DMS Go+
Technical Reference and Operating Manual
This edition 4 (05/2014) applies to the software version 3.20 (April 2, 2014)
You will find the software version and the serial number of your instrument at CONFIG - ABOUT.
© GE Sensing & Inspection Technologies GmbH | Technical content subject to change without notice.
Function groups and functions
DMS Go+ Edition 4 (05/2014) 0-3
Function groups and functions (cont'd)
0-4 Edition 4 (05/2014) DMS Go+
Status display icons Power level indicators
Icon Meaning
SD memory card is inserted,
flashes when the SD card is accessed
Display memory active (Function FREEZE),
display is „frozen“.
Measurement mode S-IP, DUAL
Measurement mode S-PEAK, S-FLANK
Measurement mode DUAL-MULTI
Alarm threshold exceeded or fallen below
Reminder for calibration
Icon Meaning
Battery charge level,
remaining operating time
in hours (approximate value)
Charger/power adapter is connected,
percentage of battery charge level
(approximate value)
Warning: Low battery charge level,
remaining operating time
in minutes (approximate value)
DMS Go+ Edition 4 (05/2014) 0-5
Basic key functions
1
2
3
4
5
1 Function key 1, functions are context-dependent
2 Function key 2, functions are context-dependent; keys 1 and 2 simultaneously: Save screen shot
3 Keypad, navigation between function groups and functions, changing settings
4 Function key 3, functions are context-dependent
5 Function key 4, function individually assignable (CONFIG – FUNC KEY),
0-6 Edition 4 (05/2014) DMS Go+
Navigation
Keys Function
Navigation between function groups,
adjusting values
Navigation between functions
within a function group
Changing the display orientation (landscape - portrait)
DMS Go+ Edition 4 (05/2014) 0-7
0-8 Edition 4 (05/2014) DMS Go+
Contents
0 Overview
Function groups and functions . . . . . . . . . 0-3
Function groups and functions (cont'd). . . 0-4
Status display icons . . . . . . . . . . . . . . . . . 0-5
Power level indicators. . . . . . . . . . . . . . . . 0-5
Basic key functions . . . . . . . . . . . . . . . . . . 0-6
Navigation. . . . . . . . . . . . . . . . . . . . . . . . . 0-7
1 Introduction
1.1 Safety information . . . . . . . . . . . . . . . . . 1-2
Battery operation . . . . . . . . . . . . . . . . . . . 1-2
Software . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
Defects/errors and exceptional stresses. . 1-3
1.2 Important information on
wall thickness measurement . . . . . . . . . 1-4
Prerequisites for the use of ultrasonic
thickness gauges . . . . . . . . . . . . . . . . . . . 1-4
Limits of ultrasonic testing . . . . . . . . . . . . 1-5
Ultrasonic wall thickness measurement . . 1-5
Effect of the test object material . . . . . . . . 1-6
Effect of temperature variations . . . . . . . . 1-6
Measurement of remaining wall thickness 1-6
Choice of the probe. . . . . . . . . . . . . . . . . . 1-7
Use of couplants . . . . . . . . . . . . . . . . . . . . 1-7
Doubling of measured value . . . . . . . . . . . 1-7
1.3 Important information on wall thickness
measurement using the DMS Go+ . . . . 1-8
Probe zero offset. . . . . . . . . . . . . . . . . . . . 1-8
Measuring accuracy . . . . . . . . . . . . . . . . . 1-8
Probes. . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-9
1.4 The DMS Go+ . . . . . . . . . . . . . . . . . . . . 1-12
Overview of functions . . . . . . . . . . . . . . . 1-12
Options . . . . . . . . . . . . . . . . . . . . . . . . . . 1-14
1.5 Wall thickness measurement
using the DMS Go+. . . . . . . . . . . . . . . . 1-15
Principle of ultrasonic measurement. . . . 1-15
Dual mode (measurement mode DUAL). 1-16
Single-element mode (measurement
modes S-IP, S-PEAK, S-FLANK) . . . . . . 1-17
Multi-echo mode
(measurement mode DUAL-MULTI). . . . 1-17
DMS Go+ Edition 4 (05/2014) 0-1
Contents
TopCOAT method
(measurement mode TOP-COAT) . . . . . 1-18
Auto-V (measurement mode AUTO-V). . 1-19
B-scan. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-20
Display orientation . . . . . . . . . . . . . . . . . 1-21
1.6 The USM Go+ . . . . . . . . . . . . . . . . . . . . 1-22
1.7 How to use this manual . . . . . . . . . . . . 1-22
Overview . . . . . . . . . . . . . . . . . . . . . . . . . 1-23
1.8 Layout and presentation in
this manual . . . . . . . . . . . . . . . . . . . . . . 1-24
Attention and note symbols. . . . . . . . . . . 1-24
Listings . . . . . . . . . . . . . . . . . . . . . . . . . . 1-24
Operating steps. . . . . . . . . . . . . . . . . . . . 1-24
2 Standard package and accessories
2.1 Standard package . . . . . . . . . . . . . . . . . . 2-2
2.2 Add-on functions . . . . . . . . . . . . . . . . . . 2-3
2.3 Preconfigured function packages. . . . . 2-4
2.5 Recommended probe cables . . . . . . . . 2-10
2.6 Recommended accessories. . . . . . . . . 2-12
3 Initial start-up
3.1 Instrument positioning . . . . . . . . . . . . . . 3-2
3.2 Power supply. . . . . . . . . . . . . . . . . . . . . . 3-2
Operation with charger/power adapter . . . 3-2
Operation using batteries . . . . . . . . . . . . . 3-4
Charging the batteries. . . . . . . . . . . . . . . . 3-8
3.3 Connecting a probe . . . . . . . . . . . . . . . . 3-9
Dual-type connectors . . . . . . . . . . . . . . . . 3-9
Single-type connectors . . . . . . . . . . . . . . . 3-9
3.4 Inserting the SD memory card . . . . . . . 3-10
3.5 Starting the DMS Go+ . . . . . . . . . . . . . . 3-11
Powering On . . . . . . . . . . . . . . . . . . . . . . 3-11
Powering Off . . . . . . . . . . . . . . . . . . . . . . 3-12
Factory default setting (Reset) . . . . . . . . 3-12
2.4 Recommended probes . . . . . . . . . . . . . . 2-5
0-2 Edition 4 (05/2014) DMS Go+
Contents
4 Principles of operation
4.1 Overview of operator's controls . . . . . . 4-2
4.2 Display screen . . . . . . . . . . . . . . . . . . . . 4-3
Display modes . . . . . . . . . . . . . . . . . . . . . 4-3
Functions on the display screen . . . . . . . . 4-5
Icons and information . . . . . . . . . . . . . . . . 4-5
Display of reading . . . . . . . . . . . . . . . . . . . 4-6
4.3 Navigation and function keys . . . . . . . . 4-7
Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Function keys . . . . . . . . . . . . . . . . . . . . . . 4-7
Power key . . . . . . . . . . . . . . . . . . . . . . . . . 4-7
Key combinations . . . . . . . . . . . . . . . . . . . 4-8
4.4 Operational concept . . . . . . . . . . . . . . . . 4-9
Changing the display views . . . . . . . . . . . 4-9
Selecting and setting functions. . . . . . . . 4-10
5 Operation
5.1 Default settings . . . . . . . . . . . . . . . . . . . . 5-2
Language setting . . . . . . . . . . . . . . . . . . . 5-2
Units setting . . . . . . . . . . . . . . . . . . . . . . . 5-3
Resolution setting . . . . . . . . . . . . . . . . . . . 5-3
Radix. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5-4
Last reading . . . . . . . . . . . . . . . . . . . . . . . 5-4
Date format, Date, and Time. . . . . . . . . . . 5-5
Selecting the instrument orientation . . . . . 5-6
Display orientation . . . . . . . . . . . . . . . . . . 5-6
Assignment of function key 4 . . . . . . . . . . 5-7
Function lockout . . . . . . . . . . . . . . . . . . . . 5-8
Password protection . . . . . . . . . . . . . . . . 5-10
Power saving mode . . . . . . . . . . . . . . . . 5-12
Configuring data boxes . . . . . . . . . . . . . . 5-13
5.2 Default settings of the display. . . . . . . 5-15
Setting the brightness . . . . . . . . . . . . . . . 5-15
Selecting the color scheme. . . . . . . . . . . 5-16
DMS Go+ Edition 4 (05/2014) 0-3
Contents
5.3 Operating modes and views . . . . . . . . 5-17
Changing the operating mode or view . . 5-17
5.4 Saving the settings . . . . . . . . . . . . . . . . 5-18
Loading settings . . . . . . . . . . . . . . . . . . . 5-19
Deleting settings . . . . . . . . . . . . . . . . . . . 5-19
5.5 Preparing for measurements . . . . . . . . 5-20
Choosing the probe type. . . . . . . . . . . . . 5-21
Choosing the measurement mode . . . . . 5-22
5.6 Carrying out the calibration. . . . . . . . . 5-24
Calibrations . . . . . . . . . . . . . . . . . . . . . . . 5-24
Probe zero offset. . . . . . . . . . . . . . . . . . . 5-25
Calibration to zero and to sound velocity 5-27
Setting the sound velocity . . . . . . . . . . . . 5-31
5.7 Carrying out measurements . . . . . . . . 5-32
5.8 A-scan configuration . . . . . . . . . . . . . . 5-33
Setting the display range . . . . . . . . . . . . 5-33
Setting the gain . . . . . . . . . . . . . . . . . . . . 5-34
Selecting the display update rate . . . . . . 5-35
Selecting the rectification mode . . . . . . . 5-36
Setting the probe delay . . . . . . . . . . . . . . 5-36
5.9 Setting the gates . . . . . . . . . . . . . . . . . . 5-37
Task of the gates. . . . . . . . . . . . . . . . . . . 5-37
Gate start . . . . . . . . . . . . . . . . . . . . . . . . 5-37
Gate width . . . . . . . . . . . . . . . . . . . . . . . . 5-38
Gate threshold. . . . . . . . . . . . . . . . . . . . . 5-38
5.10 Configuring alarm functions . . . . . . . . 5-39
Minimum value alarm . . . . . . . . . . . . . . . 5-39
Maximum value alarm . . . . . . . . . . . . . . . 5-39
5.11 MIN/MAX mode . . . . . . . . . . . . . . . . . . . 5-40
Switching the MIN/MAX mode on . . . . . .5-41
Clearing a sequence of measurements . 5-41
5.12 Thickness profiles with the B-scan . . . 5-42
Switching the B-scan display on . . . . . . . 5-43
Setting the display time . . . . . . . . . . . . . . 5-43
Setting the waiting time . . . . . . . . . . . . . . 5-44
Minimum value line . . . . . . . . . . . . . . . . . 5-44
Recording a B-scan. . . . . . . . . . . . . . . . . 5-45
0-4 Edition 4 (05/2014) DMS Go+
Contents
5.13 Differential value display . . . . . . . . . . . 5-46
Switching the differential value
display on . . . . . . . . . . . . . . . . . . . . . . . . 5-46
5.14 A-scan view . . . . . . . . . . . . . . . . . . . . . . 5-47
5.15 Other functions . . . . . . . . . . . . . . . . . . . 5-48
Saving calibration block data . . . . . . . . . 5-48
Calibration reminder . . . . . . . . . . . . . . . . 5-50
Temperature compensation . . . . . . . . . . 5-51
Display freeze (FREEZE) . . . . . . . . . . . . 5-52
Gate magnifier (ZOOM) . . . . . . . . . . . . . 5-53
5.16 Enabling options (Upgrade). . . . . . . . . 5-54
6 Data Recorder
6.1 Overview of functions . . . . . . . . . . . . . . 6-2
6.2 File types . . . . . . . . . . . . . . . . . . . . . . . . . 6-4
File type LINEAR . . . . . . . . . . . . . . . . . . . 6-4
File type CUSTOM LINEAR . . . . . . . . . . . 6-5
File type CUSTOM POINT . . . . . . . . . . . . 6-5
File type GRID . . . . . . . . . . . . . . . . . . . . . 6-6
File type CUSTOM GRID . . . . . . . . . . . . . 6-6
File type BOILER . . . . . . . . . . . . . . . . . . . 6-7
6.3 Master comment list . . . . . . . . . . . . . . . . 6-8
Creating a master comment list . . . . . . . . 6-8
Changing master comments . . . . . . . . . . . 6-9
6.4 Working with files . . . . . . . . . . . . . . . . . 6-11
Creating a new file . . . . . . . . . . . . . . . . . 6-11
Deleting files . . . . . . . . . . . . . . . . . . . . . . 6-13
6.5 Saving measurement results. . . . . . . . 6-14
Loading a file. . . . . . . . . . . . . . . . . . . . . . 6-14
Saving readings . . . . . . . . . . . . . . . . . . . 6-15
Special measuring point functions . . . . . 6-16
Selecting individual measuring points. . . 6-16
Clearing a reading. . . . . . . . . . . . . . . . . . 6-17
Overwriting readings . . . . . . . . . . . . . . . . 6-17
Saving readings with A-scans . . . . . . . . . 6-18
Adding comments . . . . . . . . . . . . . . . . . . 6-20
Editing a file comment list . . . . . . . . . . . . 6-22
DMS Go+ Edition 4 (05/2014) 0-5
Contents
6.6 Editing files . . . . . . . . . . . . . . . . . . . . . . 6-24
Expanding the file capacity . . . . . . . . . . . 6-24
Deleting parts of a file . . . . . . . . . . . . . . . 6-26
Editing header data. . . . . . . . . . . . . . . . . 6-27
Adding a Microgrid . . . . . . . . . . . . . . . . . 6-29
Automatic advance . . . . . . . . . . . . . . . . . 6-33
6.7 Evaluations . . . . . . . . . . . . . . . . . . . . . . 6-36
Viewing statistical evaluations . . . . . . . . 6-36
Changing the view (Spread – List) . . . . . 6-38
Viewing stored reading attachments. . . . 6-39
6.8 Documenting measurements. . . . . . . . 6-40
Data export . . . . . . . . . . . . . . . . . . . . . . . 6-40
Screen shots . . . . . . . . . . . . . . . . . . . . . . 6-41
7 Special functions of the DMS Go+ TC
7.1 Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . 7-2
7.2 Measurement mode Auto-V . . . . . . . . . . 7-6
Applications. . . . . . . . . . . . . . . . . . . . . . . . 7-6
Choosing the probe. . . . . . . . . . . . . . . . . . 7-6
Activating Auto-V. . . . . . . . . . . . . . . . . . . . 7-6
Zeroing for Auto-V. . . . . . . . . . . . . . . . . . . 7-7
Checking reference block data . . . . . . . . . 7-7
7.3 Measurement mode TopCOAT. . . . . . . . 7-9
Applications. . . . . . . . . . . . . . . . . . . . . . . . 7-9
Choosing the probe. . . . . . . . . . . . . . . . . . 7-9
Activating TopCOAT . . . . . . . . . . . . . . . . . 7-9
Zeroing for TopCOAT . . . . . . . . . . . . . . . 7-10
Checking reference block data . . . . . . . . 7-10
Sound velocity in the test object.. . . . . . . 7-11
Calibration to the sound velocity . . . . . . . 7-12
Sound velocity in the coating . . . . . . . . . 7-13
8 Maintenance and care
8.1 Instrument care . . . . . . . . . . . . . . . . . . . . 8-2
8.2 Battery care . . . . . . . . . . . . . . . . . . . . . . . 8-2
Battery care. . . . . . . . . . . . . . . . . . . . . . . . 8-2
Charging the batteries. . . . . . . . . . . . . . . . 8-3
8.3 Maintenance . . . . . . . . . . . . . . . . . . . . . . 8-3
0-6 Edition 4 (05/2014) DMS Go+
Contents
8.4 Software updates . . . . . . . . . . . . . . . . . . 8-4
Download of update files . . . . . . . . . . . . . 8-4
Installing an update. . . . . . . . . . . . . . . . . . 8-5
9 Interfaces and Peripherals
9.1 Interfaces. . . . . . . . . . . . . . . . . . . . . . . . . 9-2
Overview. . . . . . . . . . . . . . . . . . . . . . . . . . 9-2
USB interface . . . . . . . . . . . . . . . . . . . . . . 9-3
Service interface (Mini RS232-C) . . . . . . . 9-3
9.2 Peripherals . . . . . . . . . . . . . . . . . . . . . . . 9-4
10 Appendix
10.1 Application notes . . . . . . . . . . . . . . . . . 10-2
General notes . . . . . . . . . . . . . . . . . . . . . 10-2
10.2 Sound velocities . . . . . . . . . . . . . . . . . . 10-4
10.3 Data Recorder file types. . . . . . . . . . . . 10-7
File type LINEAR . . . . . . . . . . . . . . . . . . 10-7
File type GRID . . . . . . . . . . . . . . . . . . . . 10-9
File type CUSTOM LINEAR . . . . . . . . . 10-11
File type CUSTOM GRID . . . . . . . . . . . 10-13
File type CUSTOM POINT . . . . . . . . . . 10-15
File type BOILER . . . . . . . . . . . . . . . . . 10-17
10.4 Flag symbols . . . . . . . . . . . . . . . . . . . . 10-19
10.5 Function directory . . . . . . . . . . . . . . . 10-20
10.6 EU Declaration of Conformity . . . . . . 10-25
10.7 Manufacturer/Service addresses. . . . 10-25
10.8 Environmental protection
regulations. . . . . . . . . . . . . . . . . . . . . . 10-27
WEEE directive (Waste Electrical
and Electronic Equipment) . . . . . . . . . . 10-27
Disposal of batteries . . . . . . . . . . . . . . . 10-28
10.9 Recycling directives . . . . . . . . . . . . . . 10-30
Overview . . . . . . . . . . . . . . . . . . . . . . . . 10-30
Materials to be disposed of separately . 10-33
Other materials and components . . . . . 10-36
Recycling data of the DMS Go+ . . . . . . 10-43
DMS Go+ Edition 4 (05/2014) 0-7
11 Specifications
11.1 Specifications of the DMS Go+ . . . . . . 11-2
Display screen . . . . . . . . . . . . . . . . . . . . 11-2
Display . . . . . . . . . . . . . . . . . . . . . . . . . . 11-3
Connectors . . . . . . . . . . . . . . . . . . . . . . . 11-4
Pulser . . . . . . . . . . . . . . . . . . . . . . . . . . . 11-4
Receiver . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Memory . . . . . . . . . . . . . . . . . . . . . . . . . . 11-5
Environment . . . . . . . . . . . . . . . . . . . . . . 11-6
Protection . . . . . . . . . . . . . . . . . . . . . . . . 11-7
Options . . . . . . . . . . . . . . . . . . . . . . . . . . 11-8
11.2 Specifications according to
EN 12668 . . . . . . . . . . . . . . . . . . . . . . . . 11-9
12 Index
0-8 Edition 4 (05/2014) DMS Go+
Introduction 1
DMS Go+ Edition 4 (05/2014) 1-1
1 Introduction Safety information
ATTENTION
1.1 Safety information
The DMS Go+ has been designed and tested according
to DIN
EN 61010-1: 2011-07, Safety requirements for
electrical equipment for measurement, control and lab
oratory use, and was technically in perfectly safe and
faultless condition when leaving the manufacturing
works.
In order to maintain this condition and to ensure a safe
operation, you should always read the following safety
information carefully before putting the instrument into
operation.
The DMS Go+ is an instrument for materials testing. Any use for medical or any
other applications is not permitted!
The instrument may only be used in industrial environments.
The DMS Go+ is waterproof according to IP67. It can be
operated either with the corresponding lithium-ion bat
teries or with the charger/power adapter. The charger/
power adapter meets the requirements of electrical
safety class II.
-
Battery operation
For the battery operation of the DMS Go+, we recommend the corresponding lithium-ion battery. You should
only use this battery for the battery operation.
You can charge the lithium-ion battery either within the
instrument itself or in an external charger. If a lithium-ion
battery is inserted, charging starts automatically as
soon as you connect the charger/power adapter to the
DMS Go+ and to the mains power supply.
For power supply, please also see Chapter 3.2 Power
supply, page 3-2. For the use of batteries, please also
see Chapter 8.2 Battery care, page 8-2.
Software
According to the current state of the art, software is never completely free from errors. Before using any software-controlled test equipment, it is therefore necessary to make sure that the required functions operate
perfectly in the intended combination.
If you have any questions about the use of your test
equipment, please contact your nearest representative
of GE.
1-2 Edition 4 (05/2014) DMS Go+
Safety information 1 Introduction
Defects/errors and exceptional stresses
If you have reason to believe that a safe operation of
your DMS Go+ is no longer possible, you have to dis
connect the instrument and secure it against unintentional reconnection. Remove the lithium-ion battery.
A safe operation is no longer possible for example
● if the instrument shows visible damages,
● if the instrument no longer operates perfectly,
● after prolonged storage under adverse conditions
(e.g. exceptional temperatures or especially high air
humidity, or corrosive environmental conditions),
● after being subjected to heavy stresses during transportation.
-
DMS Go+ Edition 4 (05/2014) 1-3
1 Introduction Important information on wall thickness measurement
ATTENTION
1.2 Important information on wall thickness measurement
Please read the following information before
using your thickness gauge. It is very import
ant that you understand and observe this information to avoid any errors when using the
instrument that might lead to false measure
ment results. Decisions made on the basis of
false measurement results may lead to prop
erty damages and personal injuries.
Prerequisites for the use of ultrasonic thickness gauges
This operating manual contains essential information on
how to operate your thickness gauge. In addition, there
are a number of factors that affect the measurement re
sults. A description of all these factors would go beyond
the scope of an operating manual. Therefore, only the
most important prerequisites for a safe and reliable ul
trasonic thickness measurement are mentioned here:
-
● Training of the instrument operator (operator)
● Knowledge of special technical measurement re-
quirements and limits
● Choice of the appropriate measuring device
The operation of an ultrasonic measuring device requires proper training in ultrasonic thickness measure-
ment. Proper training comprises for example adequate
knowledge of the following:
● Theory of the propagation of sound waves in materi-
-
als
-
● Effects of the sound velocity of test material
● Behavior of sound waves at interfaces between dif-
ferent materials
● Propagation of the sound beam within the material
● Effect of the surface quality of test material.
-
1-4 Edition 4 (05/2014) DMS Go+
Important information on wall thickness measurement 1 Introduction
Lack of such knowledge could lead to false measurement results with unforeseeable consequences. Information about the existing training opportunities for ultrasonic inspectors and about the qualifications and certificates that can finally be obtained is available at the
national NDT societies or at GE.
GE holds specialized training courses in the field of ultrasonic testing at regular intervals. The scheduled
dates for these courses will be given to you on request.
Limits of ultrasonic testing
The information obtained from ultrasonic tests only refers to those parts of the test object which are covered
by the sound beam of the probe used. Should any con
clusions from the tested parts be applied to the untested
parts of the test object, they should therefore be made
with extreme caution. Such conclusions are generally
only possible in cases where extensive experience of
the components to be tested and proven methods of
statistical data acquisition are available.
Boundary surfaces within the test object can completely
reflect the sound beam, resulting in reflection points
which lie beyond this, for example the component's
backwall, remaining undetected. It is therefore import
ant to make sure that all areas to be tested in the test
object are covered by the sound beam.
Ultrasonic wall thickness measurement
All ultrasonic wall thickness measurements are based
on a time-of-flight measurement of the sound pulse in
the test object. Accurate measurement results therefore
require a constant sound velocity in the test object. This
requirement is generally met in test objects made of
steel, even with different alloying constituents. The vari
ation of sound velocity is so slight that it is only of impor-
tance for high-precision measurements. In other materials, for example nonferrous metals or plastics, the
sound velocity is nevertheless subject to larger varia
tions. These may affect the measuring accuracy.
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DMS Go+ Edition 4 (05/2014) 1-5
1 Introduction Important information on wall thickness measurement
Effect of the test object material
If the material is not homogeneous, the sound waves
may propagate at different velocities in different parts of
the test object. In this case, an average sound velocity
should therefore be taken into account for the instru
ment calibration.
However, the best results are obtained when the instrument is calibrated using a reference block made of the
same material as the test object. This calibration block
should have plane-parallel surfaces and a thickness
corresponding to the maximum thickness of the test ob
ject. The operator
should additionally keep in mind that the sound velocity
is liable to vary substantially due to heat treatments.
This fact must be taken into account when assessing
the accuracy of the wall thickness measured by the in
strument.
If substantial sound velocity variations are expected,
then the instrument calibration should be adjusted to the
actual sound velocity values at shorter time intervals.
Failure to do so may lead to false thickness readings.
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Effect of temperature variations
The sound velocity within the test object also varies
along with material's temperature. This can cause ap
preciable errors in measurements if the instrument has
been calibrated on a cold reference block, whereas the
thickness measurement is carried out on a warm test
object. Such measurement errors can be avoided either
by adjusting the temperature of the reference block
used for calibration or by taking the temperature effect
on the sound velocity into consideration on the basis of
a correction factor obtained from published tables.
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Measurement of remaining wall thickness
The measurement of the remaining wall thickness on
plant components, e.g. pipes, tanks, or reaction vessels
of all types which are corroded or eroded from the in
side, requires a perfectly suitable gauge and special
care in handling the probe.
The operator should always be informed about the corresponding nominal wall thicknesses as well as about
the likely amount of wall thickness losses.
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1-6 Edition 4 (05/2014) DMS Go+
Important information on wall thickness measurement 1 Introduction
Choice of the probe
The probe used for the measurement must be in good
condition, i.e. its coupling face or delay line should not
show any considerable wear. The measuring range (ap
plication range) specified for the corresponding probe in
the data sheets must cover the complete thickness
range to be inspected. The temperature of the test ob
ject must be within the permissible temperature range of
the selected probe.
Use of couplants
The operator must be familiar with the use of the ultrasonic couplant to the effect that the couplant is applied
equally during every measurement so that variations in
the couplant layer thickness and errors in the subse
quent measurement results are avoided. The instrument calibration and the actual wall thickness measurement should be carried out under identical coupling conditions. During this process, the quantities of couplant
used should be as small as possible and a constant
pressure should be applied to the probe.
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In the case of curved coupling faces, for example on
tubes, the dual-element probe used for the measure
ment should be coupled in such a way that its acoustic
separation layer forms an angle of 90° with reference to
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the tube's longitudinal axis.
Doubling of measured value
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A dangerous measuring error in ultrasonic thickness
measurement can occur if the thickness is measured
below the application range (operating range) specified
for the probe used. In this case, the first backwall echo
is too small for an evaluation, whereas the second back
wall echo has an adequately high amplitude and is
therefore evaluated by the instrument. This results in a
wall thickness reading which is twice as large as the ac
tual wall thickness. In order to avoid such measuring errors, the operator must carry out an additional check
measurement using another probe at the limit of the ap
plication range.
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DMS Go+ Edition 4 (05/2014) 1-7
1 Introduction Important information on wall thickness measurement using the DMS Go+
ATTENTION
1.3 Important information on wall thickness measurement using the DMS Go+
Please always read the following information
about the special features in wall thickness
measurement using the DMS Go+. It is abso
lutely necessary that you observe this information in order to always obtain correct
measurement results.
Probe zero offset
High differences in temperature
If the differences in temperature between the storage
and inspection site are high, it is necessary that you wait
approx. 2 minutes before you use the instrument after
connecting the probe.
at temperatures below –10 °C. You should therefore
carry out a 2-point calibration and repeat it in the case
of major temperature jumps.
Couplant residues
In order to ensure a correct probe zero offset, make sure
that you always remove the couplant residues before
carrying out a new measurement after decoupling the
probe.
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Measuring accuracy
Keep in mind that the measuring accuracy is not identical with the display accuracy.
The measuring accuracy depends on the following factors:
● Temperature
● Probe delay line
● Constancy of sound velocity
● Uniformity of surface quality
Temperatures below –10 °C
The probe zero offset does not always function correctly
1-8 Edition 4 (05/2014) DMS Go+
Important information on wall thickness measurement using the DMS Go+ 1 Introduction
Probes
Please note that only probes specified in chapter 2 of
this manual are accepted for the DMS Go+.
V-path correction
The following probes have only one transducer element
and therefore require no V-path correction:
● K 1 SC ● K-PEN ● G5 KB
● G 2 N ● CLF 5 ● CLF 4
● CA 215 ● CA 214 ● CA 211
● CA 211 A ● A DFRP ● A2 DFR
● A2 DFR ● A2 10 M ● 5 M 5 DFR
All probes equipped with a transmitter and a receiver element require a V-path correction due to the inclined position of their transducer elements (with wall thicknesses < 60 mm in steel).
The V-path correction is stored in the DMS Go+ for the
following probes:
● Alpha2 D ● CA 211A ● DA 301
● DA 303 ● DA 312 ● DA 312 B1
● DA 501 EN ● DA 503 EN ● DA 507
● DA 512 ● D 590 ● FH 2 E
● HT 400 A ● KBA 525 ● KBA 560
● OSS 10 ● TC 560 ● D 790
DMS Go+ Edition 4 (05/2014) 1-9
1 Introduction Important information on wall thickness measurement using the DMS Go+
The following probes have been corrected individually
during the manufacturing process; the V-path correction
is stored in the probe. For some of these probes
(marked with *), this was additionally done for the oper
ating mode DUAL-MULTI.
● DA 401 ● DA 403 ● DA 408
● DA 411 ● DA 412* ● DA 451*
● DA 453 ● DA 458 ● DA 461*
● DA 462* ● DA 455 ● DA 465
● DA 467 ● DA 469 ● FH 2 ED REM
Zeroing
The correct zeroing is important for the measuring accuracy of probes equipped with a transmitter and a receiver element. A difference is made between two methods:
1 Zeroing before coupling the probe
(OFF-BLOCK zeroing)
2 Zeroing during probe coupling
(ON-BLOCK zeroing)
Zeroing before coupling the probe (OFF-BLOCK
zeroing)
After powering the DMS Go+ on, the length of the delay
line below the transmitter element is determined at reg
ular intervals whenever the probe is not coupled for the
wall thickness measurement. In this regard, it is import
ant that the coupling face of the probe is free from couplant to a large extent in order to avoid any faulty measurements.
This method is of advantage in cases where rough or
curved surfaces may result in a critical coupling. When
determining wall thicknesses in plastics, only probes
with zeroing before coupling should be chosen:
● DA 401 ● DA 403 ● DA 408
● DA 411 ● DA 412 ● D 790
● FH 2 E ● KBA 525 ● KBA 560
● HT 400 A ● TC 560
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1-10 Edition 4 (05/2014) DMS Go+
Important information on wall thickness measurement using the DMS Go+ 1 Introduction
Zeroing during probe coupling (ON-BLOCK zeroing)
After coupling the probe (but before each individual wall
thickness measurement), the length of the delay line be
low the transmitter element is determined at first. The
actual wall thickness measurement is not carried out till
after that.
This method is of advantage whenever a high stability
and reproducibility of the measured values are required.
For example, if the temperature of the part to be tested
differs largely from that of the probe, the delay lines are
cooled down during coupling and thus reduced, or they
are heated up and thus extended. Each zero drift is thus
compensated for immediately before every wall thick
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ness measurement in the case of these probes:
● DA 301 ● DA 303 ● DA 305
● DA 312 ● DA 312 B... ● DA 315
● DA 317 ● DA 319 ● DA 451*
● DA 453* ● DA 461* ● DA 462*
● DA 465* ● DA 467* ● DA 469*
In the case of probes marked with *, the zero is determined as an arithmetic mean of the two probe delay
lines. For example, probes showing beveled wear can
thus comply with their original measured-value toler
ance better.
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DMS Go+ Edition 4 (05/2014) 1-11
1 Introduction The DMS Go+
1.4 The DMS Go+
Overview of functions
The DMS Go+ is a portable thickness gauge with an integrated data recorder You can use this instrument for
measuring the wall thickness on a large variety of com
ponents, for example on tubes, pressure vessels, and
other equipment parts whose wall thickness is subject to
a gradual reduction.
This makes the DMS Go+ especially suitable for measurement tasks for the documented corrosion test.
Special features of the DMS Go+
● high measuring stability and reliability thanks to the
zero crossing method
● automatic gain control for an improved reproducibility
during corrosion tests
● dust-tight and waterproof housing according to IP67
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● low weight (845 g incl. batteries)
● long operating time (8 hours) due to lithium-ion bat-
tery with internal and external charging possibility
● one-handed operation is possible
● high-resolution color screen (800 x 480 pixels) for the
display of measured values and A-scan
● enlarged display of measured values which are easy
to read even from a greater distance
● color-coded display of gates for easy differentiation
1-12 Edition 4 (05/2014) DMS Go+
The DMS Go+ 1 Introduction
● high memory capacity with 2GB SD card. SD cards
with a memory capacity up to 16
GB can be used.
● measuring range 0.25 … 14000 mm (steel), depending on the probe, material, and surface
● digital resolution 0.01 mm or 0.1 mm (selectable)
over the entire measuring range
● units selectable between inch and mm
● integrated data recorder for 100,000 measurements
per file. Several files can be saved to the SD card.
● up to 16 user-definable comments for every file format with up to 16 alphanumeric characters per measuring point
● automatic probe detection with dialog probes, optimized setup and power of the instrument, especially
higher measuring accuracy thanks to the individual Vpath correction data stored in the corresponding
probe used
● MicroGrid function for testing the direct surroundings
of the measuring point
● single-element operating mode with measurement at
echo flank or echo peak
● MIN operating mode with increased pulse repetition
frequency for detecting the smallest reading in a se
ries of measurements
● Dual-Multi operating mode for measuring through
coatings
● adjustable minimum and maximum limits with alarm
signaling through color change of the reading
● locking function to prevent unintentional changes to
the adjustment values
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DMS Go+ Edition 4 (05/2014) 1-13
Options
Various options extend the basic functions of the DMS
Go+ and can be enabled by a code in each case.
DMS Go+ Base
● Basic version, for universal
ultrasonic wall thickness measurement
DMS Go+ TC
● TopCOAT technology for the simultaneous measurement of coating thickness and metal thickness
● Auto-V function for the wall thickness measurement
of components with unknown sound velocity, without
calibration block during the measurement
DMS Go+ DR
● Extended data recorder
DMS Go+ Advanced
● TopCOAT technology for the simultaneous measurement of coating thickness and metal thickness
● Auto-V function for the wall thickness measurement
of components with unknown sound velocity, without
calibration block during the measurement
● Extended data recorder
1-14 Edition 4 (05/2014) DMS Go+