Неруйнівний контроль. Ультразвукове вимірювання товщини

EN 14127:2011
en: Non-destructive testing - Ultrasonic thickness measurement

EUROPEAN STANDARD

NORME EUROPEENNE

EUROPAISCHE NORM

ICS 19.100
Supersedes EN 14127:2004

English Version
Non-destructive testing - Ultrasonic thickness measurement

This European Standard was approved by CEN on 25 December 2010.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

EUROPEAN COMMITTEE FOR STANDARDIZATION

Management Centre: Avenue Marnix 17, B-1000 Brussels

Contents
Page
Foreword 4
1 Scope 5
2 Normative references 5
3 Terms and definitions 5
4 Measurement modes 5
5 General requirements 7
5.1 Instruments 7
5.2 Probes 7
5.3 Couplant 7
5.4 Reference blocks 7
5.5 Test objects 7
5.6 Qualification of personnel 8
6 Application of the technique 8
6.1 Surface conditions and surface preparation 8
6.2 Technique 8
6.2.1 General 8
6.2.2 Measurement during manufacture 9
6.2.3 In-service measurement of residual wall thickness 9
6.3 Selection of probe 9
6.4 Selection of instrument 10
6.5 Materials different from the reference 10
6.6 Special measuring conditions 10
6.6.1 General 10
6.6.2 Measurements at temperatures below 0 6.6.3 Measurements at elevated temperatures 11
6.6.4 Hazardous atmospheres 11
7 Instrument setting 11
7.1 General 11
7.2 Methods 12
7.2.1 General 12
7.2.2 Digital thickness instruments 12
7.2.3 7.3 Check of settings 13
8 Influence on accuracy. 14
8.1 Operational conditions 14
8.1.1 Surface conditions 14
8.1.2 Surface temperature 14
8.1.3 Metallic coating 15
8.1.4 Non-metallic coating 15
8.1.5 Geometry 16
8.2 Equipment 17
8.2.1 Resolution 17
8.2.2 Range 17
8.3 Evaluation of accuracy 18
8.3.1 General 18
8.3.2 Influencing parameters 18
8.3.3 Method of calculation 18
9 Influence of materials 18
9.1 General 18
9.2 Inhomogeneity 18
9.3 Anisotropy 18
9.4 Attenuation 18
9.5 Surface conditions 18
9.5.1 General 18
9.5.2 Contact surface 19
9.5.3 Reflecting surface 19
9.5.4 Corrosion and erosion 20
10 Test report 20
10.1 General 20
10.2 General information 20
10.3 Inspection data 21
Annex A (informative) Corrosion in vessels and piping 22
A.1 General 22
A.2 Measurement of general corrosion 22
A.2.1 Instrument 22
A.2.2 Probes 22
A.2.3 Setting of the instrument 22
A.2.4 Measuring 23
A.3 Measurement of corrosion with pitting 23
A.3.1 Instrument 23
A.3.2 Probes 23
A.3.3 Setting of the instrument 23
A.3.4 Measuring 23
Annex В? (informative) Instrument settings 29
Annex C (informative) Parameters influencing accuracy 31
C.1 Parameters influencing accuracy 31
C.2 Methods of calculation 33
Annex D (informative) Measuring technique selection 36
Bibliography 40Foreword
This document (EN 14127:2011) has been prepared by Technical Committee CEN/TC138 "Non-destructive testing”, the secretariat of which is held by AFNOR.
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by August 2011, and conflicting national standards shall be withdrawn at the latest by August 2011.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 14127:2004, which has been editorially revised, in order to take into account the new edition ofEN 1330-4:2010.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. 1 Scope
This European Standard specifies the principles for ultrasonic thickness measurement of metallic and non-metallic materials by direct contact, based on measurement of time-of-flight of ultrasonic pulses only.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
EN 583-2, Nondestructive testing — Ultrasonic examination — Part 2: Sensitivity and range setting
EN 1330-4:2010, Nondestructive testing — Terminology — Part 4: Terms used in ultrasonic testing
3 Terms and definitions
For the purposes of this document, the terms and definitions given in EN 1330-4:2010 apply.
4 Measurement modes
The thickness of a part or structure is determined by accurately measuring the time required for a short ultrasonic pulse generated by a transducer to travel through the thickness of the material once, twice or several times.
The material thickness is calculated by multiplying the known sound velocity of the material with the transit time and dividing by the number of times the pulse transits the material wall.
This principle can be accomplished by applying one of the following modes, see Figure 1:
a) Mode 1 : Measure the transit time from an initial excitation pulse to a first returning echo, minus a zero correction to account for the thickness of the transducer wear surface and the couplant layer (single echo mode).
b) Mode 2 : Measure the transit time from the end of a delay line to the first backwall echo (single echo delay line mode).
c) Mode 3 : Measure the transit time between back-wall echoes (multiple echoes).
d) Mode 4 : Measure the transit time for a pulse travelling from the transmitter to a receiver in contact with the back-wall (through transmission mode).

D transmission pulse indication
E1 to E3 back-wall echoes
F interface echo
G delay path
H received pulse
Figure 1 — Measurement modes
5 General requirements
5.1 Instruments
Thickness measurement can be achieved by using the following types of instruments:
a) dedicated ultrasonic thickness measurement instruments with numerical display showing the measured value;
b) dedicated ultrasonic thickness measurement instruments with numerical display showing the measured value and c) instruments designed primarily for detection of discontinuities with See 6.4.
5.2 Probes
The following types of probes are used, these are generally longitudinal wave probes:
—? dual element probes;
—? single transducer probes.
See 6.3.
5.3 Couplant
Acoustic contact between probe (probes) and material has to be provided, normally by application of a fluid or gel.
The couplant shall not have any adverse effect on the test object, the equipment or represent a health hazard to the operator.
For couplant to be used in special measuring conditions see 6.6.
The coupling medium should be chosen to suit the surface conditions and the irregularities of the surface to ensure adequate coupling.
5.4 Reference blocks
The measuring system shall be calibrated on one or more samples or reference blocks representative of the object to be measured, i.e. having comparable dimensions, material and structure. The thickness of the blocks or the steps should cover the range of thickness to be measured. Either the thickness or the sound velocity of the reference blocks shall be known.
5.5 Test objects
The object to be measured shall allow for ultrasonic wave propagation.
There shall be free access to each individual area to be measured.
The surface of the area to be measured shall be free of all dirt, grease, lint, scale, welding flux and spatter, oil or other extraneous matter that could interfere with the examination.
If the surface is coated, the coating shall have good adhesion to the material. Otherwise it shall be removed.
When measuring through coating its thickness and sound velocity need to be known unless mode 3 is used.
For further details, see Clause 8.
5.6 Qualification of personnel
An operator performing ultrasonic thickness measurement according to this document shall have a basic knowledge of the physics of ultrasonics, and a detailed understanding and training related to ultrasonic thickness measurements. In addition, the operator shall have knowledge of the product and material to be measured.
It is assumed that ultrasonic thickness testing is performed by qualified and capable personnel. In order to prove this qualification, it is recommended to certify the personnel in accordance with EN 473 or equivalent.
Note that for pressure equipment in categories III and IV according to Directive 97/23/EC, Annex I, 3.1.3: the personnel must be approved by a third-party organization recognized by a Member State.
6 Application of the technique
6.1 Surface conditions and surface preparation
Using the pulse-echo method means that the ultrasonic pulse has to pass the contact surface between test object and the probe at least twice: when entering the object and wh