Waygate Technologies DMS Go+ Operating Manual

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)

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),

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
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
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
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
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

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.
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.
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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.
-
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.
-
-
-
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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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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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
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
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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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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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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
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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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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+
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