. The new velocity value will be shown at the top of the display.
Known Thickness
Often times the exact sound velocity of a material is unknown. However, a sample
with one or two known thicknesses can be used to determine the sound velocity. As
previously discussed, the PZX-7 DL has a one or two point calibration option. The
one point calibration option is most suited for linearity over large ranges. When using
the one point option, the calibration should be perform on the thickest side of the
measurement range for the best linearity for that range. For example, if the
measurement range is .100” (2.54mm) to 1.0” (25.4mm), the user should calibrate on
a known thickness sample close to 1.0” (25.4mm). Note: It’s always handy to carry
a set of mechanical calipers to use in conjunction with the PZX-7 DL for calibration of
various materials in the field:
One Point Calibration
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Note: Be sure that a probe zero has been performed prior to performing this
calibration procedure.
1) Physically measure an exact sample of the material, or a location directly on
the material to be measured, using a set of calipers or a digital micrometer.
Note: A sample or location on the test piece should be used as close to the
maximum thickness of the test range to minimize error.
2) Apply a drop of couplant on the transducer and place the transducer in
steady contact with the sample or actual test material. Be sure that the
reading is stable and the repeatability indicator in the top left corner of the
display is fully lit and stable.
3) Press the key to enter the calibration edit screen displaying the current
measurement value.
4) Use the keys to scroll to the known thickness value.
Note: The longer the keys are pressed and held, the faster the value will
increment/decrement.
Note: Pressing the key prior to pressing the key will abort the cal
routine without saving any changes.
5) Once the known thickness value is being displayed, press the key to
display the calculated material velocity edit screen.
Note: The calculated velocity can be edited, if needed, by pressing the
keys to scroll and edit the velocity value.
6) Press the key to set the calculated material velocity and return to the
measurement screen.
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Note: CHECK YOUR CALIBRATION! Place the transducer back on the
calibration point and verify the thickness. If the thickness is not correct, repeat
the steps above.
Two Known Thicknesses
The two point calibration should be considered when an application requires
improved accuracy over a small measurement range based on tolerance
requirements. This calibration option calculates both the ‘probe zero’ and ‘velocity
value. If the two point option is used, a probe zero is not required. For example, if
the measurement range was .080” (2.03mm) to .250” (6.35mm), two known samples
or locations on the test material would be needed for the minimum and maximum
boundaries of the test range. Using the range above, a one point calibration would
be performed at .250” (6.35mm) and a two point calibration at .080” (2.03mm), or
something close to the min/max values of the measurement range.
Note: The PZX-7 DL also offers the capability of setting the ‘probe zero’ to use any
reference standard as the ‘probe zero’ standard. For clarification, if it’s desired to use
a one inch reference of a specific material type as the ‘zero’ reference, performing
the first point of a two-point calibration sets the internal zero of the PZX-7 DL. This
should be used only in manual probe zero mode “on block”. This can be done in ‘all’
measurement modes to correct the zero or offset as needed/required.
The following steps outline this procedure:
Two Point Calibration
1) Physically measure a minimum and maximum calibration point of the exact
sample material, or locations directly on the material to be measured, using
a set of calipers or a digital micrometer.
Note: A sample or location on the test piece should be used as close to the
minimum and maximum thickness of the test range to minimize error and
improve linearity.
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2) Apply a drop of couplant on the transducer and place the transducer in
steady contact with either the minimum or maximum sample or actual test
material. Be sure that the reading is stable and the repeatability indicator in
the top left corner of the display is fully lit and stable.
3) Press the key to enter the calibration edit screen displaying the current
measurement value.
4) Use the keys to scroll to the known thickness value.
Note: The longer the keys are pressed and held, the faster the value will
increment/decrement.
Note: Pressing the key prior to pressing the key will abort the cal
routine without saving any changes.
5) Once the known thickness value is being displayed, press the key to
display “1 of 2”, which sets the zero value and returns to the measurement
screen.
Note: The internal zero of the PZX-7 DL is now set. The procedure above can
be used in all measurement modes to set the internal zero or offset of the
PZX-7 DL to use any reference standard as the ‘probe zero’ standard if
desired.
6) Repeat steps 2-4 on the second test point/location.
7) Press the key to display the calculated velocity edit screen.
Note: The calculated velocity can be edited, if needed, by pressing the
keys to scroll and edit the velocity value.
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8) Press the key to set the calculated material velocity and return to the
measurement screen.
Note: CHECK YOUR CALIBRATION! Place the transducer back on the
calibration points. The thickness readings should now match the known
thickness values with minimal error. If the thicknesses are not correct, repeat
the steps above.
Basic Material Type
If the material velocity is unknown, a sample thickness cannot be taken directly from
the material, but the general type of material is known, selecting a basic material type
from the common material (MATL) list in the PZX-7 DL would offer a reasonable
approximation of the thickness. There are 9 common materials and 2 user
programmable settings available. It’s important to note that these velocities will not
always be an exact representation of the material being tested. Use these values
only if a close approximation is acceptable. Follow the steps below to select a basic
material type:
Selecting a Basic Material Type
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
MATL feature is being displayed.
3) Press the key to edit the material setting. The edit icon will be
illuminated and flashing.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving any changes.
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4) Use the
keys to scroll through the material options.
in/µs m/s
ALUMINUM
(2024)
STEEL (4340)
STAINLESS (303)
CAST IRON
PLEXIGLASS
PVC
POLYSTYRENE
POLYURETHANE
USER PROGRAMMABLE
0.250 6350
0.233 5918
0.223 5664
0.180 4572
0.106 2692
0.094 2388
0.092 2337
0.070 1778
5) When the desired MATL setting is displayed, press the key to set the
material velocity and return to the measurement screen.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving any changes.
6) If USR1 or USR2 were selected, the velocity edit screen will be displayed
and edit icon illuminated and flashing.
7) Use the keys to scroll to the desired material velocity.
Note: The longer these keys are held, the faster the velocity value is
incremented.
8) When the desired velocity setting is displayed, press the key to set the
material velocity and return to the measurement screen.
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9) Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving any changes.
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CHAPTER SIX
THROUGH PAINT MEASUREMENT
6.1 Introduction
Through paint measurement is accomplished by measuring the time between two
repeat echoes from the back surface of the material. Since both of these back wall
echoes travel the same path through the paint or coating, the thickness of the coating
is subtracted out of the measurement so that only the actual material thickness is
measured. This avoids having to scrape or remove the coating from materials prior
to inspection. The primary purpose of thru paint measurement is to determine the
actual/nominal material thickness without error from the coating. Finally, this mode
will only work for typical epoxy based coatings.
6.2 Multi Mode Transducers
The multi echo measurement technique does have restrictions on the type of
transducers it can use successfully. The key requirement is that the transducers are
“high damped”, which refers to the duration of how long the transducer rings. In
order to improve the low end measurement range, being able to measure thin
materials, the cycles of ring must be limited so they don’t interfere with the internal
gating.
Since the PZX-7 DL is a basic easy to operate gauge without the adjustability you’d
get using an advanced A-Scan scope, echo-echo mode is subject to limitations
depending on type and thickness of the coating, as well as the type of transducer
used.
The procedure for activating the through paint (E-E) measurement mode is outlined
as follows:
Echo-Echo Multi Mode
Note: Be sure that a probe zero (if using a contact transducer) and “one point
calibration”, or a “two point calibration” has been performed prior to this
procedure.
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1) Press the key to toggle between the measurement modes, for a given
transducer type (contact or delay line), to echo-echo (E-E) mode.
Note: An icon will be illuminated in the top left portion of the display to indicate
the measurement mode the PZX-7 DL is currently using.
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CHAPTER SEVEN
VELOCITY GAUGE
7.1 Velocity Gauge (VX)
The PZX-7 DL includes a function to convert the unit into a dedicated velocity gauge.
With this feature enabled, the PZX-7 DL will display all measurements in terms of
velocity, inches per microsecond (IN /s) or meters per second (M /s), rather than
dimensional inches or millimeters. This is primarily useful for rudimentary “nodularity”
testing, as the velocity can be associated with density and used to determine the
hardness/strength of a given material. A casting manufacturer would typically use
this feature to control their processes and make sure the density/hardness is
sufficient for each part and batch within a specified tolerance.
Using this feature will require calibration on a “known” thickness that will remain
consistent at a specific location on a group of parts. The test will always be
performed at the same location for all parts in the group. The velocity will be
determined, and either accepted or rejected depending on the specified tolerances.
The procedure for enabling this feature is outlined below:
Velocity Gauge Option
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
VX feature is being displayed.
3) Press the key to edit the velocity gauge setting. The edit icon will be
illuminated and flashing.
4) Use the keys to toggle velocity on/off.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
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5) When the desired VX setting is displayed, press the key to set the
status and return to the measurement screen.
7.2 Calibration to a known thickness
In order to calibrate the PZX-7 DL a ‘known thickness’ on the material or part will be
used. The same location will be used for all the other parts in the group/batch to
determine the velocity.
The procedure is outlined as follows:
Calibration – Known Thickness
Note: Be sure that a probe zero has been performed prior to performing this
calibration procedure.
1) Physically measure an exact sample of the material, or a location directly on
the material to be measured, using a set of calipers or a digital micrometer.
2) Apply a drop of couplant on the transducer and place the transducer in
steady contact with the sample or actual test material. Be sure that the
reading is stable and the repeatability indicator, in the top left corner of the
display, is fully lit and stable.
3) Press the key to enter the calibration edit screen displaying the current
velocity IN /s (M /s) value. The edit icon will be illuminated and flashing.
4) Press the key again to edit the known thickness value. The edit icon
will be illuminated and flashing and the units will be IN or MM, indicating
thickness.
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5) Use the keys to scroll to the known thickness value.
Note: The longer the keys are pressed and held, the faster the value will
increment/decrement.
Note: Pressing the key prior to pressing the key will abort the cal
routine without saving any changes.
6) Once the known thickness value is being displayed, press the key to
return to the measurement screen and display the calculated material
velocity.
Note: The known thickness value that was used to calibrate will be displayed in
the top right corner of the display for confirmation.
7.3 Calibration to a known velocity
The velocity can also be directly edited and set to a target velocity value that was
previously determined from a reference standard at an earlier time.
The procedure for directly entering the velocity is outlined below:
Calibration – Known Velocity
Note: Be sure that a probe zero has been performed prior to performing this
calibration procedure.
Note: This procedure requires that the operator know the sound-velocity of the
material to be measured. A table of common materials and their sound-
velocities can be found in Appendix A.
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1) Apply a drop of couplant on the transducer and place the transducer in
steady contact with the sample or actual test material. Be sure that the
velocity measurement is stable and the repeatability indicator, in the top left
corner of the display, is fully lit and stable.
2) Press the key to enter the calibration edit screen displaying the current
velocity IN /s (M /s) value. The edit icon will be illuminated and flashing.
3) Use the keys to scroll to the known velocity value.
Note: Pressing the key prior to pressing the key will abort the cal
routine without saving any changes.
4) Once the known velocity value is being displayed, press the key to
display the calculated thickness based on known velocity.
5) Press the key to return to the measurement screen and begin making
measurements.
Note: The known velocity value that was entered will be displayed, and the
thickness value calculated will appear in the top right corner of the display
for confirmation.
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CHAPTER EIGHT
ADDITIONAL FEATURES
8.1 Gain
The gain, or amplification of the return echoes, can be adjusted in the PZX-7 DL to
accommodate a variety of materials and applications. The setting of the gain is
crucial in order to obtain valid readings during the measurement process. Too much
gain may result in erroneous measurements, detecting on noise rather than the
actual material back wall surface. Not enough gain may result in intermittent
detection. If you turn it up too much, you can’t hear the music clearly. If it’s turned
down too much, you can’t hear it at all.
The PZX-7 DL has the option of using and selecting three different transducer types;
contact, delay line, and plastics. The contact transducers, in pulse-echo (P-E) and
echo-echo (E-E), as well as delay line style transducers in interface-echo (I-E) and
echo-echo (E-E) use automatic gain control (AGC) and fixed time dependent gain
(TDG). They have three gain settings (LOW, MED, HIGH) with a 3dB cut/boost to
the dynamic range of the AGC. Plastics (PLAS) mode, ‘ thin setting only’, uses a
manual gain with five settings (VLOW, LOW, MED, HIGH, VHI) in 3dB increments,
while the delay line style transducers use automatic gain control (AGC), and have 3
gain settings (LOW, MED, HIGH), similar to the contact and delay line style probes.
The PZX-7 DL has been optimized for the MED gain setting for all common
applications. It should be operated in this mode as standard. However, some
applications may require the lower or higher gain settings. When? The low settings
may be necessary for noisy or granular cast materials. How do I know when to lower
the gain? If the reading becomes sporadic and won’t settle down or resolve on a
thickness value because the material is either very noisy or granular. Setting the
gain to a lower less sensitive level, would potentially offer improved stability. How do
I know when to increase the gain? When a material is difficult to penetrate or pass
sound through. This could be due to the material type, overall thickness, the
transducer diameter and frequency, or a combination of all the above. Turning the
gain up for additional output could improve the ability to obtain a successful
measurement. In any case, the selectable gain settings offer improved versatility to
resolve and overcome potential application issues.
Note: When the pulse-echo (P-E), echo-echo (E-E),or plastics (PLAS) “thick plastic
setting option” measurement modes are selected for either contact, delay line, or
plastics modes, The automatic gain control (AGC) is enabled. The dynamic range of
the AGC can be adjusted with the following options (LOW, MED, HIGH), with MED
still being the optimized standard setting as above.
The procedure for adjusting the gain is outlined as follows:
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GAIN
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
GAIN feature is being displayed.
3) Press the key to edit the gain setting. The edit icon will be illuminated
and flashing.
4) Use the keys to scroll through the gain settings in PLAS
“thin setting” (VLOW, LOW, MED, HIGH, VHI), or P-E, E-E, I-E, PLAS “thick
setting” (LOW, MED, HIGH) until the desired setting is being displayed.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
5) Press the key to set the gain and return to the measurement screen.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
8.2 High Speed Scan
The High Speed Scan feature of the PZX-7 DL increases the overall repetition rate to
a maximum of 140Hz with a high speed screen refresh rate of 25 times a second.
This allows for making scanned passes over an arbitrary length of the test material,
while still maintaining a reasonable representation of thickness over the area or
region scanned. The alarm (ALRM) feature, with high and low limits, can be used in
conjunction with high speed scan.
The procedure to use the scan feature is outlined below:
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High Speed Scan
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
SCAN feature is being displayed.
3) Press the key to edit the scan setting. The edit icon will be illuminated
and flashing.
4) Use the keys to toggle scan on/off.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
5) When the desired SCAN setting is displayed, press the key to set the
status and return to the measurement screen.
8.3 Alarm
The Alarm feature of the PZX-7 DL provides a method of setting tolerances, or limits,
for a particular application requirement. This feature may be used for a variety of
applications to verify the material thickness is within the manufacturer specifications.
The settings available are ON/OFF/BEEP, where beep enables the audible beeper.
Both the on and beep settings will illuminate the led alarm lights above the keys on
the keypad. There are two limit values HI/LO, that can be set according to specified
tolerances.
The procedure to use the alarm feature is outlined below:
ALARM
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1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
ALRM feature is being displayed.
3) Press the key to edit the alarm status. The edit icon will be illuminated
and flashing.
4) Use the keys to toggle alarm on/off/beep.
5) When the desired ALRM status is displayed, press the key to set the
status and edit the LO limit option.
6) Use the keys to scroll the LO limit value to the target value.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes to the LO limit value.
7) When the target LO limit is displayed, press the key to set the value
and advance to setting HI limit option.
8) Use the keys to scroll the HI limit value to the target value.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes to the HI limit value.
9) When the target HI limit is displayed, press the key to set the value
and return to the measurement screen.
8.4 Differential
The Differential Mode of the PZX-7 DL provides the user with the ability to set a
nominal value, according to what the expected thickness should be, and measure the
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+/- difference from the nominal value entered. This feature is typically used in QA
incoming inspections on pipes, plate stock, coils, etc.
The steps below outline how to enable and enter the nominal value to use this
feature:
Differential
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
DIFF feature is being displayed.
3) Press the key to edit the differential status. The edit icon will be
illuminated and flashing.
4) Use the keys to toggle differential on/off.
5) When the desired DIFF setting is displayed, press the key to set the
status and edit the NOMINAL value.
6) Use the keys to scroll the NOMINAL value to the target
value.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes to the NOMINAL value.
7) When the target value is displayed, press the key to set the value and
return to the measurement screen.
8.5 Units
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The PZX-7 DL will operate in both English (inches) or Metric (millimeters) units. In
either option the resolution (RES) can be set to LOW (.001in/.01mm), or HIGH
(.0001in/.001mm).
The procedure to select the units is outlined as below:
Units
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
UNIT feature is being displayed.
3) Press the key to edit the units setting. The edit icon will be illuminated
and flashing.
4) Use the keys to toggle English or Metric units.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
5) When the desired UNIT setting is displayed, press the key to set the
units and edit the RES (resolution) option.
6) Use the keys to scroll the RES (LOW, HIGH) options.
7) When the desired RES setting is displayed, press the key to set the
resolution and return to the measurement screen.
8) Note: Pressing the key prior to pressing the key will abort to
the measurement screen without saving changes.
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8.6 Lite
The PZX-7 DL uses a custom glass segmented display that is equipped with a
backlight for use in low light conditions. The options are on/off/auto, where the auto
setting only lights the display when the gauge is coupled to the material and receiving
a measurement.
The steps below outline how to toggle the options:
Backlight
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
LITE feature is being displayed.
3) Press the key to edit the light setting. The edit icon will be illuminated
and flashing.
4) Use the keys to toggle status on/off/auto.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
5) When the desired LITE setting is displayed, press the key to set the
status and edit the BRT (brightness) option.
6) Use the keys to scroll through the BRT (LO, MED, HI)
options.
7) When the desired BRT setting is displayed, press the key to set the
brightness and return to the measurement screen.
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8) Note: Pressing the key prior to pressing the key will abort to
the measurement screen without saving changes.
8.7 Beep
The PZX-7 DL also has a feature to use the internal beeper, most commonly used
with the alarm feature, for the key strokes on the keypad. When enabled, pressing
any of the keys on the keypad will sound the beeper.
The procedure to enable the keyboard beeper feature is outlined below:
Beeper
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
BEEPER feature is being displayed.
3) Press the key to edit the beeper setting. The edit icon will be
illuminated and flashing.
4) Use the keys to toggle the beeper on/off.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
5) When the desired BEEP setting is displayed, press the key to set the
status and return to the measurement screen.
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8.8 Probe Type
The PZX-7 DL can use three different probe/transducer styles for different application
requirements. The styles are; CONTACT, DELAY LINE, and plastics PLAS. The
corresponding option ‘must’ be selected to match the type of transducer connected to
the PZX-7 DL in order for the gauge to operate correctly.
The procedure to select the probe type is outlined below:
Probe
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
PROB feature is being displayed.
3) Press the key to edit the probe type. The edit icon will be illuminated
and flashing.
4) Use the keys to select the contact/delay line/plastics
option.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
5) When the desired PROB type is displayed, press the key to set the
type and return to the measurement screen.
Note: If the ‘contact’ option was selected, the diameter and frequency of the
contact style transducer must be selected in order to operate correctly.
6) Use the keys to select the diameter & frequency (.12 5,
.12 10, .25 5, .25 10, .37 5, .50 5, .50 10 inches).
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Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
7) When the desired PROB diameter is displayed, press the key to set
the diameter and return to the measurement screen.
8.9 Velocity (VX)
When the velocity setting (VX) is enabled, the PZX-7 DL will display the material
velocity as the primary measurement quantity instead of dimensional thickness. The
feature is generally used for basic “nodularity” testing, as velocity is a key part of
density for determining hardness. An example might be casting manufacturers
where the density/hardness will determine the strength of the material.
When this feature is enabled, the PZX-7 DL is operating in reverse to the standard
option of the gauge. Only the ‘one point’ calibration can be used with this feature
active, and a manual or auto zero is still required. The PZX-7 DL can be calibrated
by entering the known velocity or entering the know thickness of the material at a
given position on the test material. Refer to the ‘making measurements’ section on
page 26 for a complete explanation of the zero and one point calibration procedure.
The procedure to enable the velocity feature is outlined below:
Velocity Gauge
1) Press the key to access the menu items/features.
2) Use the keys to scroll through the items/features until the
VX feature is being displayed.
3) Press the key to edit the setting. The edit icon will be illuminated and
flashing.
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4) Use the
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving changes.
5) When the desired VX setting is displayed, press the key to set the
status and return to the measurement screen.
keys to select the on/off option.
8.10 Lock
The lock feature was built into the PZX-7 DL for the purpose of locking the operators
out of editing any of the gauge settings, for purposes of consistency between
operators. When the lock feature is enabled, the gauge calibration functionality
cannot be altered, as well as any of the individual features in the gauge. The only
keys that are always unlocked are the power and probe zero keys, as these must
remain unlocked for measurement functionality.
The procedure to enable/disable the lock feature is outlined below:
Lock
1) With the PZX-7 DL powered off, press and hold down the key while
powering the PZX-7 DL on . The lock icon will be illuminated on the
display.
2) To unlock the PZX-7 DL repeat step one, but hold down the key
while powering the PZX-7 DL on .
8.11 Factory Defaults
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The PZX-7 DL can be reset to factory defaults at any time to restore the original
gauge settings. This should only be used if the gauge is not functioning properly, or
perhaps multiple features have been enabled and a clean start is needed.
The procedure to reset the gauge is outlined below:
Factory Reset
1) With the PZX-7 DL powered off, press and hold down the and
keys while powering the PZX-7 DL on .
Note: Once the measurement screen is displayed the and can be
released.
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CHAPTER NINE
DATA STORAGE
9.1 Introduction
The PZX-7 DL is equipped with a basic and convenient sequential style data logger
that’s intuitive to operate. By ‘sequential’ meaning a single column of 250
measurements and a total of 40 individual files, for a total storage capacity of 10,000
measurements. These files can then be transferred to a PC using the USB-C to USB
type A cable included in the kit. When PZX-7 DL is connected to a PC, it will show
up in the list of drives as an external hard drive, or “thumb” drive. Open the external
gauge drive, and copy the files to and from the gauge and PC.
The file format is .csv (comma separated) and can be opened using any text editor,
spreadsheet editor, or Dakota’s proprietary PC software supplied with the gauges.
Only files with at least one measurement stored in the file will appear in the external
drive folder.
9.2 Opening a Data File
Open Data File
1) Press the key to access the data files and display the current file open.
2) Press the key to edit which file to open. The edit icon will be
illuminated and flashing.
3) Use the keys to scroll through the files.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without saving any changes.
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4) When the desired FILE is displayed, press the key to open the file and
return to the measurement screen.
Note: The FILE and LOC (location) will be displayed in lower left portion of the
measurement screen.
9.3 Storing a Measurement
Now that a file has been selected and opened, the PZX-7 DL is ready to store
measurements.
The following procedure outlines this process:
Storing Data
1) Use the keys to scroll to the desired location to store a
measurement.
2) Press the key to store a measurement and advance to the next
location (LOC).
3) Repeat steps 1 and 2 as needed.
Note: If an area exists where a measurement cannot be obtained successfully,
press the key to store OBST (obstruction) in the location. Pressing the
again will clear the location.
Note: If a measurement has been previously stored in a location, scrolling to
that location will display the measurement currently stored, and show MEM
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(memory) in the top right corner of the display. If the key is pressed
to store another measurement at that location, FULL will briefly be
displayed on the screen indicating a measurement has already been stored
at that location. Pressing the key will clear the previously stored
measurement from the location. Pressing the key will now store the
new measurement.
9.4 Clearing a File
If a file contains a large number of previously stored measurements, and has already
been downloaded, the file will need to be cleared of its measurements.
The following procedure outlines this process:
Clear File
1) Press the key to access the data files and display the current file open.
2) Press the key to edit which file will be cleared. The edit icon will be
illuminated and flashing.
3) Use the keys to scroll to the file that will be cleared.
4) When the desired FILE is being displayed, press the key to select the
file to be cleared.
5) Use the keys to scroll to CLR (clear).
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6) Press the key to display the confirmation screen. CLR? will be
displayed, as well as a flashing Yes/No option.
7) Press the key for YES, and the key for NO. The edit icon
will be illuminated and flashing.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without clearing the file.
8) Press the key to confirm Yes/No selection and return to the
measurement screen.
Note: If Yes was selected a BUSY message will briefly be displayed
confirming the file is being cleared.
9.5 Clear All Files
If a number of files in the PZX-7 DL contain old data, or data that has been previously
downloaded, clearing all the files might prove an efficient option.
The following procedure outlines this process:
Clear Files
1) Press the key to access the data files and display the current file open.
2) Use the keys to scroll to the CLR ALL option.
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3) Press the key to display the confirmation screen. CLR ALL is
displayed, as well as a flashing Yes/No option.
4) Press the key for YES, and the key for NO. The edit icon
will be illuminated and flashing.
Note: Pressing the key prior to pressing the key will abort to the
measurement screen without clearing the files.
5) Press the key to confirm Yes/No selection and return to the
measurement screen.
Note: If Yes was selected a BUSY message will briefly be displayed
confirming the files are being cleared.
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CHAPTER TEN
DATA TRANSFER & POWER OPTIONS
10.1 Connectivity
The PZX-7 DL is connected to a PC with a USB-C to USB Type A cable, supplied
with the kit (part# N-003-0330). The gauge has a file system and the PC will
recognize it as an external hard disk, or thumb drive. It functions very similar to a cell
phone or camera. Opening the external disk folder will display only the files that
currently have data stored in them, and while the other files are physically in the
directory, they are hidden until they contain data. The PZX-7 DL has a maximum of
40 total files with 250 sequential readings per file.
10.2 Opening a File
The data files are stored as a .CVS (comma separated) text file, which is a very basic
generic text file structure. It can be conveniently opened using any standard text
editor, spreadsheet or database program. The data can easily be copied, moved or
imported into reports created by a variety of software packages.
With the gauge turned on and connected to your PC a drive called “ultrasonics” will
appear in your list of devices:
Open the external drive to view the files.
10.3 Copying/Opening Files
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Now that the files have been located and are accessible, they can either be opened
from the PZX-7 DL’s memory, or copied to another location/folder on your PC. To
accomplish this, simply ‘drag and drop’ files in a new folder on your PC, or on your
desktop.
If you have a specific software package associated with .CSV files, like a
spreadsheet editor, they can automatically be opened by ‘double clicking’ one of the
active files in the folder. Alternatively, you can specify what software package you’d
like them opened with by ‘right clicking’ on a specific file and using the ‘open with’
option in the menu.
Spreadsheet Text Editor
10.4 Line Power
The PZX-7 DL can be powered using the standard USB-C to USB-A data cable (N-
003-0330), by connecting directly to a USB port on your computer, or using a
standard cell phone power adapter directly to an outlet. This is a convenient way to
power the gauge for specific bench top applications in a factory line environment.
Note: If USB is being displayed on the display, the PZX-7 DL is currently in
download/transfer mode. This can be bypassed by pressing any key to abort the
transfer mode, and return to actively measuring and using line power.
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APPENDIX A VELOCITY TABLE
Material sound velocity
in/us
Aluminum 0.2510 6375
Beryllium 0.5080 12903
Brass 0.1730 4394
Bronze 0.1390 3531
Cadmium 0.1090 2769
Columbium 0.1940 4928
Copper 0.1830 4648
Glass (plate) 0.2270 5766
Glycerine 0.0760 1930
Gold 0.1280 3251
Inconel 0.2290 5817
Iron 0.2320 5893
Cast Iron 0.1800 (approx) 4572
Lead 0.0850 2159
sound velocity
m/s
Magnesium 0.2300 5842
Mercury 0.0570 1448
Molybdenum 0.2460 6248
Monel 0.2110 5359
Nickel 0.2220 5639
Nylon 0.1060 (approx) 2692
Platinum 0.1560 3962
Plexiglas 0.1060 2692
Polystyrene 0.0920 2337
PVC 0.0940 2388
Quartz glass 0.2260 5740
Rubber vulcanized 0.0910 2311
Silver 0.1420 3607
Steel (1020) 0.2320 5893
Steel (4340) 0.2330 5918
Steel Stainless" 0.2230 5664
Teflon 0.0540 1372
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Tin 0.1310 3327
Titanium 0.2400 6096
Tungsten 0.2040 5182
Uranium 0.1330 3378
Water 0.0580 1473
Zinc 0.1660 4216
Zirconium 0.1830 4648
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APPENDIX BAPPLICATION NOTES
Measuring hot surfaces
The velocity of sound through a substance is dependent on its temperature. As
materials heat up, the velocity of sound through them decreases. In most
applications with surface temperatures less than about 200F (100C), no special
procedures must be observed. At temperatures above this point, the change in
sound velocity of the material being measured starts to have a noticeable effect upon
ultrasonic measurement.
At such elevated temperatures, it is recommended that the user perform calibration
on a sample piece of known thickness, which is at or near the temperature of the
material to be measured. This will allow the PZX-7 DL to correctly calculate the
velocity of sound through the hot material.
Expansion and contraction of the transducer based on temperature, and a varying
temperature gradient, will also affect the measurement in a pulse-echo (P-E)
measurement mode. It is recommended that a “transducer zero” be performed often
to account for the delay line changing length and adversely affecting the accuracy of
the measurements.
When performing measurements on hot surfaces, it may also be necessary to use a
specially constructed high-temperature transducer. These transducers are built using
materials which can withstand high temperatures. Even so, it is recommended that
the probe be left in contact with the surface for as short a time as needed
(intermittent contact) to acquire a stable measurement.
Measuring laminated materials
Laminated materials are unique in that their density (and therefore sound-velocity)
may vary considerably from one piece to another. Some laminated materials may
even exhibit noticeable changes in sound-velocity across a single surface. The only
way to reliably measure such materials is by performing a calibration procedure on a
sample piece of known thickness. Ideally, this sample material should be a part of
the same piece being measured, or at least from the same lamination batch. By
calibrating to each test piece individually, the effects of variation of sound-velocity will
be minimized. If the variation is relatively close, averaging the sound velocities to
minimize error is another option.
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An additional important consideration when measuring laminates is that many
included air gaps or pockets which will cause an early reflection of the ultrasound
beam. This effect will be noticed as a sudden decrease in thickness in an otherwise
regular surface. While this may impede accurate measurement of total material
thickness, it does provide the user with positive indication of air gaps in the laminate.
Measuring through paint & coatings
Measuring through paints and coatings are also unique, in that the velocity of the
paint/coating will be significantly different from the actual material being measured. A
perfect example of this would be a mild steel pipe with .025” of coating on the
surface. Where the velocity of the steel pipe is .2330 in/sec, and the velocity of the
paint is .0850 in/sec. If the user is calibrated for mild steel pipe and measures
through both materials, the actual coating thickness will appear to be approximately 3
times thicker than it actually is, as a result of the differences in velocity. This error
can be eliminated by using a special echo-echo (E-E) mode to perform
measurements for applications such as these. In echo-echo mode, the paint/coating
thickness will be eliminated entirely and only the steel or base metal measured.
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WARRANTY INFORMATION
Warranty Statement
Dakota Ultrasonics warrants the PZX-7 DL against defects in materials and
workmanship for a period of two years from receipt by the end user. Additionally,
Dakota Ultrasonics warrants transducers and accessories against such defects for a
period of 90 days from receipt by the end user. If Dakota Ultrasonics receives notice
of such defects during the warranty period, Dakota Ultrasonics will either, at its
option, repair or replace products that prove to be defective.
Should Dakota Ultrasonics be unable to repair or replace the product within a
reasonable amount of time, the customer's alternative exclusive remedy shall be
refund of the purchase price upon return of the product.
Exclusions
The above warranty shall not apply to defects resulting from: improper or
inadequate maintenance by the customer; unauthorized modification or misuse; or
operation outside the environmental specifications for the product.
Dakota Ultrasonics makes no other warranty, either express or implied, with
respect to this product. Dakota Ultrasonics specifically disclaims any implied
warranties of merchantability or fitness for a particular purpose. Some states or
provinces do not allow limitations on the duration of an implied warranty, so the
above limitation or exclusion may not apply to you. However, any implied warranty of
merchantability or fitness is limited to the five-year duration of this written warranty.
This warranty gives you specific legal rights, and you may also have other rights
which may vary from state to state or province to province.
Obtaining Service During Warranty Period
If your hardware should fail during the warranty period, contact Dakota
Ultrasonics and arrange for servicing of the product. Retain proof of purchase in
order to obtain warranty service.
For products that require servicing, Dakota Ultrasonics may use one of the
following methods:
- Repair the product
- Replace the product with a re-manufactured unit
- Replace the product with a product of equal or greater performance
- Refund the purchase price.
After the Warranty Period
If your hardware should fail after the warranty period, contact Dakota Ultrasonics
for details of the services available, and to arrange for non-warranty service.
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