Dakota CMX DL User Manual

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OPERATION MANUAL

DAKOTA ULTRASONICS

DDL

CCMMX

Material & Coating Thickness Gauge

P/N P-171-0002 Rev 1.30, April 2008

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CHAPTER ONE INTRODUCTION.......................................................................1

CHAPTER TWO QUICK STARTUP GUIDE........................................................2

CHAPTER THREE KEYBOA RD, MENU, & CONNECTOR REFERENCE.......22

CHAPTER FOUR PRINCIPALS OF ULTRASONIC ME ASUREMENT .............31

CHAPTER FIVE SELECTING THE MEASUREMENT MODE..........................36

CHAPTER SIX MAKING MEASUREMENTS.....................................................39

CHAPTER SEVEN USING THE DIGITS & B-SCAN DISPLAYS ......................55

CHAPTER EIGHT THRU PAINT MEASUREMENT TECHNIQUE....................66

CHAPTER NINE PULSE-ECHO COATING & COATING TECHNIQUES.........67

CHAPTER TEN ADDITIONAL FEATURES OF THE CMXDL.............................82

CHAPTER ELEVEN DATA STORAGE – SETUP, EDIT, & VIEW FILES.........87

CHAPTER TWELVE SETUPS – CREATE, STORE, EDIT, & RECALL..........112

CHAPTER THIRTEEN USI NG THE UTILITY SOFTWARE.............................122

APPENDIX A - VELOCITY TABLE ...................................................................124

APPENDIX A - SETUP LIBRARY.....................................................................126

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CHAPTER ONE INTRODUCTION

The Dakota Ultrasonics model CMXDL is an ultrasonic thickness gauge that measures with extreme versatility. It has the ability to measure simultaneously measure coatings and material thicknesses while maintaining the ability to locate pits, flaws and defects in the material. Based on the same operating principles as SONAR, the CMXDL is capable of measuring the thickness of various materials with accuracy as high as ± 0.001 inches, or ± 0.01 millimeters. The principle advantage of

ultrasonic measurement over traditional methods is that ultrasonic measurements can be performed with access to only one side of the material being measured.

Dakota Ultrasonics maintains a customer support resource in order to assist users with questions or difficulties not covered in this manual. Customer support may be reached at any of the following:

• Dakota Ultrasonics Corporation, 1500 Green Hills Road, #107 Scotts Valley, CA 95066 USA

• Telephone: (831) 431- 9722

• Facsimile: (831) 431-9723

• http://www.dakotaultrasonics.com

1.1 Disclaimer

Inherent in ultrasonic thickness measurement is the possibility that the instrument will use the second rather than the first echo from the back surface of the material being measured. This may result in a thickness reading that is TWICE what it should be. Responsibility for proper use of the instrument and recognition of this phenomenon rest solely with the user of the instrument. Other errors may occur from measuring coated materials where the coating is insufficiently bonded to the material surface. Irregular and inaccurate readings may result. Again, the user is responsible for proper use and interpretation of the measurements acquired.

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CHAPTER TWO QUICK STARTUP GUIDE

Turn the CMXDL on and off using the switch located on the bottom right corner of the keypad. When CMXDL is initially turned on, a flash logo and blinking lights will be displayed, followed by attempting to identify the transducer(probe) currently plugged into the gauge. The CMXDL is equipped with an “Auto Probe Recognition” feature that attempts to identify special transducers with this built in feature. If the CMXDL doesn’t find a transducer equipped with this feature, the user will be advanced to a list of transducers requiring the u ser to select a specific transducer type. The following sections outline each scenario. Note: This section is primarily written as a basic startup guide only.

2.1 CMXDL Overview

In order to understand how to operate the CMXDL, it’s best to start off with an understanding of what it is we’re looking at exactly. The CMXDL has a lot of great features and tools that will prove to be a huge benefit for the variety of applications you’re constantly facing on a continual basis. Let’s have a brief look at the screens you’ll be looking at most often:

A. Repeatability/Stability Indicator – This indicator should be commonly used

in conjunction with the digital thickness values displayed. When all the vertical bars are fully illuminated and the last digit on the digital thickness value is stable, the CMXDL is reliably measuring the same value 3 to 200 times per second, depending on which measurement mode and features are enabled.

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B. Battery Icon – Indicates the amount of battery life the CMXDL has remaining. C. Velocity – The material velocity value the CMXDL is currently using or

calibrated for. Displayed in both English or Metric units, depending on the what units the gauge is set for.

D. Feature Status Bar – Indicates the features currently enabled and in use in

the following order:

• Measurement Mode

• Differential Mode

• High Speed Scan Mode

• Alarm Mode

• Gain Setting

E. Digital Material Thickness Value – Extra large font size for viewing ease. F. Scan Bar – Another view of material thickness in a deflection style horizontal

bar. This is a visual tool that would enable the user the ability to see thickness changes during high speed scans from flaws and pits.

G. Units – The current measurement units being used (English, Metric). H. Digital Material Thickness Value – Smaller font size when the B-Scan

display view is enabled.

I. Coating Thickness Value – Displays the actual thickness of any coating

adhered to a metallic material surface (PECT Mode), or a coating adhered to a non-metallic surface (CT Mode).

J. Minimum Material Thickness – Part of the Al arm feature. Displays the

minimum thickness value found during a scan.

K. Maximum Material Thickness – Part of the Alarm feature. Displays the

maximum thickness value found during a scan.

L. B-Scan Display – Cross section view of the material. Provides the user with

graphical view of the opposite/blind surface (i.e. inside pipe wall surface), to give the user some idea of the condition, or integrity of the material being tested.

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2.2 Auto Probe Recognition

When the CMXDL is initially powered up, the gauge will automatically check to see if the transducer plugged into the gauge can be recognized. The steps that follow assume the CMXDL recognized the probe type:

Probe Automatically Recognized

1) Press the OK key once to use the identified probe, or ESC to display a list of

optional transducers. Note: if the CMXDL recognizes a specific transducer,

the user should always select OK to use the identified probe. The only time an alternative probe should be selected from a list is if the user switched probes following initial power up and recognition.

2) Assuming the CMXDL recognized the probe and the OK key was pressed, the CMXDL will advance to a Zero Probe menu. If the transducer was identified as a special transducer capable of measuring coating thickness, a menu will be displayed allowing the user the ability to toggle the coating thickness display on/off as follows:

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3) Press the UP and DOWN arrow keys to toggle the coating option on/off.

4) Wipe all couplant from the transducer face and advance to the Probe Zero

& Calibration section outlined below.

2.3 Selecting the Transducer Type

If the CMXDL does not identify a specific transducer type on initial power up, the user will be required to select a type from a predefined list of types by diameter and frequency. By selectin g a transducer type from a predefined list, the CMXDL can recall specific properties about the transducer. Note: Once the transducer has been

selected, the CMXDL will store and recall this transducer type every time the CMXDL is powered on/off. The type will only change if the user physically selects another transducer type from the list, or selects a previously saved setup. However, the

CMXDL will continue to take you through these steps each time the gauge is powered

up. You’ll notice that the probe type previously selected will be highlighted every time the probe type screen is displayed. Use the following steps to select your transducer type:

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Selecting the Transducer Type

1) Press the OK or ESC keys to display the factory list of transducer types (by diameter and frequency).

2) Press the UP and DOWN arrow keys to scroll through the transducer list until the appropriate type is highlighted.

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3) Press the ENTER key to select the transducer type and display overwrite existing probe screen.

4) Press the OK key to overwrite the existing probe type with the newly selected probe type. The zero probe screen will be displayed. Proceed to

the zero probe section that follows.

2.4 Probe Zero & Calibration

The next steps are to perform a probe zero and calibrate the CMXDL to the material and transducer being used. If the sound velocity is unknown, the CMXDL can be calibrated to a known thickness sample. This demo will briefly explain both of these techniques.

The CMXDL is equipped with two zero options:

1) Off Block Zero (Automatic Probe Zero) – When this feature is enabled the

CMXDL will do an electronic zero automatically, eliminating the need for a zero

disk or block.

2) On Block Zero (Manual Probe Zero) – When this feature is enabled the transducer must be placed on the probe zero disk (battery cover located on the

top of the unit.

Note: Transducers of the same type will have very slight mechanical and electrical variations. If it’s discovered that the linearity is off following an initial auto probe zero

and extreme accuracy is required, a manual zero should be performed followed by an auto zero. This will adjust and eliminate any error. This is only required if it’s discovered the transducer is non-linear following an initial auto probe zero.

The procedures are outl ined as follows:

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Performing an Auto Probe Zero (Off Block)

Coating Probe Identified Coating Probe Not Identified

1) Be sure all couplant has been removed from the face of the transducer.

2) Press the OK key to perform the automatic probe zero, or ESC key to cancel the zero operation.

Coating Probe Identified Coating Probe Not Identified

3) The screens illustrated above will be briefly displayed followed by the main measurement screen. The CMXDL is ready to be calibrated.

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Performing a Manual Probe Zero (On Block)

Note: When the zero probe option is set to manual, the probe zero disk

(battery cap) located on the top of the gauge, will be used as a zero standard and the warning screen illustrated above will be displayed.

1) Press the OK or ESC keys to enter the main measurement screen and begin the manual zero process.

2) Apply a drop of couplant on the transducer and place the transducer in steady contact with the probe zero disk, and obtain a steady reading.

3) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the PRB menu is highlighted and displaying the submenu items.

4) Press the UP and DOWN arrow keys to scroll through the sub menu items until ZERO PROBE is highlighted.

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Coating Probe Identified Coating Probe Not Identified

5) Press the ENTER key to display the confirmation screen.

6) If a coating transducer was identified use the UP and DOWN arrow keys to toggle coating on/off.

7) Press the OK key to complete the probe zero function, or ESC key to cancel the probe zero function.

8) Remove the transducer from the probe zero disk, and proceed to the calibration section.

Note: The value that is displayed will change depending on the current velocity setting in the CMXDL. Disregard the number that is displayed. It is not important. What is important is accurately performing the steps outlined above to insure reliability of the probe zero calculation.

One Point Material Calibration

For the purposes of this quick start section, we’ll only be covering the most common one point calibration option to determine the sound velocity of the test material. It would be very handy to carry a set of mechanical calipers to use in conjunction with the CMXDL for calibration in the field:

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Using a Known Thickness

Note: Be sure that the probe zero procedure 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. Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

3) Use the UP and DOWN arrow keys to scroll through the sub menu items until MATL 1PT is highlighted.

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4) Press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the known thickness value is correctly displayed.

8) Press the OK key to calculate the velocity and return to the menu screen, or ESC to cancel the one point calibration.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

Note: CHECK YOUR CALIBRATION! Place the transducer back on the calibration point. The thickness reading should now match the known

thickness. If the thickness is not correct, repeat the steps above.

2.5 Zero Coating

In order to account for very slight electronic differences in transducers of the same type, frequency, and diameter, the CMXDL has been equipped with a “zero coating” feature. This enables the CMXDL to obtain very accurate readings on coatings, eliminating potential errors incurred from slight differences in the manufacturing processes. The procedure is outlined below:

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Performing a Coating Zero

1) Press the MULTI MODE key once to activate the measurement mode options.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until Coating Only (CT) mode is highlighted.

3) Press the ENTER key to select the measurement mode and return to the measurement screen.

4) Apply a drop of couplant on the transducer and place the transducer in steady contact with the probe zero disk (battery cover) and obtain a steady reading.

Note: The coating measurement displayed will potentially be a value greater or less than 0.

5) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the PRB menu is highlighted and displaying the submenu items.

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6) Use the UP and DOWN arrow keys to scroll through the sub menu items until ZERO COATING is highlighted.

7) Press the ENTER key to display the confirmation screen.

8) Press the OK key to zero the coating and return to the PRB menu, or ESC to cancel the coating zero process.

9) Press the MULTI MODE key once to activate the measurement mode options.

10) Use the UP and DOWN arrow keys to scroll through the sub menu items until Coating On (PECT) is highlighted.

11) Press the ENTER key to select the measurement mode and return to the measurement screen, and begin taking readings.

2.6 Coating Calibration

The CMXDL has been preset to a default coating velocity of 0.0850 in/µsec (2159 m/sec). This will be very close to the most common coating material velocities used in the field. If the velocity of the coating is known, and different than the above default setting, the user can simply enter the coating velocity into the CMXDL. However, if the velocity is unknown, the CMXDL can also be calibrated to a specific coating sample/type using the 1pt calibration option in PECT (pulse-echo coating) mode, or a two point calibration is CT (coating only) mode. For the purpose of this

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quick start section only the 1pt option PECT (pulse-echo coating) mode will be covered. Refer to the calibration section of the manual for a complete explanation on the coating calibration options. The following steps below outline the necessary steps to either set the velocity of the coating, or perform a one point calibration to calculate the coating velocity:

Known Coating Velocity

If the coating velocity is known, the user may wish to simply enter the velocity number into the CMXDL, rather than have the CMXDL calculate the velocity value using a known thickness on a coating sample. The steps for entering the velocity are outlined below:

Using a Known Coating Velocity

12) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

13) Use the UP and DOWN arrow key s to scroll through the sub menu items until COATING VEL is highlighted.

14) Press the ENTER key to display the Digits Edit Box.

15) Press the UP and DOWN arrow keys to scroll the highlighted value.

16) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

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17) Repeat steps 4 & 5 until the velocity number is correctly displayed.

18) Press the OK key to set the coating velocity and return to the menu screen, or ESC to cancel entering the coating velocity.

19) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

Known Coating Thickness

When the exact velocity of a coating is unknown, the user has the option of performing a one point calibration on a sample of the coating with a known thickness to determine the sound velocity. It would be very handy to carry a set of mechanical calipers to use in conjunction with the CMXDL for calibration in the field:

Using a Coating Sample to Calibrate

1) Physically measure a location on a coating sample using a set of calipers or a digital micrometer.

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Important Note: In PECT (pulse-echo coating) mode, the coating sample must be coupled to metal in order to calibrate successfully. Simply place a drop of

couplant on a piece of metal, lay the coating sample over the couplant on the metal and proceed to step 2.

2) Apply a drop of couplant on the transducer and place the transducer in steady contact with the coating (on metal) 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. Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted

and displaying the submenu items.

3) Use the UP and DOWN arrow keys to scroll through the sub menu items until COATING 1PT is highlighted.

4) Press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the known thickness value is correctly displayed.

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8) Press the OK key to calculate the coating velocity and return to the menu screen, or ESC to cancel the one point calibration.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

Note: CHECK YOUR CALIBRATION! Place the transducer back on the calibration point. The coating thickness reading should now match the known coating thickness sample. If the thickness is not correct, repeat the steps above.

2.7 Measure

The CMXDL is now ready to measure. There are two different measurement view options, each with a specific purpose – Digits & B-Scan. The steps below outline how to toggle between the different view mode options:

Selecting the Measurement View Option

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the DISP menu is highlighted and displaying the submenu items.

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2) Use the UP and DOWN arrow keys to scroll through the sub menu items

until VIEW is highlighted.

3) Use the LEFT and RIGHT arrow keys to scroll the view options.

4) Once the view is displayed, press the MEAS key to return to measurement

mode.

DIGITS: Displays the digital thickness value using a large font size. This view is useful when the CMXDL is being used as a basic thickness gauge.

BSCAN: The Time Based B-Scan provides the user with a cross sectional view of the material being tested. This mode is useful when there is concern regarding the profile of the blind surface. This can also be a useful view when scanning for pits and flaws.

Once the view has been selected according to the application requirements, the B- START and B-DEPTH of the screen will potentially need to be adjusted if the view has been set to BSCAN. Use the following steps to adjust these as follows:

Note: The B-Start and B-Depth are also used to adjust the parameters of Scan Bar.

Adjusting B- START & B-DEPTH

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1) Press the MENU key once to activate the menu items tab. Press the MENU

key multiple times to tab right and the ESC key multiple times to tab left until the DISP menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items

until B-START or B-DEPTH is highlighted.

3) Use the LEFT or RIGHT arrow keys to increase/decrease the start or depth

values in coarse increments/decrements.

4) Repeat steps 2 & 3 until the range is correctly being displayed.

Alternatively, the B-START and B-DEPTH values can be changed using the Digit Edit Box as follows:

1) Use the UP and DOWN arrow keys to scroll through the sub menu items

until B-START or B-DEPTH is highlighted.

2) Press the ENTER key to display the digits edit box.

3) Press the UP and DOWN arrow keys to scroll the highlighted value.

4) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

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5) Repeat steps 3 & 4 until the B-START or B-DEPTH value is correctly displayed.

6) Press the OK key to set the B-START or B-DEPTH value and return to the DISP menu , or ESC to cancel entering the B-START or B-DEPTH value. Note: the adjusted value will appear next to the B-START or B-DEPTH menu labels.

7) Finally, press the MEAS key to return to the measurement screen and begin

taking readings.

DIGITS B-SCAN

In the upper left corner of each of the display photos above, is the repeatability indicator. The repeatability indicator is represented by five vertical bars and represents how repeatable the measurements are. In regular measurement mode, the CMXDL makes 8 measurements a second. In scan mode, the CMXDL makes 200 measurements a second. If the coating mode option is activated, the CMXDL makes 3 measurements a second in regular measurement mode and 65 measurements a second in scan mode. When the CMXDL is idle, only the left vertical bar will be displayed. However, when the CMXDL is making a measurement, four or five of the bars should be displayed on the repeatability indicator. If f ewer than four bars are showing, the CMXDL is having difficulty achieving a stable measurement and the thickness value displayed is potentially unstable.

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CHAPTER THREE KEYBOARD, MENU, & CONNECTOR REFERENCE

3.1 Menu Key (Operation & Sub Menus)

The Menu key activates the primary menu structure containing 8 menu tab groups. These tab groups then contain sub menu items, or functions. The sub menu items have been organized in tab groups according to how closely they are related to the individual tab group names. L et’s first get familiar with how to move around in these tabs before continuing on to the sub menu functions. This procedure is outlined below:

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Activating and Getting Around in the Menu Items

1) Press the MENU key once to activate the menu items tab. Pr ess the MENU

key multiple times to tab right, and the ESC key multiple times to tab left until the desired tab group is highlighted and displaying the submenu items.

The tab groups are illustrated above (A).

Now that you’re familiar with activating and moving amongst the tab groups, let’s have a look at how to move around in the sub menu items as follows:

Getting Around in the Sub Menu Items

1) Use the UP and DOWN arrow keys to scroll through the sub menu items until the desired function is highlighted. The sub menu items are illustrated

in the diagram above (B).

2) Depending on which function is highlighted, use the LEFT, RIGHT, and Enter keys to scroll the options or activate the Digit Edit and List Box options.

The sections to follow will provide the user with an explanation of the sub menu functions:

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3.2 Probe – Menu

ZERO PROBE: The CMXDL is zeroed in much the same way that a mechanical

micrometer is zeroed. If the CMXDL is not zeroed correctly, all of the measurements made using the CMXDL may be in error by some fixed value. The CMXDL is equipped with an optional automatic or manual zero feature. Refer to the section on page 43, for an explanation of this important procedure.

ZERO COATING: In order to account for very slight electronic differences in transducers of the same type, frequency, and diameter, the CMXDL has been

equipped with a “zero coating” feature. This enables the CMXDL to obtain very accurate readings on coatings, eliminating potential errors incurred from slight differences in the manufacturing processes. Refer to the section on page 43, for a detailed explanation.

TYPE: Enables the user to select the type of transducer being used from a chart of transducer types. This provides increased linearity between transducers. Refer to page 39 for a further explanation.

3.3 CAL – Menu

MAT: Select the material velocity from a chart of basic material types when a known

sample thickness, or material velocity cannot be obtained. Refer to page 52 for further info.

MATL 1PT: Performs a single point calibration. This option allows the user to automatically calculate the velocity by entering a known sample thickness. Refer to page 49 for further info.

MATL 2PT: Performs a two-point calibration. This option allows the user to automatically calculate the velocity by entering a second known sample thickness. Refer to page 51 for further info.

VELOCITY: Function to calibrate the CMXDL by setting the velocity to a known material velocity. Refer to page 46 for further info.

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COATING 1PT: Performs a single point coating calibrat ion. This option allows the user to automatically calculate the velocity by measuring a known coating sample thickness. Refer to page 77 for further info.

COATING 2PT: Performs a two-point coating calibration. This option allows the user to automatically calculate the velocity by entering a second known coating

sample thickness. Refer to page 77 for further info. COATING VEL: F unction to calibrate the CMXDL to a specific coating material type by entering a coating velocity. Refer to page 15 or page 71 for further info.

3.4 DISP (display) – Menu

VIEW: Selectable BSCAN (cross section), and DIGITS (large digits) views. Refer to

page 56 for further info. B-START: Provides the user the ability to change the start position of the B-SCAN

view. Refer to page 60 for further info. B-DEPTH: Provides the user the ability to change the overall depth of the viewable

measurement area. It functions a lot like a zoom on a camera. Refer to page 62 for further info.

UNITS: Toggle between English or Metric units. The readout will change from inches to millimeters.

BACKLIGHT: Selectable OFF, ON, AUTO, or INVERT backlight option. CONTRAST: Adjustable display contrast for variable light conditions.

3.5 TUNE – Menu

MEASURE MODE: Toggles a variety of unique measurement modes for different

application requirements. Refer to page 32 for further info. GAIN: A 5 position gain switch in 2 db increments from 40 to 50 dB. Increase for

better penetration or punch, and decrease to eliminate unwanted noise or better resolution. Refer to page 64 for further info.

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3.6 SETUP – Menu

OPEN: Displays a list of factory and user defined setups currently stored in memory.

These setups can be recalled and used at any time. Refer to page 112 for further info.

SAVE: Provides the user with the ability to save a custom setup that has been modified or created by the user. Refer to page 114 for further info.

DELETE: Provides the user with the ability to delete specific setups previously save in memory. Refer to page 118 for further info. DEFAULT SETUP : Loads a basic default setup. Use only as a last resort when the setups in the CMXDL have been corrupted and a computer is not accessible. Refer to

page 119 for further info. LANGUAGE: Provides the user the ability to select different languages for the

CMXDL. Refer to page 121 for further info.

3.7 DATA – Menu

NEW: Allows the user the ability to creat e a new alpha numeric grid, or sequential

log file with auto identifiers. Equipped with custom parameters, rows, and columns depending on the users application reporting requirements. Refer to page 88 for further info.

EDIT: Giv es the user the ability to change parameters of grid or sequential file previously saved. Note: Pre-defined coordinates cannot be changed once they have

been created. Refer to page 105 for further info. OPEN: This function provides the user with the ability to recall grids or sequential log

files that currently exist in memory, from a list of grids. Refer to page 108 for further info.

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CLOSE: Provides the user the ability to close a currently opened grid or sequential log file. Refer to page 110 for further info.

DELETE ONE FILE: This function provides the user with the ability to delete one individual grid or sequential log file from a list of multiple grids/files previously saved in memory. Refer to page 103 for further info.

DELETE ALL DATA : This function provides the user with the ability to delete all files currently stored in memory. Refer to page 104 for further info.

3.8 UTIL (utilities) – Menu

SCAN MODE: This function enables a hi speed scan mode that increases the

overall sample rate from 65 to 200 measurements per second, depending on the current measurement mode used. Refer to page 82 for further info.

ALARM: Toggles alarm mode on , off, or audible. Refer to page 83 for further info. ALARM HIGH: Gives the user the ability to set the HI limit parameter. If the

measurement exceeds this value, a red light will illuminate and sound the internal beeper. Refer to page 83 for further info.

ALARM LOW : Gives the user the ability to set the LO limit parameter. If the measurement falls below this value, a red light will illuminate and sound the internal beeper. Refer to page 83 for further info.

DIFFERENTIAL: Gives the user the ability to set a nominal value and the CMXDL will display +/- the difference from the nominal value entered. Refer to page 85 for further info.

3.9 XFER (transfer) – Menu

BACKUP SETUPS : Enables the user the ability to backup the setups currently stored in the CMXDL to a PC via RS232 port. Refer the help section of the CMX DakView software for a complete electronic manual.

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RESTORE SETUPS : Enables the user the ability to restore the setups currently saved on a PC to an CMXDL via RS232 port. Refer the help section of the CMXDL

DakView software for a complete electronic manual. BACKUP DATA : Enables the user the ability to backup grids or sequential log files

currently stored in the CMXDL to a PC via RS232 port. Refer the help section of the

CMX RESTORE DATA : Enables the user the ability to restore grids or sequential log files

currently saved on a PC to an CMXDL via RS232 port. Refer the help section of the

CMXDL DakView software for a complete electronic manual. ABOUT: Provides the user with Dakota Ultrasonics con tact information and the

CMXDL software version. Refer the Dakota Ultrasonics web site for information on

the latest firmware versions available for download.

DakView software for a complete electronic manual.

3.10 CLR (clear) Key

The primary functions of the CLR key, is to clear a measurement from a grid or sequential log files cell location or set obstruct, and backspace in an Alpha Edit Box. If a user has already saved a measurement and B-Scan to a cell location, use this key to clear the measurement at any time.

3.11 MEAS (measurement mode) Key

The MEAS key puts the CMXDL into it’s primary mode of operation. In this mode, the user has a complete view of the LCD.

3.12 OK Key

The primary function of the OK key is confirmation of a change or selection. If the CMXDL is displaying a grid log, the OK key toggles an advance to row number option.

3.13 ESC Key

The ESC key is used in the MENU, MEAS, and EDIT functions as a back or escape function. If the CMX

display options: Digits and B-Scan views.

DL+

is displaying a grid or sequential log, the OK key toggles the

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3.14 Arrow Keys

The Arrow Keys are used to navigate through the menus, increase/decrease values, and toggle specific function keys.

3.15 ENTER key

The ENTER key is used in the overall menu selection process, to activate list and edit boxes, display and save measurements to grid or sequential files locations. Use this key to open your log files while making measurements.

3.16 MULTI MODE Key

The MULTI MODE key opens a measurement mode screen listing all the modes that are available to the transducer specifically selected. The modes can be all or a combination of the entire set of modes the CMXDL offers, depending on which transducer is being used as follows: Coating Off (P-E), Coating On (PECT), Temp

Comp (PETP), Thru-Coat (E-E), Thru Coat Verify (E-EV), and Coating Only (CT).

3.17 ON/OFF Key

The ON/OFF key simply powers the unit either ON or OFF. Note: Unit will automatically power off when idle for 5 minutes. All current settings are automatically

saved prior to powering off.

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3.18 Top & Bottom End Caps

The top & bottom end panels are where all connections are made to the CMXDL. The diagram above shows the layout and description of the connectors:

Transducer Connectors

Refer to Diagram: The transducer connectors, and battery cover/probe zero disk are located on the CMXDL’s top end cap. The transducer connectors are of type Lemo “00”. Note: There is no polarity associated with connecting the transducer to the

CMXDL.

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. Simply remove the cover

when replacing the batteries (3 AA cells). When performing a manual probe zero function, simply place the transducer on disk making firm cont act. Important: Be

sure to follow the polarity labels located on the back label of the CMXDL. Note: Rechargeable batteries can be used, however they must be recharged outside of the unit in a stand alone battery charger.

RS-232 Connector Refer to Diagram: The RS-232 connector, located on the bottom end cap, is a 2 pin

female Lemo connector. It is designed to connect directly from the CMXDL to a standard AT serial port on a PC. The cable supplied with the CMXDL is a Lemo to 9 pin serial cable. Note: This connector is also used to upgrade the CMXDL with the latest version of firmware.

USB Serial to USB Converter Cable

A converter cable can be attached to the 9 pin serial cable in needed (part no. N -402-

0510).

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CHAPTER FOUR PRINCIPALS OF ULTRASONIC MEASUREMENT

4.1 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.

4.2 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 th ickness 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.

4.3 Range of measurement and accuracy

The overall measurement capabilities, based on the wide variety of materials, is determined by the consistency of the material being measured

The range of thickness that can be measured ultrasonically depends on the material as well as the technique being used and the type of transducer. Thickness measurements can be made from a minimum of 0.010 inch to 9.999” in steel. However, the maximum attainable thickness is much less for more attenuative materials (materials that absorb sound).

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%.

4.4 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

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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.

4.5 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 0°F to 180°F.

High temperature measurements

Special transducers and couplants are available for temperatures above 180°F up to 650°F with intermittent contact. It is necessary to cool the transducer, by submerging the transducer in water between readings, when measuring high temperatures.

Modes and temperature errors

In addition to errors caused by velocity changing with temperature, some modes (measurement techniques) are affected more than others. For example, dual element pulse-echo mode has larger errors due to changes in the temperature of the delay line. However, multi-echo techniques offer temperature compensation help to minimize these errors.

4.6 Measurement Modes

In this section we will discuss the different measurements modes the CMXDL is capable of operating in, the transducers required, and the reasons for using specific modes:

Pulse-Echo Mode (Flaw & Pit detection) – Coating Off (P-E)

Pulse-echo mode measures from the initial pulse (sometimes referred to as an artificial zero) to the first echo (reflection). In this mode, either an automatic or manual zero can be performed depending on the zero probe function setting. If the manual mode has been selected, the transducer is placed on a reference disk, located on top of the CMXDL, and a key is pressed to establish a zero point for the particular transducer. If the Auto Zero feature is enabled, a simple key press will perform an electronic zero to establish the same zero point.

In this mode errors result from surface coatings and temperature variations. Since pulse-echo only requires one reflection, it is the most sensitive mode for

measuring weak reflections (flaws) typically found when measuring heavily corroded metals.

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V-Path Correction

Dual element delay line transducers have two piezoelectric elements mounted at an angle on one end of the delay line. One element is used for transmitting sound, while the other element only receives sound. The two elements and their delay lines are packaged in a single housing but acoustically isolated from each other with a sound barrier. This allows the transducer the ability to achieve very high sensitivity for detecting small defects. Also, the surface of the test material does not have to be as flat in order to obtain good measurements.

Dual element transducers are normally used in pulse-echo mode for finding defects, and in echo-echo mode for through coating measurements.

Dual element delay line transducers are usable over a range of 0.025 inches to 20 inches depending on the material, frequency, and diameter.

A limitation of dual element delay-line transducers is the V shaped sound path. Because the sound travels from one element to another, the time versus thickness relationship is non-linear. Therefo re, a correction table in the instruments software is used to compensate for this error.

Dual Element Transducer showing V-path of signal

Searching for small defects

Dual element delay line transducers are especially useful in searching for small defects. In the pulse-echo mode with high amplifier gain, very small defects can be measured. This is very useful during corrosion inspections overall. The dual element style transducer will find wall deterioration, pits, and any porosity pockets during tank and pipeline inspections.

Echo-Echo Mode – Thru-Paint (E-E)

The echo-echo mode measures between two reflections. This technique is commonly used to eliminate errors from surface coatings and also to make measurements in multiple layered materials. The disadvantage is that two echoes are needed which requires a much stronger echo (reflection).

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Dual Element Transducer in Echo to Echo mode

Echo-Echo Verify Mode – Thru-Verify (E-EV)

The echo-echo verify mode measures between 3 reflections. Similar to E-E mode, this technique is commonly used to eliminate errors from surface coatings and also to make measurements in multiple layered materials. The primary benefit of this mode, is that a comparison is made, between the 2nd and 3rd echoes, to verify that a peak jump has not occurred, providing an additional level of confidence to the measurement. The disadvantage is that 3 reflections are needed which requires the use of gates with controllable thresholds to adjust for sensitivity over a given measurement rang e.

Dual Element Transducer in Echo to Echo mode

Pulse Echo Coating Mode – Coating On (PECT)

A custom hybrid combination mode using properties from the basic modes along with a group of special techniques and theoretical wave phenomena’s to measure coating and material thicknesses at the same time, while still retaining the ability to locate flaws and pits in materials. Therefore, the best description for this hybrid mode is Pulse-Echo Coating mode.

Coating Mode – Coating Only (CT)

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Once again, this is a custom hybrid combination mode using special techniques to effectively measure the thickness of coatings that are either adhered to metallic surfaces or in stand alone form . In this mode a two point calibration must be performed. If the user will be measuring coating that has been applied to a metal surface, the calibration must be performed using coating samples coupled to a metal surface when calibrating. To explain further, a drop of couplant must be applied in between the coating samples and metal surface. If the coating has not been applied to a metal surface, the calibration should be performed accordingly.

Pulse-Echo Temperature Compensated Mode – Temp Comp (PETP)

This is a custom mode that combines pulse-echo and electronic zero techniques to automatically adjust for temperature changes in the transducer as a result of an increasing/decreasing temperature gradient in the test material. Note: rough surface conditions can have an effect on the overall accuracy in this mode. If the surface condition is in question, the pulse-echo mode should be used in conjunction with performing an off block automatic zero as the temperature gradient changes.

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CHAPTER FIVE SELECTING THE MEASUREMENT MODE

5.1 The setup library

The CMXDL contains 64 user configurable preset locations to store custom setups for easy recall. These setups can be optimized for the user’s specific application needs and can also be stored on a PC and transferred bi-directionally using Dakota’s PC interface software included with the instrument.

The setups supplied with the instrument cover some of the more typical applications commonly used with this type of instrument. These setups can be recalled, modified, and overwritten to one of 64 setup locations. Therefore, these factory setups can also be considered a good starting point to be modified for custom applications. The PC software includes a default setup file that can be uploaded to the gauge at any time to restore factory settings. However, it is recommended that the user consider saving modif ied setups to an empty location rather than overwriting the factory setups in the CMXDL. Once again, these factory settings are excellent starting points for custom setups.

5.2 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. The CMXDL has been optimized for cast materials. Cast iron applications require 1 - 5MHz frequencies, and cast aluminum requires a 10MHz frequency. Plastics typically require lower frequencies depending on the thickness and make-up of the material. Larger diameters offer greater penetration power because of the crystal size, for difficult to measure materials.

Corrosion & Pit Detection in steel and cast materials

Use pulse-echo mode whenever attempting to locate pits and flaws. Typically a 5MHz transducer, or higher, will be used for these types of applications. Use low frequencies for greater penetration and use higher frequencies for better resolution.

Measuring Material & Coatings

The pulse-echo coating mode should be used when both material and coating thickness are required, while still requiring the ability to detect flaws and pits. A special coating style transducer is required for use in this mode. There are a variety of coating transducers in various frequencies available from Dakota.

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Thru Paint & Coatings

Often times, users will be faced with applications where the material will be coated with paint or some other type of epoxy material. Since the velocity of th e coating is approximately 2.5 times slower than that of steel, pulse-echo mode will induce error if the coating or paint is not completely removed. By using echo-echo mode, the user is able to successfully measure through both, the coating and steel, and completely eliminate the thickness of the paint or coating. Therefore, the steel can be measured without having to remove the coating prior to measuring. Users will often use pulseecho mode and echo-echo mode in conjunction when performing inspections on coated materials.

Thru coating measurements require special high damped transducers. The most common transducers are the 3.5, 5, and 7.5MHz hi damped transducers. These transducers are suitable for use in both pulse-echo and echo-echo modes. This conveniently enables the user to accurately measure overall material thickness using the thru Coating mode, and then conveniently switch to pit detection mode without changing transducers. The ¼” 5MHz Hi damped transducer is the most commonly used transducer for standard thru coating applications.

Coating Only The coating only mode should be used when the application calls for coating

measurements only and the user is not interested in the thickness of the material the coating has been applied to. This mode can also be used as a stand alone coating thickness gauge, where the coating has not been applied to another material surface. An auto identified coating probe must be attached to the CMXDL in order to enable this mode.

Thin materials

Use pulse echo mode and a high frequency transducer for these types of applications. The most common transducers are the 7.5MHz and 10MHz models with extra resolution. The higher frequencies provide greater resolution and a lower minimum thickness rating overall.

High temperature

Use and select a special 2.25MHz and 5 MHz High temperature transducer for these types of applications. Both pulse-echo and echo-echo modes will also work for these applications. However, echo-echo mode will eliminate error caused by temperature variations in the delay line of the transducer.

Noisy Material

Materials such as titanium, stainless steel, and aluminum may have inherent surface noise issues. This is a signal that appears at the surface of the material when using a dual element delay lin e probe. Select a higher frequency transducer to reduce this noise – 7.5MHz and higher for better resolution.

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Restricted access

Measuring materials with extreme curvatures or restricted access, higher frequencies with smaller diameters should be considered. The smallest diameter uses 3/16” crystals with a contact area of .250”. Custom transducers are available on request.

5.3 Factory Setup Chart

Num Name Comment 1 Gn/AGC Velocity

1 Enter Custom Name 2 … 3 … 4 … 5 … 6 … … …

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CHAPTER SIX MAKING MEASUREMENTS

The steps involved in making measurements are detailed in this section. The following sections outline how to setup and prepare your CMXDL for field use.

An automatic or manual zero must always be performed. The auto zero is an off block electronic zero that does not require a zero reference block. This will most always be the zero option of choice, as it makes the zeroing process very easy and convenient to perform. However, If the manual zero option is enabled, the probe zero must be measured on the reference disk (battery disk) attached to the top of the instrument. The zero compensates for variations 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 a material chart in the manual, selected from a material list in the CMXDL, or for greater precision determined from a sample of the test material that has been mechanically measured. 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 49.

When measuring curved materials, it is 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 mounted to the CMXDL is not used. This is called twopoint calibration and is described on page 51.

6.1 Auto Probe Recognition & Selecting The Transducer Type

The first step in using the CMXDL is to plug the transducer into the gauge and power the unit up. The CMXDL has a special built -in automatic probe recognition feature that will check to see if the probe plugged into the gauge is an auto recognized probe type. If so, the CMXDL will display a message indicating the transducer type and ask the user for confirmation to use the identified probe. If the transducer is not an auto recognized probe, the CMXDL will display a message indicating the transducer type has not been recognized, and force the user to select a transducer type from a list of transducers according to frequency and diameter. Whether the transducer is auto recognized or selected from a predefined list, the CMXDL will recall specific properties about the transducer. Note: Once the transducer has been selected, the CMXDL will

store and recall this transducer type every time the CMXDL is powered on/off. The type will only change if the user physically selects another type from the list, or selects a previously saved setup. Therefore, if you have previously gone through this section and selected the transducer you are using, proceed to the next section. Use the following steps to select your transducer type. Note: If the transducer is not

identified on power up, be sure the transducer type selected is the same as the transducer plugged into the CMXDL. Failure to do this will result in erroneous

measurements:

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In this first example the transducer was automatically identified:

Probe Automatically Recognized

1) Press the OK key once to use the identified probe, or ESC to display a list of

optional transducers. Note: if the CMXDL recognizes a specific transducer,

somehow identified the probe in error. .

2) Assuming the CMXDL recognized the probe and the OK key was pressed, the CMXDL will advance to a Zero Probe menu. If the transducer was

identified as a special transducer capable of measuring coating thickness, a menu will be displayed allowing the user the ability to toggle the coating thickness display on/off as follows:

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3) Press the UP and DOWN arrow keys to toggle the coating option on/off.

4) Wipe all couplant from the transducer face and proceed to the Probe Zero section that follows.

In this second example the transducer was not identified and will force the user to select the transducer type fr om a predefined list of transducers:

Selecting the Transducer Type

5) Press the OK or ESC keys to display the factory list of transducer types (by diameter and frequency).

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6) Press the UP and DOWN arrow keys to scroll through the transducer list until the appropriate type is highlighted.

7) Press the ENTER key to select the transducer type and display overwrite existing probe screen.

8) Press the OK key to overwrite the existing probe type with the newly selected probe type. The zero probe screen will be displayed. Proceed to the zero probe section that follows.

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6.2 Probe zero

The next step is to perform a probe zero. The zero function is a very important and necessary function that must be done prior to calibration. It should be done on a regular basis. In fact, the CMXDL has been programmed to force this issue at regular intervals during operation if it hasn’t been done. If the CMXDL is not zeroed correctly, all the measurements taken may be in error by some fixed value. When the CMXDL is using the auto zero (electronic zero), the CMXDL can be in any measurement mode. However, when the manual zero is being used, the CMXDL must be in pulseecho mode in order to perform the zero. The CMXDL will also see to it that this occurs by simply forcing the gauge into this mode when zero. Therefore, if the

CMXDL is in the echo-echo measurement mode and a manual zero is being

performed, the CMXDL will put the gauge into pulse-echo mode automatically before performing the zero. While this is a very convenient feature of the CMXDL, the user should be sure to check the measurement mode following calibration to be sure the

CMXDL is in the desired mode. The following steps outline both of these techniques.

The CMXDL is equipped with two zero options:

1) Off Block Zero (Automatic Probe Zero) – When this feature is enabled the

CMXDL will do an electronic zero automatically, eliminating the need for a zero

disk or block.

2) On Block Zero (Manual Probe Zero) – When this feature is enabled the transducer must be placed on the probe zero disk (battery cover located on the top of the unit.

Both zero procedures are outlined as follows:

Performing an Auto Probe Zero (Off Block)

Coating Probe Identified Coating Probe Not Identified

1) Be sure all couplant has been removed from the face of the transducer.

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2) Press the OK key to perform the automatic probe zero, or ESC key to cancel the zero operation.

Coating Probe Identified Coating Probe Not Identified

3) The screens illustrated above will be briefly displayed followed by the main measurement screen. The CMXDL is ready to be calibrated.

Performing a Manual Probe Zero (On Block)

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Note: When the zero probe option is set to manual, the probe zero disk (battery cap) located on the top of the gauge will be used as a zero standard

and the warning screen illustrated above will be displayed.

1) Press the OK or ESC keys to enter the main measurement screen and begin the manual zero process.

2) Apply a drop of couplant on the transducer and place the transducer in steady contact with the probe zero disk and obtain a steady reading.

4) Press the UP and DOWN arrow keys to scroll through the sub menu items until ZERO PROBE is highlighted.

Coating Probe Identified Coating Probe Not Identified

5) Press the ENTER key to display the confirmation screen.

6) If a coating transducer was identified use the UP and DOWN arrow keys to toggle coating on/off.

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7) Press the OK key to complete the probe zero function, or ESC key to cancel the probe zero function.

8) Remove the transducer from the probe zero disk, and proceed to the calibration section.

Note: The value that is displayed will change depending on the current velocity setting in the CMX. Disregard the number that is displayed. It is not important. What is important is accurately performing the steps outlined above

to insure reliability of the probe zero calculation.

6.3 Material Calibration

In order for the CMXDL 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 soun d 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 fixed percentage.

The One Point calibration is the simplest and most commonly used calibration method - optimizing linearity over large ranges. The Two Point calibration allows for

greater accuracy over small ranges by calculating the probe zero and velocity. The

CMXDL provides four simple methods for setting the sound-velocity outlined below:

Known Velocity

If the material velocity is known, the user may wish to simply enter the velocity number into the CMXDL, rather than have the CMXDL calculate the velocity value using a known thickness on a material sample. The steps for entering the velocity are outlined below:

Using a Known Material Velocity

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1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until VELOCITY is highlighted.

3) Press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

6) Repeat steps 4 & 5 until the velocity number is correctly displayed.

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7) Press the OK key to set the velocity and return to the menu screen, or ESC to cancel entering the velocity.

8) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

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Known Thickness

Sometimes the sound velocity of a material is unknown. In this case a sample with one or two known thicknesses can be used to determine the sound velocity. As previously discussed, the CMXDL has a one or two point calibration option. The one point calibration option is most suited for linearity over large ranges, as noted above. The user should also consider calibrating on high side of the intended measurement range, when using the one point option, minimize overall error. 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 CMXDL for calibration in the field:

One Point Calibration

Note: Be sure that the probe zero procedure 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.

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ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

3) Use the UP and DOWN arrow keys to scroll through the sub menu items until MATL 1PT is highlighted.

4) Press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the known thickness value is correctly displayed.

8) Press the OK key to calculate the velocity and return to the menu screen, or ESC to cancel the one point calibration.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

Note: CHECK YOUR CALIBRATION! Place the transducer back on the calibration point. The thickness reading should now match the known thickness. If the thickness is not correct, repeat the steps above.

At some point there may become a requirement for improved accuracy over a smaller measurement range. In this case, a two point calibration would be most suited for

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the job. For example, if the measurement range was .080” (2.03mm) to .250” (6.35mm), the user would perform a one point calibration on a known thickness sample close to .250” (6.35mm), followed by a two point calibration close to .080” (2.03mm). When a two point calibration is performed, the CMXDL calculates the zero and the velocity. The following steps outline this procedure:

Two Point Calibration

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.

display, is fully lit and stable. Press the MENU key once to activate the menu items tab. Press the MENU key mul tiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

3) Use the UP and DOWN arrow keys to scroll through the sub menu items until MATL 2PT is highlighted.

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4) Press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the known thickness value is correctly displayed.

8) Press the OK key to calculate the velocity and return to the menu screen, or ESC to cancel the one point calibration.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

Note: CHECK YOUR CALIBRATION! Place the transducer back on the calibration point. The thickness reading should now match the known

thickness. If the thickness is not correct, repeat the steps above.

Basic Material Type

If the material velocity is unknown, and a sample thickness cannot be taken from the material, the user may opt to choose a basic material type from a list with approximate velocity values according to various material types. It’s important to note that these velocities will not always be an exact representation of the material

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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

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until MAT is highlighted.

3) Press the ENTER key to display the list of material types.

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4) Press the UP and DOWN arrow keys to scroll through the material list until the appropriate material is highlighted.

5) Press the ENTER key to overwrite the material type and display the menu items with the new material type selected.

6) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

To calibrate the CMXDL for a specific type of coating using samples with known thicknesses, please refer to the chapter 9 – Pulse-Echo Coating (PECT) or Coating (CT) for a complete explanation of using the CMXDL for coating measurements.

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CHAPTER SEVEN USING THE DIGITS & B-SCAN DISPLAYS

A key feature of the CMXDL is the ability to toggle between two different display options, Digits and B-Scan. The Digits view provides the user with a large digital readout of the thickness. Both views also include a scan bar features that uses a bar graph to indicate thickness. The Scan bar can be very handy while scanning a tank or pipe wall by graphically displaying deflections from pits or internal flaws, rather than having to constantly watch for changes in the digital readout. It’s just another visual aid to alarm the user when something out of the ordinary has been detected.

The B-Scan display is also very useful when scanning surfaces and viewing the cross section of the test material. It provides a convenient way of visually profiling, or drawing a picture of, the blind surfaces during a scan. The B-Scan display is also equipped with a scan bar representing the overall thickness. Once again, the scan bar gives the user a visual indication when a flaw or defect has been passed over during the scan process. The scan bar will deflect off of the defect and return back to the overall thickness. In this chapter we’ll outline some of the fine adjustment features of the CMXDL. We’ll take a better look at these options in this chapter.

Note: In order to recall and use the new adjustments made to the CMXDL at a later time, the user must save the modified settings in one of the setup locations. Refer page 112 for more information on setups.

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7.1 Display Views

DIGITS VIEW

DIGITS

The Digits view is a basic digital thickness gauge look and feel. The larger digits make it much easier for the operator to monitor the thickness readings. The Scan Bar has also been added to the Digits view to provide the user with yet another visual tool for easily monitoring changes in thickness readings due to internal flaws or defects.

The following is a list of the viewable features on the display:

A. Repeatability/Stability Indicator – This indicator should be commonly used

second, depending on which measurement mode and features are enabled. B. Battery Icon – Indicates the amount of battery life the CMXDL has remaining. C. Velocity – The material velocity value the CMXDL is currently using or

calibrated for. Displayed in English or Metric units, depending on the what

units the gauge is set for. D. Feature Status Bar – Indicates the features currently enabled and in use in

the following order:

• Measurement Mode

• Differential Mode

• High Speed Scan Mode

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• Alarm Mode

• Gain Setting

E. Digital Material Thickness Value – Extra large font size for viewing ease. F. Scan Bar – Another view of material thickness in a deflection style horizontal

bar. This is another visual tool that would enable the user the ability to see

thickness changes during high speed scans from flaws and pits. G. Units – The current measurement units being used (English, Metric). H. Coating Thickness Value – Displays the actual thickness of any coating

adhered to a metallic material surface (PECT Mode), or a coating adhered to a

non-metallic surface (CT Mode). I. Minimum Material Thickness – Part of the Alarm feature. Displays the

minimum thickness value found during a scan. J. Maximum Material Thickness – Part of the Alarm feature. Displays the

maximum thickness value found during a scan.

B-Scan View

B-Scan

The B-Scan displays a time based cross section view of test material. This view is commonly used to display the contour of the blind, or underside, surface of a pipe or tank application. It is very similar to a fish finder. If a flaw or pit is located during a scan, the B-Scan will draw the pit on the screen. The solid black rectangle in the diagram at location K represents the cross section, or side view of the material. The B-Scan view draws at a rate of 7 seconds per screen from right to left. Also notice at location K, the pits and corroded bottom surface of the material.

It’s important to note that the measurement range on the display be set wide enough, so that the maximum thickness of the material can be viewed on the display. Using the diagram above, if the material thickness was actually 1.75”, the underside of the material would not be viewable according to the current range at 0.00” – 1.00”. All

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the user would see is a black screen from 0.00” – 1.00” with no view of the bottom contour at 1.75”.

The following is a list of the viewable features on the display:

A. Repeatability/Stability Indicator – This indicator should be commonly used

calibrated for. Displayed in either English or Metric units, depending on the

what units the gauge is set for. D. Feature Status Bar – Indicates the features currently enabled and in use in

the following order:

• Measurement Mode (P-E, PECT, PETP, E-E, COAT)

• Differential Mode (ON/OFF)

• High Speed Scan Mode (ON/OFF)

• Alarm Mode (ON/OFF/AUDIBLE)

• Gain Setting (VLOW, LOW, MED, HI, VHI)

E. Digital Material Thickness Value – Smaller font size when the B-Scan

display view is enabled. F. Scan Bar – Another view of material thickness in a deflection style horizontal

bar. This is another visual tool that would enable the user the ability to see

adhered to a metalli c material surface (PECT Mode), or a coating adhered to a

non-metallic surface (CT Mode). I. Minimum Material Thickness – Part of the Alarm feature. Displays the

minimum thickness value found during a scan. J. Maximum Material Thickness – Part of the Alarm feature. Displays the

maximum thickness value found during a scan. K. B-Scan Display – Cross section view of the material. Provides the user with

graphical view of the opposite/blind surface (i.e. inside pipe wall surface), to

give the user some idea of the condition, or integrity of the material being

tested.

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7.2 Activating B-Scan View

To use the B -Scan feature it must be enabled in the display menu. The following steps will help you do just that:

Enabling the B- Scan Feature

1) Press the MENU key once to activat e the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the DISP menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until VIEW is highlighted.

3) Press the LEFT and RIGHT arrow keys to toggle DIGITS or BSCAN. When the correct view is being displayed continue on to setting the B-START or B- DEPTH values, or press the MEAS key to return to the measurement screen and begin taking readings.

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7.3 Adjusting the B-Scan Start (B-START) & Depth (B-DEPTH)

In order to use the B-Scan and Scan Bar features of the CMXDL effectively, the starting depth and overall depth must be setup correctly. This can be adjusted using

the B-START and the B-DEPTH features of the CMXDL. The B-START refers to the starting depth or thickness value displayed. Example: If you want your B-Scan or

Scan Bar to start at a zero thickness value, then B-START must be set to 0.000”. If you want the B-Scan and Scan Bar to start displaying at .125”, then B-START must be set to .125”. B-DEPTH represents overall viewable thickness range being tested. Example: If your measuring tank walls with a total thickness of .300”, and your B- START has been set to 0.000”, you might consider setting your B-DEPTH value to something like 0.400” to cover the entire thickness range being tested. You might also consider B-DEPTH as a zoom feature for both the B-Scan and Scan Bar. Why? Because the larger the overall thickness range view (B-DEPTH), the smaller the noticeable shifts in the Scan Bar and B-Scan presentation. Therefore, it’s best to set the B-START and B-DEPTH to reasonable values that zoom in and optimize your graphic presentation.

Starting depth (B-START)

The starting B-START, or starting depth, is the starting thickness value. Often times this value will simply be set to zero in order to start measuring at 0.000”. The only

time this value will be set to something other than zero, is if the user needs to zoom in even closer. When will this be the case? If the user is testing a material that’s 1 inch in thickness and knows that the potential corrosion is only on the back surface of the material and not possibly deeper than .200”. In this case, the user may wish to set the B-ST at .700” to zoom in closer to the actual area being tested. In turn, the BDEP might be set at 1.100” in order to cover the entire range respectively. This will offer the user better resolution for both the B-Scan and Scan Bar graphical presentations.

Note: Once the range is set, it will remain the same for all the views respectively.

The procedures to adjust the starting depth (B-START) are outlined below:

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Adjusting the Starting Depth (B-START)

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the DISP menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until B-START is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct B-Start value is being displayed, proceed to step 8.

4) Alternatively, press the ENTER key to display the Digits Edit Box.

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5) Press the UP and DOWN arrow keys to scroll the h ighlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the B-Start value is correctly displayed.

8) Press the OK key to set the B-Start value and return to the menu screen, or ESC to cancel entering the B-Start.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

Overall range (B-DEPTH)

Once again, just to reiterate, B-DEPTH is the overall viewable thickness range being tested. This should be set to a value slightly larger then the expected maximum range being measured. The procedures to adjust the overall thickness range viewed

(B-DEPTH) are outlined below:

Adjusting the Overall Depth (B-DEPTH)

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the DISP menu is highlighted and displaying the submenu items.

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2) Use the UP and DOWN arrow keys to scroll through the sub menu items until B-DEPTH is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct width is being displayed, proceed to step 8.

4) Alternatively, press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the B-Depth value is correctly displayed.

8) Press the OK key to set the B-Depth and return to the menu screen, or ESC to cancel entering the B-Depth.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

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7.4 Gain

The gain, or amplification of the return echoes, can be adjusted in the CMXDL to accommodate a variety of 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, by detecting on noise rather than the actual material back wall itself. Not enough gain may result in intermittent detection. It may also result in lack of detection on internal flaws, pits, or porosity. The gain can easily be compared to the volume control of a home stereo system. 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 CMXDL has three gain settings (VLOW, LOW, MED, HI, VHI). The gain range is 42dB – 50dB in 2dB increments. Note: The CMXDL 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, the user can assume that the material is either very noisy aluminum, or granular cast iron. This would be a good time to change the

CMXDL to low er gain setting and see if the reading settles down and become stable.

How do I know when to increase the gain? Often times the user will be trying to measure a material that is hard to penetrate or pass sound through. This may be due to the material type, or overall thickness of the material. When a material is hard to pass sound through because of the thickness or general make-up, it would be a good time to consider switching the CMXDL into a higher gain setting. Another example might be the need to increase overall sensitivity for locating fine pits or flaws. In any case, the selectable gain settings offer the user some additional options to resolve and overcome application issues.

Note: When the echo-echo thru-paint measurement mode is selected, the manual gain feature is disabled and grayed out in the menu items. In this mode, the CMXDL

switches to an automatic gain mode (AGC) that optimizes the gain setting automatically in the hardware of the CMXDL.

The procedures to adjust the Gain are outlined below:

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Adjusting the Gain

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab

left, until the TUNE menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until GAIN is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct Gain is being displayed, press the MEAS key to return to the

measurement screen and begin taking readings.

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CHAPTER EIGHT THRU PAINT MEASUREMENT TECHNIQUE

8.1 Introduction to Thru Paint Measurement

The principle behind thru paint measurement is by measuring the time between two backwall echoes returning from the test material. Since both of these backwall 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 can be measured. This feature saves the user a great deal of time scraping and removing the coating from tanks and pipes during the inspection process.

The primary purpose of thru paint measurement is to determine actual or overall material thickness by eliminating the coating thickness. Thru paint mode cannot be used for flaw or pit detection. Therefore, inspectors may need to use echo-echo thru paint mode in conjunction with the standard pu lse-echo flaw detection mode for some applications. Chassis tubing inspectors and sanctioning bodies will use the echoecho mode for tubing with powder coatings, and pulse-echo mode for tubing without coating. The combination of using both modes is ideal for the advanced inspectors needs.

8.2 Using Thru Paint Mode

The first thing to note in this section, is that by selecting the transducer type from the list of probes stored in the CMXDL, a basic echo-echo thru paint configuration is recalled from memory. Each of the transducers in the list contain s pre-configured echo-echo settings. The standard transducer that will be used for common steel applications is a ¼” 5MHz high damped transducer (1/4IN – 5.0MHZ HD) . This is the recommended transducer for this industry and should be used for thru paint applications. Any of the auto recognition coating transducers are also high damped transducers and will work in echo-echo mode as well.

Note: When a transducer is selected for use, all of the measurement modes available for use with this transducer can easily be determined by pressing the multimode button on the keypad. The CMXDL has been programmed to identify the modes available to a specific transducer.

Once the transducer type has been selected and the appropriate calibration procedure completed, the CMXDL can toggle between pulse-echo (flaws & pits), and

echo-echo (thru paint) modes by simply pressing the MULTI MODE key located on the keypad. Refer to page 39 for additional information.

The CMXDL can also be configured for thru paint applications by selecting a factory setup stored in the list of setups in the CMXDL. Refer to page 112 for information on recalling a setup. Once either the transducer type or setup has been selected, the inspector is ready to begin making measurements.

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CHAPTER NINE PULSE-ECHO COATING & COATING TECHNIQUES

9.1 Introduction to Pulse- Echo Coating Measurement (PECT)

In the previous sections we’ve discussed the need for detecting pits and flaws (pulseecho) in materials, along with the requirement to measure through and eliminate errors caused by coated materials (echo-echo). Until now, both modes were needed in order accomplish both tasks. Pulse-echo mode was used for flaw detection, an d echo-echo mode was used to eliminate the coating thickness and provide a nominal material thickness only. With this in mind, it often became cumbersome toggling between both modes respectively.

In a majority of applications involving coat ed materials, inspectors are often interested in monitoring both the thickness of the material, as well as the thickness of the coating. Therefore, the CMXDL has been designed to provide the user with the ability to measure the material and coating thicknesses simultaneously, while maintaining the ability to detect flaws and pits all in a single mode called Pulse-Echo Coating (PECT) . This is accomplished by using a custom hybrid combination mode utilizing properties from the basic modes along with a group of special techniques and theoretical wave phenomena’s.

The CMXDL is preset to a coating velocity of 0.0850 in/µsec (2159 m/sec) from the factory. This velocity is a very close approximation of the common coating velocities found in the field. However, the CMXDL also has a built -in one and two point calibration options to calibrate to coating samples with a known thicknesses.

There are two coating modes built into the CMXDL:

1) Pulse-Echo Coating (PECT) – used during inspections where both the material and coating thicknesses are required.

2) Coating Only (CT) – used during inspections where only the coating thickness is required.

9.2 Enabling Pulse-Echo Coating Mode (PECT) & Coating (CT)

When the CMXDL is initially powered up, the gauge will automatically check to see if the transducer plugged into the gauge can be recognized. All Dakota Ultrasonics coating enabled transducers are equipped with the auto recognition feature. If the

CMXDL doesn’t recognize that a special coating enabled transducer is plugged into

the gauge, the coating feature will be disabled entirely. There are a number of coating enabled transducers available from Dakota. Please contact us with your application requirements for additional information on frequencies and diameters currently offered.

The coating modes can be enabled in three different ways:

1) On Power up and probe recognition.

2) By pressing MULTI MODE keypad.

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3) From the tabbed menus under TUNE, MEASURE MODE.

The steps that follow will demonstrate all three methods in the order listed above:

Probe Aut omatically Recognized (PECT only)

1) Press the OK key once to use the identified probe, or ESC to display a list of

optional transducers. Note: if the CMXDL recognizes a specific transducer,

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3) Press the UP and DOWN arrow keys to toggle th e coating option on/off.

Multi Mode Key Pressed (PECT & CT)

Applied to Metals Not Applied to Metals

1) Press the MULTI MODE key located on bottom left of the keypad to display the MEASURE MODE options menu.

2) Press the UP and DOWN arrow keys to highlight the COATING ON (PECT) or COATING ONLY (CT) menu option.

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3) Press the ENTER key to enable the coating option, or ESC to cancel changing the measure mode, and return to the main measurement screen.

Measure Mode (Tabbed Menus) – (PECT & CT)

Applied to Metals Not Applied to Metals

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the TUNE menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until MEASURE MODE is highlighted.

3) Press the LEFT and RIGHT arrow keys to scroll the modes.

4) When the correct MODE is being displayed, press the MEAS key to return to the measurement screen and begin taking readings.

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9.3 Zero Coating

CMX DL High Performance Material & Coating Thickness Gauge

In order to account for very slight electronic differences in transducers of the same type, frequency, and diameter, the CMX feature. This enables the CMX

DL+

to obtain very accurate readings on coatings,

DL+

has been equipped with a “zero coating”

eliminating potential errors incurred from slight differences in the manufacturing processes. The procedure is outlined below:

Performing a Coating Zero

1) Press the MULTI MODE key once to activate the measurement mode options.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until Coating Only (CT) mode is highlighted.

3) Press the ENTER key to select the measurement mode and return to the measurement screen.

4) Apply a drop of couplant on the transducer and place the transducer in steady contact with the probe zero disk (battery cover) and obtain a steady reading.

Note: The coating measurement displayed will potentially be a value greater or less than 0.

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6) Use the UP and DOWN arrow keys to scroll through the sub menu items until ZERO COATING is highlighted.

7) Press the ENTER key to display the confirmation screen.

8) Press the OK key to zero the coating and return to the PRB menu, or ESC to cancel the coating zero process.

9) Press the MULTI MODE key once to activate the measurement mode options.

10) Use the UP and DOWN arrow keys to scroll through the sub menu items until Coating On (PECT) is highlighted.

11) Press the ENTER key to select the measurement mode and return to the measurement screen, and begin taking readings. Proceed to the coating

calibration section.

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9.4 Coating Calibration (PECT)

Known Velocity

If the coating velocity is known, the user may wish to simply enter the velocity number into the CMXDL, rather than have the CMXDL calculate the velocity value using a known thickness on a coating sample(s). The steps for entering the velocity are outlined below:

Using a Known Material Velocity

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until COATING VEL is highlighted.

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3) Press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

6) Repeat steps 4 & 5 until the velocity number is correctly displayed.

7) Press the OK key to set the velocity and return to the menu screen, or ESC to cancel entering the velocity.

8) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

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Known Thickness

Sometimes the sound velocity of a coating material is unknown. In this case a sample with a known thickness can be used to determine the sound velocity of the coating. As previously discussed, the CMXDL offers a one point calibration option for coating in PECT measurement mode. It is also import to reiterate that the coating sample must be coupled to a metallic material in order to perform the calibration . The calibration shou ld also consider calibrating on high side of the intended measurement range, when using the one point option, minimize overall error. For example, if the measurement range of the coating will be from .040” - .080” (1.0mm

2.3mm), a coating closest to .080 (2.0mm) should be used. Note: It’s always handy

to carry a set of mechanical calipers to use in conjunction with the CMXDL for calibration in the field:

One Point Calibration

Note: Be sure that the probe zero procedure has been performed prior to

performing this calibration procedure.

1) Physically measure an exact sample of the coating using a set of calipers or a digital micrometer.

Note: The coating sample must be coupled to a metallic material in order to be calibrated.

2) Apply a drop of couplant on a piece of metal and place the coating sample on the metal over the couplant. Apply a drop of couplant on the transducer

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and place the transducer in steady contact with the coating and 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. Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

3) Use the UP and DOWN arrow keys to scroll through the sub menu items until COATING 1PT is highlighted.

4) Press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the known thickness value is correctly displayed.

8) Press the OK key to calculate the velocity and return to the menu screen, or ESC to cancel the coating one point calibration.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

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Note: CHECK YOUR CALIBRATION! Place the transducer back on the calibration point. The coating thickness reading should now match the known

thickness. If the thickness is not correct, repeat the steps above.

9.5 Introduction to Coating Measurement (CT)

In the previous sections we’ve discussed how to setup and use the coating feature for use in conjunction with material thickness and flaw and pit detection. The CMXDL also has the capability to be used for general coating measurements. This measurement mode is called Coating (CT) and can be enabled using the same methods as described in a previous section above.

When the Coating Only (CT) mode is enabled, a two point calibration on the coating samples must be performed. This is to ensure linearity over the coating measurement range will be achieved. Important note: If coating measurements will be made with the coating applied to a metal surface, the calibration must be done in the same manner, with the samples coupled to a metal surface. However, if the coating will be measured as a stand alone material, the calibration must be performed the same way .

9.6 Two Point Coating Calibration (CT)

Known Thickness

The following section will demonstrate the two point coating calibration procedure. This example demonstrates a coating thickness range of .040” - .120” (1 – 3 mm) as follows:

Note: It’s always handy to carry a set of mechanical calipers to use in conjunction with the CMXDL for calibration in the field:

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One Point Calibration

Note: Use the maximum coating sample for the one point calibration first.

1) Physically measure the thicker of the two samples of coating, as close as possible to the maximum expect ed coating measurement range, using a set of calipers or a digital micrometer.

Very Important : If coating measurements will be made with the coating applied to a metal surface, the calibration must be done in the same manner, with the samples coupled to a metal surface. However, if the coating will be measured as a stand alone material, the calibration must be performed the same way.

2) Apply a drop of couplant on the transducer and place the transducer in steady contact with the thicker of the two coating and samples fist. Be sure that the reading is stable and the repeatability indicator, in the top left corner

of the display, is fully lit and stable. Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

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3) Use the UP and DOWN arrow keys to scroll through the sub menu items until COATING 1PT is highlighted.

4) Press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat st eps 5 & 6 until the known thickness value is correctly displayed.

8) Press the OK key to calculate the velocity and return to the menu screen, or ESC to cancel the coating one point calibration.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

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Two Point Calibration

Note: Use the minimum coating sample for the two point calibration.

1) Physically measure the thinner of the two samples of the coating, as close as possible to the minimum expected coating measurement range, 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 thinner of the two coating and samples. Be sure that the reading is stable and the repeatability indicator, in the top left corner of

the display, is fully lit and stable. Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right and the ESC key multiple times to tab left until the CAL menu is highlighted and displaying the submenu items.

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3) Use the UP and DOWN arrow keys to scroll through the sub menu items until COATING 2PT is highlighted.

4) Press the ENTER key to display the Digits Edit Box.

5) Press the UP and DOWN arrow keys to scroll the highlighted value.

6) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

7) Repeat steps 5 & 6 until the known thickness value is correctly displayed.

8) Press the OK key to calculate the velocity and return to the menu scr een, or ESC to cancel the coating one point calibration.

9) Finally, press the MEAS key to return to the measurement screen and begin taking readings.

Note: CHECK YOUR CALIBRATION! Place the transducer back on both calibration points. The coating thickness readings should now match the known thickness values of each sample. If the thickness is not correct, repeat the

steps above.

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CHAPTER TEN ADDITIONAL FEATURES OF THE CMXDL

10.1 High Speed Scan

The High Speed Scan feature of the CMXDL increases the overall repetition rate to a maximum of 140Hz with a high speed screen refresh rate of 25 times a second. This feature enables a user to make scanned passes over an arbitrary length of the test material, while still maintaining a reasonable representation of thickness over th e scanned area or region. This feature can be used in conjunction with High and Low alarm limits features to dynamically keep track of both values. The feature is typically used to provide a better representation of the area scanned, by taking more readings at a faster rate repetition rate.

The procedure to use the SCAN MODE feature is outlined below:

Using the Scan Mode

1) Press the MENU key once to activate the menu items tab. Press the MENU

key multiple times to tab right and the ESC key multiple tim es to tab left until the UTIL menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items

until SCAN MODE is highlighted.

3) Use the LEFT and RIGHT arrow keys to toggle the SCAN MODE on/off.

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4) Press the MEAS key to return to the measurement screen.

10.2 Alarm Mode

The Alarm Mode feature of the CMXDL provides the user with 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 is within the manufacturer specifications. There are two limits, or alarm values, that can be setup in the CMXDL

– ALARM LOW and ALARM HIGH limits. However, the user may choose to activate and utilize only one of the limit va lues, depending on their specific application

requirements. The procedures to use the ALARM MODE feature are outlined below:

Toggle Alarm (on/off)

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the UTIL menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items

until ALARM is highlighted.

3) Use the LEFT and RIGHT arrow keys to toggle the ALARM on/off/audible.

4) Continue on to the next section “Setting the Alarm Low Limit”.

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Setting the Alarm Low Limit

1) Assuming the ALARM is ON, use the UP and DOWN arrow keys to scroll through the sub menu items until ALARM LOW is highlighted.

2) Press the LEFT and RIGHT arrow keys to scroll the value. When the correct alarm value is being displayed, proceed to step 7.

3) Alternatively, press the ENTER key to display the Digits Edit Box.

4) Press the UP and DOWN arrow keys to scroll the highlighted value.

5) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

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6) Repeat steps 4 & 5 until the ALARM LOW value is correctly displayed.

7) If only one limit will be used, press the MEAS key to return to the

measurement screen and begin taking readings. Otherwise, continue on to set the ALARM HIGH limit.

10.3 Differential Mode

The Differential Mode of the CMXDL provides the user with the ability to set a nominal value, according to what the expected thickness should be, and measure the +/- difference from the nominal va lue 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:

Toggle Differential (on/off)

2) Use the UP and DOWN arrow keys to scroll through the sub menu items

until DIFFERENTIAL is highlighted.

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3) Use the LEFT and RIGHT arrow keys to toggle the DIFFERENTIAL on. A

value will appear to the right of DIFFERENTIAL.

4) Continue on to the next section “Setting the Differential Value”.

Setting the Differential Value

1) Assuming DIFFERENTIAL has been enabled and a value is being displayed to the right of the DIFFERENTIAL label, press the ENTER key to display the Digits Edit Box.

2) Press the UP and DOWN arrow keys to scroll the highlighted value.

3) Press the LEFT and RIGHT arrow keys to scroll the digit locations.

4) Repeat steps 2 & 3 until the DIFFERENTIAL value is correctly displayed.

5) Press the OK key to set the DIFFERENTIAL value and return to the menu

screen.

6) Finally, press the MEAS key to return to the measurement screen and begin

taking readings.

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CHAPTER ELEVEN DATA STORAGE – SETUP, EDIT, & VIEW FILES

11.1 Introduction to Grid and Sequential file formats

The CMXDL is equipped with two data file format options, GRID LOG and SEQ LOG. The GRID file format is very similar to a spreadsheet format found in popular software programs like Excel. A GRID is simply a table of readings. A location in a grid is specified by giving a row and column coordinate. The rows are numbered from 1 to 999 and the columns are labeled from A to ZZ (999 Rows & 52 Colu mns). The sequential file format can be viewed as a file as a single column of up to 512 possible rows (readings), and a column of corresponding identifiers associated with each individual reading. The identifier can be a combination of up to 10 numeric, alpha, or special characters listed above, while the file name can consist of a combination of up to 20 of the same character set. Note: The identifier cannot start or end with a special character. Once a start and end ID are entered into the CMXDL and the log created, the CMXDL will automatically generate all the identifiers within that range.

The following character set listed below are all the allowable characters that will be used for both file formats: GRID & SEQ LOG. Any combination of these characters

can be used for creating a Name and Note regardless of the selected format. The allowable characters are as follows:

Numeric characters: 0 – 9 Alpha Characters: A – Z Special Characters: ! ‘ _ # space / . – ( )

Multiple grids can be created and stored until the CMXDL’s memory is full. If the user attempts to store a new file in the CMXDL and the size of the file exceeds the capacity of memory, the CMXDL will respond with an error message indicating that the memory is unable to store the new file.

The CMXDL can store a total of 16,000+ readings with a corresponding screenshot of the DIGITS or B-SCAN views with every reading, as well as all the CMXDL settings for every individual reading. If the graphics option is disabled, not saving

screenshots, the CMXDL can store a total of 210,000+ readings. The screenshot stored with the reading will depend on what view the CMXDL was in at the time it was

saved. For example, if the view was in B-SCAN, then a B-SCAN will be saved with the reading.

In the sections that follow, the procedures for creating, using, and editing GRID’s and SEQ LOG’s have been combined together for the purpose of similarity in overall

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functionality and structure. The illustrations below are snapshots of typical GRID and

SEQ LOG file formats:

Grid File Formats

Sequential Log Formats

Important Note: For the duration of this chapter, all references to GRIDS and SEQ LOGS should be considered synonymous with references to FILES.

11.2 Creating a new Grid or Seq uential Log (File)

Important Note: This entire section is a step by step guide to successfully create a

grid or sequential log. The instructions must be used in the sequential order specified, as follows:

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Creating a Name

Grid/Seq Log Name : Can contain a combination of up to 20 numeric, alpha,

or special characters listed in the first section of this chapter.

Grid Log Sequential Log

1) Press the MENU key once to activate the menu items tab. Press the MENU key multiple times to tab right, and the ESC key multiple times to tab left, until the DATA menu is highlighted and displaying the submenu items.

2) Use the UP and DOWN arrow keys to scroll through the sub menu items until NEW is highlighted.

3) Press the LEFT & RIGHT arrow keys to toggle the data formats – GRIG LOG & SEQ LOG.

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Grid Log Sequential Log

4) Press the ENTER key to display the new Grid or Seq Edit Box.

5) Use the UP and DOWN arrow keys to scroll through the new Grid or Seq List Items until NAME is highlighted.

6) Press the ENTER key to activate the Alpha Edit Box.

7) Use the UP, DOWN, LEFT, & RIGHT arrow keys to highlight the appropriate alpha characters.

8) Press the ENTER key to select a character and advance to the next field of the Grid or Seq Name.

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9) Use the CLR key to backspace if necessary.

10) Repeat steps 6 - 9 until the Grid or Seq Name (File Name) is completed.

11) Press the OK key to save the Grid or Seq Name and return to the Grid or

Seq List Items menu, or ESC to cancel entering the Grid or Seq Name (File Name).

Creating a Note

Grid/Seq Log Note: Can contain a combination of up to 20 numeric, alpha, or

special characters listed in the first section of this chapter.

Grid Log Sequential Log

1) Assuming the Grid or Seq List Items are displayed, u se the UP and DOWN arrow keys to scroll through the new Grid or Seq List Items until NOTE is highlighted.

2) Press the ENTER key to activate the Alpha Edit Box.

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3) Use the UP, DOWN, LEFT, & RIGHT arrow keys to highlight the appropriate alpha characters.

4) Press the ENTER key to select a character and advance to the next field of the Grid or Seq Note.

5) Use the CLR key to backspace if necessary.

6) Repeat steps 3 through 5 until the Grid or Seq Note is completed.

7) Press the OK key to save the Grid or Seq Note and return to the Grid or

Seq List Items menu, or ESC to cancel entering the Grid or Seq Note.

Setting the Coordinates or Start & Stop ID’s

Grid: A grid is defined by using coordinates to define the Top Left and the Bottom Right corners of the grid. Alpha coordinates are horizontal across the

top, and numeric coordinates are vertical down the side. Therefore, to define the top left corner of the grid, there will be an (X,Y) coordinate. Where X is an alpha column location across the top and Y is a numeric row location down the side. Use the same logic when choosing the lower right corner. An individual grid can be up to 999 rows and 52 columns.

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Sequential: The sequential file format can be viewed as a file as a single column of up to 512 possible rows (readings), and a column of corresponding

identifiers associated with each individual reading. The identifier can be a combination of up to 10 numeric, alpha, or special characters listed above, while the file name can consist of a combination of up to 20 of the same character set. Note: The identifier cannot start or end with a special character. Once a start and end ID are entered into the CMXDL and the log created, the

CMXDL will automatically generate all the identifiers within that range.

Setting the Top Left(Grid) or Start ID(Seq)

Grid Log Sequential Log

1) Use the UP and DOWN arrow keys to scroll through the new Grid or Seq List Items until TOP LEFT or START ID is highlighted.

2) Press the ENTER key to activate the Coordinate or Start ID Edit Box.

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Grid Log Sequential Log

3) GRID LOG: Use the LEFT, & RIGHT arrow keys to scroll the Columns, and the UP, DOWN arrow keys to scroll the Rows.

SEQ LOG: Use the UP, DOWN, LEFT, & RIGHT arrow keys to highlight the appropriate alpha characters. Press the ENTER key to select a character and advance to the next character field, in conjunction with using the CLR

key to backspace if necessary.

4) Press the OK key to select the coordinate or start ID and return to the Grid or Seq List Items screen, or ESC to cancel the selection and return to the

Grid or Seq List Items menu.

Setting the Bottom Right(Grid) or End ID(Seq)

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Grid Log Sequential Log

1) Use the UP and DOWN arrow keys to scroll through the new Grid or Seq List Items until LOWER RIGHT or END ID is highlighted.

2) Press the ENTER key to activate the Coordinate or End ID Edit Box.

Grid Log Sequential Log

3) GRID LOG: Use the LEFT, & RIGHT arrow keys to scroll the Columns, and the UP, DOWN arrow keys to scroll the Rows.

SEQ LOG: Use the UP, DOWN, LEFT, & RIGHT arrow keys to highlight the appropriate alpha characters. Press the ENTER key to select a character

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and advance to the next character field, in conjunction with using the CLR

key to backspace if necessary.

4) Press the OK key to select the coordinate or end ID and return to the Grid or Seq List Items screen, or ESC to cancel the selection and return to the

Grid or Seq List Items menu.

Note: If there is not enough memory available to create the grid or sequential

log, an error message box “NOT ENOUGH MEMORY“ will be displayed. Press the OK or ESC key to return to the Grid or Seq List Items menu. It may be necessary to free some memory in the CMXDL at this time. Refer to page 103 for more information on Deleting a File.